2013 Subject Index: Materials

• Nanoscale Evaluation of Effect of RAP on Virgin Asphalt Binder Properties
  Abstract: In this paper, various nano and macro-mechanical techniques were used to study the effect of Reclaimed Asphalt Pavement (RAP) binder on the micro-structure and properties of a virgin asphalt binder and to evaluate the degree of blending that occurs between those binders. To this end, different atomic force microscopy (AFM) experiments (i.e. AFM tapping mode imaging, AFM nano-indentation, AFM force spectroscopy experiments) were conducted on a virgin asphalt binder, recovered RAP binder, and their composite. In addition, the dynamic shear rhoemeter (DSR) tests were conducted on the evaluated binders, and the dynamic modulus tests (E*) were performed on mixtures prepared using those binders to evaluate the degree of RAP blending and compare it with those obtained using the AFM test results. The results of the AFM images indicated that blending between the RAP and virgin binders occurs at the nano/micro-scale level in the composite binder at a fairly uniform manner. Furthermore, the nano-indentation test results indicated that the composite asphalt binder had significantly lower modulus than the RAP binder and closer to the virgin binder; however, the virgin binder modulus was still significantly lower than that of the composite. The force spectroscopy results indicated that the RAP had adverse effects on the adhesion properties of the composite binder. The results of DSR tests showed similar trends to that observed using the AFM nano-indentation results; however, the DSR was found to underestimate the effect of the RAP on the mechanical properties of the composite. Finally, the AFM test results suggested that about 85% of RAP was effective in the composite.
  Authors: Nazzal, Munir D.; Mogawer, Walaa S.; Kaya, Savas; Bennert, Thomas A.
  Authors: Nazzal, Munir D.; Mogawer, Walaa S.; Kaya, Savas; Bennert, Thomas A.
  Year: 2013
  Document Type: Paper
  Subject: Materials; Pavements
  Session: 307
  Paper Number: 13-0153
• Mechanical Analysis of Failure Processes at Bitumen-Aggregate Interface
  Abstract: The experience reported herein focuses on the advanced characterization of adhesive/cohesive failure at bitumen/aggregate interfaces. A modified Pneumatic Adhesion Tensile Testing Instrument (PATTI) was developed to integrate the conventional measure of pressure with the additional measure of vertical displacement. The measurement of vertical displacement was used to estimate the deformation within the bitumen film and therefore the final strain at failure. This provided specific functional characteristics, specifically linked to the possibility of estimating the total work done by the external forces to separate the bitumen/aggregate interfaces. Energy-based criteria for adhesive/cohesive tensile failure were consequently established accounting for the elongation of the bitumen film. The interface bond energy and its stability upon moisture conditioning were then measured for different bitumen-aggregate systems. The bond energy was found to be highly dependent on the specific characteristics of the asphaltic interfaces and primarily connected with bitumen grading and composition. The analysis of the detachment surfaces addressed further relations between the changes recorded in bond energy, the characteristics of the asphalt film and the progressive shift from cohesive to adhesive failure.
  Authors: Merusi, Filippo; Caruso, Alessandro; Chiapponi, Luca; Giuliani, Felice
  Authors: Merusi, Filippo; Caruso, Alessandro; Chiapponi, Luca; Giuliani, Felice
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 655
  Paper Number: 13-0445
• Laser Spectrographic Pattern Matching for Rapid Mineral Aggregate Classification
  Abstract: Mineral aggregates were found to exhibit unique spectral fingerprints or spectral patterns, when subjected to a high irradiance induced by focusing a high powered laser onto very tiny spot on a target aggregate material. These spectral patterns were successfully correlated with engineering material properties of the targeted material. Using multivariate determinant models, the acid insoluble residue content, the presence of D-cracking susceptibility and alkali-silica reactivity were accurately predicted on aggregates supplied by New York, Kansas and Texas DOTs, respectively. The subject technology has the potential to rapidly classify material properties providing material suppliers and transportation agencies with a real time, recording tool for monitoring materials used in highway construction.
  Authors: Chesner, Warren H.; McMillan, Nancy
  Authors: Chesner, Warren H.; McMillan, Nancy
  Year: 2013
  Document Type: Paper
  Subject: Geotechnology; Materials
  Session: 745
  Paper Number: 13-0480
• Influence of Aggregate Packing and Asphalt Binder Characteristics on Performance of Stone Matrix Asphalt
  Abstract: Stone matrix asphalt (SMA) is valued for its high resistance to rutting and durability characteristics. These characteristics of SMA mixtures are mainly the result of the rich asphalt mastic and the good stone-on-stone contact provided by its coarse, gap-graded aggregate structure. SMA has been used in Virginia since 1995 with overall excellent performance. However, with the introduction of the 9.5 mm SMA mix in 2003, the field performance of this mix has been variable. This paper focuses on the laboratory evaluation of asphalt binder and aggregate packing effects on the rutting resistance of SMA, the primary failure mechanism for the SMA-9.5. The objective was to identify defining characteristics of SMA mixtures that impact field performance. Four SMA-9.5 mixtures with known field performance – two good performers, one marginal performer, and one poor performer - were reproduced in the laboratory and tested. Rutting resistance of the mixtures was evaluated using the flow number (FN) obtained from repeated load permanent deformation tests and the asphalt pavement analyzer. In addition, dynamic shear rheometer, bending beam rheometer, and dynamic modulus testing were conducted to characterize the asphalt binder and mixtures stiffness. The results indicated that rutting resistance of SMA was dependent on binder stiffness, binder content, and aggregate structure (gradation, VCA, and Abrams fineness modulus). Mixtures with history of good field performance showed significantly higher FN than the poor performers. Both binder content and aggregate packing (fineness modulus and VCAmix) were lower for the good performing mixtures but binder content appears to have more significant influence on FN – a one percentage point increase over VDOT minimum binder content of 6.3 percent resultant in significant decrease in rutting resistance irrespective of aggregate packing characteristics. It was concluded that combination of traffic characteristics (slow-moving, turning, or stopped), aggregate packing (higher VCAmix, lower Abrams modulus, higher percent passing No. 4 sieve), and binder amount, may have contributed to the observed poor SMA field performance.
  Authors: Apeagyei, Alex K.; McGhee, Kevin Kenneth; Clark, Trenton
  Authors: Apeagyei, Alex K.; McGhee, Kevin Kenneth; Clark, Trenton
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 670
  Paper Number: 13-0622
• Laboratory Validation of Healing-Based Fatigue Endurance Limit for Hot-Mix Asphalt
  Abstract: One of the main requirements of designing perpetual pavements is to determine the endurance limit of Hot Mix Asphalt (HMA). The endurance limit, as applied to HMA and flexible pavement design, is the strain or stress level below which the HMA would endure indefinite fatigue load repetitions and the pavement would not experience bottom-up fatigue cracking. The purpose of this study is to validate the endurance limit for HMA using laboratory beam fatigue tests. A rational procedure was developed to determine the endurance limit of HMA due to healing that occurs during the rest periods between loading cycles. Relating healing to endurance limit makes this procedure unique compared to previous research projects that investigated these concepts separately. An extensive laboratory testing program, including 468 beam fatigue tests, was conducted according to AASHTO T321-03 test procedure as a part of the NCHRP 9-44A project. Six factors that affect the fatigue response of HMA were evaluated: binder grade, binder content, air voids, test temperature, rest period and applied strain. The endurance limit was determined when no accumulated damage occurred indicating complete healing during the rest period after each load application. A threshold rest period of about 5 seconds for a load duration of 0.1 seconds was obtained beyond which no more healing is gained. HMA exhibits endurance limits ranging from 37 micro-strains to 246 micro-strains depending on mixture properties and environmental conditions. The results of this study can be used to design perpetual pavements that can sustain a large number of loads if traffic volumes and vehicle weights are controlled.
  Authors: Souliman, Mena I.; Zeiada, Waleed Abdelaziz; Mamlouk, Michael S.; Kaloush, Kamil E.
  Authors: Souliman, Mena I.; Zeiada, Waleed Abdelaziz; Mamlouk, Michael S.; Kaloush, Kamil E.
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 599
  Paper Number: 13-0691
• Prediction of Asphalt Pavement Surface Characteristics Using Torque Measurements
  Abstract: Continuous increase in traffic volume in the recent years has resulted in greater surface friction loss of asphalt pavements. While the literature presents several ways of aggregate and asphalt mix screening to ensure that surface characteristics are at an acceptable level of friction to control skid-related accidents, the recommended polishing tests using different accelerated polishing devices are time consuming and labor intensive. Therefore, it is imperative that existing polishing devices be improved to significantly shorten the test duration to a level desired by the industry as well as state and federal agencies. This paper aims at addressing this improvement that uses power unit (or motor) to generate energy enough to rotate the polishing disk at constant rotational speed while being pressed against the specimen surface then read the power needed from the display screen for the following steps.Multiple verification techniques including comparison studies and statistical analyses were used to examine the validity of this improvement. It was found that data collected by the power unit was repeatable and able to precisely detect surface deterioration history for different asphalt mixes with different polish susceptibility in a manner similar to conventional friction and texture measuring devices. Hence, aggregates and mixes were classified based on their surface frictional properties. Additionally, results from this study correlated well with results from other studies using conventional methods. Most importantly, it was found to be possible to cut the polishing test time dramatically by using torque values in lieu of conventional surface quantification methods.
  Authors: Khasawneh, Mohammad Ali; Liang, Robert
  Authors: Khasawneh, Mohammad Ali; Liang, Robert
  Year: 2013
  Document Type: Paper
  Subject: Materials; Pavements
  Session: 517
  Paper Number: 13-0473
• Evaluation of Adhesion Properties of Costa Rican Asphalt Mixtures Using Bitumen Bond Strength and Contact-Angle Measurement Tests
  Abstract: Because of the geographic location of Costa Rica, the Country is subjected to one of the highest levels of precipitation in the world. As such, it is to be expected that moisture damage is the most common type of pavement failure in the Country. However, despite the previous fact, little research has been performed in quantifying the affinity of the asphalt binder and aggregates that are used. Consequently, the present study consists of an effort to characterize the strength in the bond between the asphalt binder that is used locally (PG64-22) and several types of aggregates from different parts of the Country (1 limestone and 4 distinct river gravels from several locations). Additionally, the neat asphalt binder was also modified with a commercial SBR, a modifier commonly used in Costa Rica since it is supposed to promote adhesion. To evaluate the strength of the bond between the asphalt binder and the various aggregate combinations, the Bitumen Bond Strength (BBS) test was used. The results were checked by means of a goniometer that measures the contact angle between the asphalt binder and the aggregate surface, which corresponds to a measure of wettability. Finally, a subset of the analyzed asphalt binder and aggregate combinations were used to prepare an HMA mixture and evaluate it under the Hamburg Wheel Tracking Device (HWTD).The BBS results showed differences in behavior due to the effect of moisture on bond strength when changing the aggregate source. Additionally, depending on the aggregate type, different types of failure were observed: cohesive vs. adhesive. A decrease was identified in the bond strength when the SBR was used. However, when using the modifier, the effect of moisture on bond strength was reduced. The BBS results were consistent with the contact angle measurements and with the HWTD results, showing that the test can eventually be implemented as a screening tool.
  Authors: Aguiar-Moya, José Pablo; Loria-Salazar, Luis; Salazar, Jorge; Corrales-Azofeifa, Jose; Villegas, Ernesto; Hajj, Elie Y
  Authors: Aguiar-Moya, José Pablo; Loria-Salazar, Luis; Salazar, Jorge; Corrales-Azofeifa, Jose; Villegas, Ernesto; Hajj, Elie Y
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 655
  Paper Number: 13-0743
• First Observation of Blending-Zone Morphology at Interface of Reclaimed Asphalt Binder and Virgin Bitumen
  Abstract: The challenge in designing recycled asphalt mixtures with a high amount of RAP is to estimate the blending degree between RAP binder and the added virgin bitumen. The extent of blending is crucial in this case as asphalt concrete response is influenced by the final binder properties. This paper focuses on the evaluation of interaction and extent of blending between RAP-binder and virgin bitumen by studying the microstructures of the ‘blending zone’ with atomic force microscopy (AFM). AFM is used to probe the change of microstructural properties from a RAP-binder and virgin bitumen to the blending zone of these two. Averaged microstructural properties have been observed in thin film blends of RAP-binder and pure bitumen. The morphology of the blending zone (spatial extent of about 50 µm) exhibits domains of a wide range of microstructure sizes from 160 nm to 2.07 µm and can be considered to be a completely blended ‘new material’ which has been observed directly for the first time. The fully blended binder properties are found to be in between those of the two individual binders, as could be inferred from the averaged microstructural properties imaged by AFM. This is also consistent with the results of mechanical tests (dynamic shear rheometer) on the same materials. Finally a design formula is proposed that relates the blending zone dimension to temperature and mixing time. This relation would bring the results of this study from small length scales up to the engineering level.
  Authors: Nahar, Sayeda Nowrozon; Mohajeri, Mohamad; Schmets, Alexander J. M.; Scarpas, Athanasios; van de Ven, Martin F. C.; Schitter, Georg
  Authors: Nahar, Sayeda Nowrozon; Mohajeri, Mohamad; Schmets, Alexander J. M.; Scarpas, Athanasios; van de Ven, Martin F. C.; Schitter, Georg
  Year: 2013
  Document Type: Paper
  Subject: Materials; Pavements
  Session: 307
  Paper Number: 13-0763
• Accelerated Method to Evaluate Performance of Slag Used as Unbound Material in Road Bases
  Abstract: Because of environmental reasons, secondary materials will be and are being used on a large scale in road construction. Using these materials however is becoming a challenge because little information is available about their future behaviors and their performance is therefore difficult to estimate. In this study, aging is proposed as a means of exploring the long-term mechanical and physical performance of secondary materials. A slag mixture which is routinely used in the Netherlands in road (sub-)bases was selected as a reference material. The A32 motorway in the Netherlands was used as a source of field aged granulated Blast Furnace Slag (BFS) materials. The base layer of this motorway suddenly experienced serious failure after 20 years. In order to prevent similar problems to occur an aging method is suggested to detect at an early stage potential poor material performance. Three aging approaches including freeze-thaw (FT) action, steam aging and normal aging were chosen and applied to fresh and the field aged materials. These treatments have affected material characteristics. The results show that there is a linkage between secondary material performance and temperature, moisture and time.Response behavior for the steam aged laboratory samples and the A32 base material are similar, suggesting that the steam aging method did a reasonable job of producing a material of similar distress. The microstructural analysis suggests that it is possible to trace the chemical components which may attribute to the failure process of slag materials.
  Authors: Akbarnejad, Sadegh; Houben, Lambert; Molenaar, André
  Authors: Akbarnejad, Sadegh; Houben, Lambert; Molenaar, André
  Year: 2013
  Document Type: Paper
  Subject: Geotechnology; Materials; Pavements
  Session: 293
  Paper Number: 13-0804
• Application of Steam Aging Method for Evaluation of Slag System as a Granular Material
  Abstract: Long term performance of secondary materials is becoming a challenging aspect in road construction since due to their benefits they are being used on a large scale, but on the other hand their future behavior is difficult to estimate. Therefore, there is need for an accelerated test protocol that allows to estimate the potential loss of strength of such materials as well as their potential volumetric change. A research program was therefore carried out to investigate the effects of steam aging on the performance of slag mixtures.Different slag mixtures which are routinely used in the Netherlands in road (sub-)bases were selected. A motorway in the Netherlands was used as a source of field aged materials. The base layer of this motorway experienced serious failures. In order to prevent similar problems a steam aging method was suggested to detect at an early stage material with potential poor performance.The results showed that certain mixtures may expand during steam aging and the compressive strength of these mixtures increased during 7 days steam aging, afterwards it decreased. The microprobe technique was adopted to measure the corresponding chemical composition and monitor the micro-structural changes.It was found that the reactivity of slag materials is influenced by the chemical composition and the aging time. The measured data have indicated a relationship between some major chemical compositions and mechanical properties of the slags. Empirical equations were developed to estimate the influence of chemical composition on the compressive strength and volume expansion.
  Authors: Akbarnejad, Sadegh; Houben, Lambert; Molenaar, André
  Authors: Akbarnejad, Sadegh; Houben, Lambert; Molenaar, André
  Year: 2013
  Document Type: Paper
  Subject: Geotechnology; Materials; Pavements
  Session: 293
  Paper Number: 13-0808
• Analysis of Five-Point Bending Test for Multilayer Surfacing System on Orthotropic Steel Bridges
  Abstract: Light weight orthotropic steel deck bridges have been widely utilized in long span bridges, movable bridges and bridges in seismic zones. In the Netherlands a surfacing structure for orthotropic steel bridge decks mostly consists of five structural layers: top porous asphalt layer, guss asphalt layer, steel deck and two membrane layers.The French five-point bending test (5PBT) provides a laboratory scale test that allows studying the fatigue resistance of surfacing systems on orthotropic bridge decks (OBD). In this paper, an analytical solution for 5PBT setup is presented. In order to better understand the influence of geometrical, mechanical and structural parameters on the performance of the whole surfacing structure, a parametric study is performed at the numerical platform CAPA-3D that developed at the Section of Structural Mechanics of TU Delft. The thicknesses of the top porous asphalt layer, middle guss asphalt layer and the steel plate are varied. The Influences of the mechanical properties of both membrane layers are investigated. The sensibilities of those factors are evaluated by the examination of the maximum tensile stress at porous asphalt layers and the strain distributions at three cross sections.
  Authors: Li, Jinlong
  Authors: Li, Jinlong
  Year: 2013
  Document Type: Paper
  Subject: Bridges and Other Structures; Materials
  Session: 651
  Paper Number: 13-0815
• Durability Quantification for TiO2 Photocatalytic Concrete and Asphalt Pavements
  Abstract: The use of nano sized titanium dioxide in photocatalytic pavements to combat air pollution has received considerable attention in recent years. Past research focused on the effects of environmental and operational parameters on photocatalytic efficiency and its performance under laboratory and field conditions. Few studies have attempted to quantify the durability of the technology integrated with in-service photocatalytic pavements. This study developed and implemented a new photocatalytic quantification method used to quantify the short term durability of a TiO2 spray application on two pavement surfaces: concrete and asphalt. This was accomplished through developing a nitrate extraction method that could be used on in-service pavements without requiring core extraction. Results of the proposed method were compared to results obtained from the Japanese Industrial Standards: JIS R 1701-1. The experimental program included testing photocatalytic samples in the laboratory for NOx reduction and nitrate accumulation based on JIS R 1701-1. Results were compared to the nitrate accumulation using the proposed method and a correction factor was developed. The developed method was then used to quantify the durability of a TiO2 treated photocatalytic pavement over a five-month monitoring period under field conditions. Results showed that the durability of TiO2 in concrete and asphalt pavements is predicted to be 10 and 14 months, respectively.
  Authors: Osborn, David; Hassan, Marwa M.; Asadi, Somayeh; White, John R
  Authors: Osborn, David; Hassan, Marwa M.; Asadi, Somayeh; White, John R
  Year: 2013
  Document Type: Paper
  Subject: Environment; Materials; Pavements
  Session: 292
  Paper Number: 13-0901
• Viscoelastic-Viscoplastic Characterization of Unbound Granular Materials
  Abstract: The mechanical behavior of unbound granular materials had proven to be extremely challenging. In the pavement field, as well as in other geotechnical disciplines, these materials are usually treated as elastic or elasto-plastic. The objective of this work is to explore the applicability and potential for a viscoelastic-viscoplastic constitutive theory to characterize unbound granular materials. Such a theory contains as special cases the commonly applied behavior types, it is capable of modeling time-dependence, and can be further compounded to simulate sophisticated effects such as: anisotropy, damage, stiffening in compression, thermal sensitivity, and aging. Laboratory investigation is presented, in which a compacted granular specimen was exposed to a sequence of unidirectional creep and recovery cycles while under constant confinement conditions. Such a testing protocol offers an almost ‘automatic’ separation of the behavior into resilient (viscoelastic) and permanent (viscoplastic) components. Related experimental issues and data preprocessing elements are described in detail. From the measurements it was observed that the material creeps under load and exhibits partial, time-dependent recovery upon unloading. A one-dimensional viscoelastic-viscoplastic constitutive theory was applied as a first attempt to reproduce this behavior. The model was able to simulate very well the observed data trends and magnitudes, and hence deemed potentially generalizable to more advanced conditions.
  Authors: Levenberg, Eyal
  Authors: Levenberg, Eyal
  Year: 2013
  Document Type: Paper
  Subject: Geotechnology; Materials; Pavements
  Session: 293
  Paper Number: 13-0903
• Using Artificial Intelligence Models to Evaluate Field Performance of Photocatalytic Asphalt Pavement for Ambient Air Purification
  Abstract: In recent years, the application of titanium dioxide (TiO2) as a photocatalyst in asphalt pavement has received considerable attention due to its ability to purify ambient air from traffic-emitted pollutants via photocatalytic processes. The objective of this study was to utilize Artificial Neural Network (ANN) and Neuro-Fuzzy (NF) models to predict NOx concentration in the air as a function of traffic count (Tr) and climatic conditions including humidity (H), temperature (T), solar radiation (S), and wind speed (W) before and after the application of TiO2 on the pavement surface. A field study was conducted where a water-soluble nano TiO2 solution was sprayed on a 0.2 mile of asphalt pavement in Baton Rouge, LA. Two Artificial Intelligence (AI) models were developed to predict NOx concentrations before and after TiO2 application. Results showed that the NF model provided a better fitting to NOx measurements than the ANN model in the training, validation, and test steps. Results of a parametric study showed that traffic level, relative humidity, and solar radiation had the most effects on photocatalytic efficiency. In addition, the increase in wind speed and relative humidity negatively affected the effectiveness of NOx reduction efficiency. However, the increase in UV light intensity improved NOx removal efficiency of the surface coating.
  Authors: Asadi, Somayeh; Hassan, Marwa M.; Nadiri, Ataallah; Mohammad, Louay N.
  Authors: Asadi, Somayeh; Hassan, Marwa M.; Nadiri, Ataallah; Mohammad, Louay N.
  Year: 2013
  Document Type: Paper
  Subject: Environment; Materials; Pavements
  Session: 292
  Paper Number: 13-0918
• Mechanical Property Characterization of Warm-Mix Asphalt Prepared with Chemical Additives
  Abstract: This study experimentally characterized the mechanical properties of warm-mix asphalt (WMA) prepared with two chemical additives: EvothermTM 3G and Rediset® LQ-1106, using laboratory-mixed and laboratory-compacted (LMLC) specimens. A conventional stone matrix asphalt (SMA), widely used in expressway overlay projects in the Chicago area, was selected as the control mixture. Two warm SMA mixtures were prepared by adding 0.5% EvothermTM 3G and 0.5% Rediset® LQ-1106 by weight of binder, respectively. The performances of the control SMA, EvothermTM SMA, and Rediset® SMA were evaluated and compared through extensive laboratory testing, including complex modulus, loading wheel track, indirect tension, and semi-circular beam at various curing time periods after compaction. This study concluded that the two warm SMA mixtures performed comparably to the control SMA with regards to the complex modulus, potential rutting resistance, tensile strength, and potential fracture resistance. Both warm SMA mixtures provided slightly lower tensile strengths and complex moduli than the control SMA. The rutting and fracture resistance potential of the two warm SMA mixtures was relatively similar to that of the control SMA. The curing time effect on the performance of the two warm SMA mixtures varied depending on the material property measured as well as the additive type. However, a strong correlation between strength gaining and curing time for the two warm SMA mixtures could not be concluded.
  Authors: Leng, Zhen; Gamez, Angeli; Al-Qadi, Imad L.
  Authors: Leng, Zhen; Gamez, Angeli; Al-Qadi, Imad L.
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 597
  Paper Number: 13-0938
• Simplification of Linear Amplitude Sweep Test and Specification Parameters
  Abstract: The Linear Amplitude Sweep (LAS) test has recently been approved by AASHTO as a provisional standard, and is currently being considered for specification of asphalt binder fatigue resistance. The LAS test is a cyclic torsion test, conducted in the Dynamic Shear Rheometer (DSR) that uses increasing loading amplitudes to accelerate damage. The LAS test has being proposed as a surrogate to the time sweep (TS) test, which is a conventional fatigue test consisting of repeated cyclic loading at constant amplitude. The TS test is considered unsuitable for specification due to the uncertainty in the test duration required to induce and quantify fatigue. Recent ruggedness testing efforts have shown that the LAS test cannot be conducted by all DSRs. This study evaluates a simpler amplitude ramping procedure that resolved the difficulties with some rheometers. Additionally, a simple specification parameter is introduced to offer a practical approach to define damage tolerance. The definition of failure is based on a more recent study to explain the mechanisms of fatigue damage under TS testing in the DSR. Based on a comparison between TS and LAS test results, it is demonstrated that the damage evolution in the two tests differs, indicating the LAS test is very complex and is better referred to as a “damage tolerance” test rather than true fatigue test. Using the simplified analysis approach for the modified LAS procedure, a critical cracking length signifying the start of rapid crack growth is proposed for specification of binder damage tolerance at intermediate temperature.
  Authors: Hintz, Cassie A; Bahia, Hussain U.
  Authors: Hintz, Cassie A; Bahia, Hussain U.
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 604
  Paper Number: 13-0963
• Measurement of Pavement Solar Reflectivity and Effect on Thermal Performance
  Abstract: Solar reflectivity (or albedo) plays an important role in the thermal behavior of pavements and other ground surfaces, and their resultant impacts on humans and the environment. This study developed a new albedo measurement system with a dual-pyranometer and automatic data acquisition system, and used it to conduct field measurements of solar reflectivity on different pavement materials and for long-term monitoring of albedo. The albedo values were obtained for commonly used land cover materials including asphalt, concrete and block paver surfacing materials with different designs, which can help reduce the uncertainty in understanding, evaluating and modeling the thermal behavior and environmental impacts of ground surfaces with different albedos. This study found that the albedo of pavement materials is high in the early morning and late afternoon; it is low and constant over time in the mid-day. This suggests that albedo should be measured near mid-day, which is addressed in one of two standard test procedures reviewed. Clouds will negatively influence the value of measured albedo. No significant seasonal variation in albedo was found over one year. No impact of wind speed or air temperature on albedo is observed with the instrument used. An empirical relationship between the cooling effect of increased albedo on a pavement’s high temperature and solar radiation was developed. The cooling effect has a positive correlation with the peak solar radiation intensity. This empirical relationship can be used to roughly estimate the cooling effect of increased albedo or heating effect of reduced albedo on pavement for various climates and seasons with different solar radiation intensities.
  Authors: Li, Hui; Harvey, John; Kendall, Alissa
  Authors: Li, Hui; Harvey, John; Kendall, Alissa
  Year: 2013
  Document Type: Paper
  Subject: Environment; Materials; Pavements
  Session: 292
  Paper Number: 13-1116
• Cooling Effect of Permeable Asphalt Pavement Under Both Dry and Wet Conditions
  Abstract: The improvement of the street thermal environment for walking and cycling is attracting increased attention as a strategy for increasing livability. This approach has also been proposed as a strategy for mitigating the local heat island effect and reducing energy use for buildings and vehicle air conditioning during hot periods. This research explored a potential pavement design and management strategy that potentially could be used for improving the street thermal environment and mitigating heat islands. Through field measurements on pavement test sections with both conventional and alternative designs, the thermal behavior and cooling effect of permeable asphalt pavements under both dry and wet condition were investigated. The overall 7-day average cooling effect of wetting once on permeable pavements for near-surface air is approximately 0.2 to 0.45°C; for the surface it is approximately 1.2 to 1.6°C; and approximately 1.5 to 3.4°C for the in-depth layers. Based on the findings, permeable asphalt pavements have the potential of being a type of cool pavements which produces lower temperatures and thus helps improve the thermal environment and mitigate the heat island effect. However, attention should be given to this type of pavements under dry conditions. As a pavement thermal management strategy, water from rain or irrigation systems might need to be applied to the pavements to produce a better cooling effect for improving the thermal environment and mitigating the heat island.
  Authors: Li, Hui; Harvey, John; Jones, David
  Authors: Li, Hui; Harvey, John; Jones, David
  Year: 2013
  Document Type: Paper
  Subject: Environment; Materials; Pavements
  Session: 292
  Paper Number: 13-1115
• Evaluation of Microencapsulation of Dicyclopentadine and Sodium Silicate for Self-Healing Concrete
  Abstract: Considerable interests have been given in recent years to utilize self-healing materials in concrete. The concept of microcapsule healing is based on a healing agent being encapsulated and embedded in the concrete. The objective of this study was to evaluate the effects of preparation parameters, namely, temperature, agitation rate, and pH on the shell thickness and size (diameter) of the microcapsules. Two healing agents were evaluated in this study, dicyclopentadiene (DCDP) and sodium silicate. Based on the results of the experimental program, it was determined that as the pH was reduced, the shell thickness increased for sodium silicate. Unlike DCDP, sodium silicate shell thickness was almost twice the amount of DCDP. The more uniform and coherent microcapsules were produced at a temperature of 55°C. For the DCDP microcapsules and at 49°C, the solution remained an emulsion and no encapsulation took place. The increase in agitation rate resulted in a decrease in the average diameter of the microcapsules for DCDP. This is due to the large microcapsules being broken up into smaller ones when high shear is applied. On the other hand, the diameter of the microcapsules remained constant for sodium silicate microencapsulation as the agitation rate increased. Testing of concrete specimens modified with the two healing agents showed that DCDP-based microcapsules were effective in enhancing the modulus of elasticity of un-cracked concrete and increasing its modulus of elasticity after healing. For sodium silicate, an optimum pH value should be identified in order to produce microcapsules that enhance the modulus of elasticity of concrete before and after healing.
  Authors: Gilford III, James; Hassan, Marwa M.; Rupnow, Tyson; Barbato, Michele; Okeil, Ayman M.
  Authors: Gilford III, James; Hassan, Marwa M.; Rupnow, Tyson; Barbato, Michele; Okeil, Ayman M.
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 288
  Paper Number: 13-1172
• Influential Depth by Water Absorption and Surface Drying in Concrete Slabs
  Abstract: Water is one of the major factors that contribute to deformation and deterioration of concrete structures. For structures such as slabs or pavements on ground, the top surface can be subject to drying and bottom surface can be in contact with water due to ineffective drainage. The knowledge of moisture distribution and influential depth in slabs is of considerable significance for better durability prediction. This paper investigates the effects of surface drying, self-desiccation, and bottom water absorption on moisture profiles in concrete slab. It was found through experimental measurements and simulations that the influential depth is about 5 ~ 10 cm from external surface drying. The influential depth is greater for higher w/c concrete due to the greater diffusion coefficient. The influential depth from water absorption is relatively stable at about 5 cm, regardless of w/c. This is because the competing effects from sorptivity or hydraulic diffusivity and moisture content in concrete. The w/c, environment RH, and moisture transport properties of concrete are factors affecting moisture distribution in slabs. The shape of moisture profiles are closely related to w/c which causes different extent of self-desiccation. An equivalent temperature gradient can be used to quantify the moisture gradient effect. Given the environment conditions are the same, the analytical simulation suggests that greater results in high w/c concrete slab.
  Authors: Wei, Ya; Gao, Xiang; Hansen, Will
  Authors: Wei, Ya; Gao, Xiang; Hansen, Will
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 287
  Paper Number: 13-1297
• Thermomechanical Model to Study Impact of Internal Void Structure on Mechanical Performance of Asphalt Mixtures
  Abstract: This paper evaluates the impact of the internal air void structure of asphalt mixtures on the thermo-mechanical response of asphalt courses. A random field technique was used to stochastically generate probable air void distributions, replicating those observed in actual field cores. These spatial void distributions were later used to assign different thermal diffusion properties throughout the asphalt layer, and a thermal-diffusion process was simulated after implementing the model in finite elements. The pavement is also subjected to mechanical loading, and the viscoelastic material properties of the asphalt course change in space during the simulations according to both the air void content and the temperature throughout the layer. The main result from this study is that the quality of the compaction process, which is represented by the internal dispersion of the air voids, strongly impacts the uncertainty of the mechanical response of asphalt courses.
  Authors: Castillo, Daniel; Caro, Silvia
  Authors: Castillo, Daniel; Caro, Silvia
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 826
  Paper Number: 13-1420
• Effectiveness of Heavier Tack Coat on Field Performance of Open-Graded Friction Course
  Abstract: Compared to a conventional hot mix asphalt mixture, open-graded friction course (OGFC) is more prone to pavement distresses such as cracking and raveling, resulting in a shorter service life. One way to potentially improve the performance of OGFC is to enhance the interface bond between the OGFC and the underlying layer by applying a heavier tack coat. The study presented in this paper was designed to evaluate the effectiveness of using a heavier tack coat on the field performance of OGFC by comparing the field performance of the same OGFC mixture placed in Sections N1 and N2 on the NCAT Pavement Test Track. In Section N1, a heavier polymer-modified tack coat was applied using a spray paver right before the OGFC layer was placed. In Section N2, a trackless tack was applied at a regular application rate using a distributor truck. The sections were trafficked to 10 million equivalent single axle loads by a fleet of heavy trucks for two years. Field performance of these two sections was monitored on a weekly basis. The field performance characteristics measured include pavement stiffness, pavement structural response, surface functional characteristics, and pavement distresses. The results of this study showed that the OGFC layer in Section N1 in which a heavier tack coat was applied performed better than that of Section N2 in which a conventional tack coat was used. It is recommended that a heavier tack coat be used to improve the performance of OGFC surfaces.
  Authors: Tran, Nam; Timm, David H.; Powell, Raymond Lee; Sholar, Gregory Allen; Willis, James Richard
  Authors: Tran, Nam; Timm, David H.; Powell, Raymond Lee; Sholar, Gregory Allen; Willis, James Richard
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 655
  Paper Number: 13-1431
• Evaluation of Rejuvenator's Effectiveness with Conventional Mix Testing for 100% RAP Mixtures
  Abstract: This paper presents research evaluating effectiveness of rejuvenators for production of very high (40-100%) Reclaimed Asphalt pavement (RAP) content mixtures. Nine differently originated softening agents were tested, including plant oils, waste derived oils, engineered products, as well as traditional and non-traditional refinery base oils. Two different dosages of the agents were added to binder extracted from RAP to evaluate their softening potential through testing of kinematic viscosity and penetration at two different temperatures. At 25°C the softening efficiency varied by a factor of twelve between the most and least effective rejuvenators. Consistency results at different temperatures were used to express temperature susceptibility by means of Penetration Index (PI), Penetration-Viscosity Number (PVN) and Bitumen Test Data Chart (BTDC) of the softened binders. The PI results varied measurably depending on the rejuvenator and supported the low temperature mixture test results, showing that PI may be a good and simple measure of rejuvenation effectiveness. Low temperature mixture embrittlement was evaluated at -10°C through determination of the indirect tensile strength and creep compliance for rejuvenated 100% RAP mixture samples. It can be concluded that four of the nine tested rejuvenators reduced extracted binder consistency to the necessary level and reduced susceptibility of RAP mixtures to low temperature embrittlement. Of the four, two engineered products tested had notably different performance but neither was superior to similar generic oils.
  Authors: Zaumanis, Martins; Mallick, Rajib B.; Frank, Robert
  Authors: Zaumanis, Martins; Mallick, Rajib B.; Frank, Robert
  Year: 2013
  Document Type: Paper
  Subject: Materials; Pavements
  Session: 307
  Paper Number: 13-1447
• Determination of Bulk Volume of Asphalt Specimens with Image-Based Modeling
  Abstract: An approach is explored for modernizing the determination of bulk density of compacted asphalt specimens. It is based on calculating the bulk volume of the specimen in a three-dimensional model reconstructed from its images. The paper presents the basics of image-based modeling, founded upon the science of photogrammetry and computer vision. Next, a demonstrative application is described, in which a field core is photographed from many viewpoints with a consumer grade camera, and the images are combined into a sparse point cloud. This cloud is subsequently ‘meshed’ with planar polygons into a closed 3D shape and its volume calculated. It was found that the model-core volume was very close to that measured with a traditional liquid-displacement approach. It was also found that while the volume was relatively insensitive to the quantity and quality of the images used for the reconstruction, the computational time varied significantly from minutes to hours. Based on the favorable findings of this limited application, the approach is deemed promising and viable, worthy of more in-depth examination.
  Authors: Levenberg, Eyal; Manevich, Alex
  Authors: Levenberg, Eyal; Manevich, Alex
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 826
  Paper Number: 13-1758
• Estimation of Spacing and Width of Shrinkage Cracks in a Road Base with Cement-Treated Recycled Demolition Waste
  Abstract: In this paper a simplified mechanical method for estimating the shrinkage crack spacing and width in a base layer is presented. The base material is cement treated mix granulate produced by using recycled crushed concrete and masonry aggregates (CTMiGr). This method is based on material properties of CTMiGr as measured in the laboratory and the average climatic conditions recorded in the Netherlands. The calculated crack pattern showed to be comparable to the crack spacing observed in the field. The masonry content is a key factor determining the shrinkage crack characteristics. With increasing the masonry content, the crack spacing becomes larger and the width of the primary cracks dramatically decreases. Compared to the effect of the cement content and the moisture content on the shrinkage crack pattern, the influence of the degree of compaction is less.
  Authors: Xuan, Dongxing; Houben, Lambert; Molenaar, André
  Authors: Xuan, Dongxing; Houben, Lambert; Molenaar, André
  Year: 2013
  Document Type: Paper
  Subject: Geotechnology; Materials
  Session: 746
  Paper Number: 13-1494
• Phase Field Modeling of Mode I Cracking Failure in Asphalt Binder
  Abstract: Cracking failure in asphalt binder in winter has always been one of the most serious problems in pavement structures. Classical fracture mechanics is the most widely used method to analyze the initiation and propagation of cracks. In this paper, a new modeling and computational tool, namely, the phase-field method is proposed for modeling the Mode I cracking failure in asphalt binder. This method describes the microstructure using a phase-field variable which assumes one in the intact solid and negative one in the crack region. The fracture toughness is modeled as the surface energy stored in the diffuse interface between the intact solid and crack void. To account for the growth of cracks, a non-conserved Allen-Cahn equation is adopted to evolve the phase-field variable. The energy based formulation of the phase-field method handles the competition between the growth of surface energy and release of elastic energy in a natural way: the crack propagation is a result of the energy minimization in the direction of the steepest descent. Both the linear elasticity and phase-field equation are solved in a unified finite element frame work, which is implemented in the commercial software COMSOL. The mode I crack simulation is performed for validation. It was discovered that the onset of crack propagation agrees very well with the Griffith criterion and experimental results.
  Authors: Hou, Yue; Yue, Pengtao; Wang, Linbing; Sun, Wenjuan; Pauli, Adam Troy; Wang, Dong; Zhou, Wenhuan; Hu, Mingfang
  Authors: Hou, Yue; Yue, Pengtao; Wang, Linbing; Sun, Wenjuan; Pauli, Adam Troy; Wang, Dong; Zhou, Wenhuan; Hu, Mingfang
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 604
  Paper Number: 13-1554
• Full Seismic Waveform Tomography at a Highly Variable Florida Site
  Abstract: The paper presents the application of 2-D time-domain waveform tomography to a highly variable site in Florida. The measured seismic surface wave fields were inverted using a full waveform inversion technique, based on a finite-difference solution with Gauss-Newton updating. Both the compression wave (P-wave) and shear wave (S-wave) velocities are inverted independently and simultaneously for possible indications of soil types. The waveform analysis was able to delineate: (1) a shallow low-velocity layer, (2) a variable high-velocity layer, (3) a low-velocity zone embedded at 9 to 14 m depth, and (4) highly variable bedrock, laterally and vertically, at the bottom of profile. The computed shear wave velocities with depth were found to be generally consistent with cone penetration test (CPT) tip resistance. The technology is very applicable to both shallow and deep foundation design where soil stratigraphy as well as variability (horizontal and vertical) is important. Moreover, the invasive soundings (e.g. CPT, SPT) could be used for assessing properties, and the seismic waveform tomography may then be used to assess layer boundaries and horizontal spatial correlation structure.
  Authors: Tran, Khiem T.
  Authors: Tran, Khiem T.
  Year: 2013
  Document Type: Paper
  Subject: Geotechnology; Materials
  Session: 291
  Paper Number: 13-1520
• Laboratory Study of Fly Ash and Soil Mixtures for Sustainable Roadway Embankments
  Abstract: This paper describes a laboratory study for the mechanical properties and environmental suitability of mixing an off-specification type of fly ash with soil for roadway embankment/structural fill constructions. Fly ash has a potential to be beneficially used in roadway constructions, including embankments and pavement structural layers such as base/sub-base layers, shoulders, asphalt concrete, and Portland cement concrete, to create longer lasting and sustainable infrastructure. The study includes the optimization of the mixing ratio of fly ash and soil and the leaching potential of heavy metals in the fly ash for environmental impact assessment. The fly ash was collected from a utility power plant in Mississippi and local soil was used. The specimens compacted at various fly ash-soil ratios and water contents were tested for compaction properties, unconfined compressive strength (UCS), and direct shear tests. Results showed that the addition of fly ash into soil resulted in appreciable increases in the UCS and shear strength of the clay soil. After 14 days of curing, the UCS of the samples compacted from the fly ash-soil mixtures ranged between 940 kPa and 4300 kPa, whereas the soil alone had a UCS of 317 kPa. Friction angle increased by 2-3 times for different fly ash-soil mixtures. An optimum mixing ratio of 60% fly ash and 40% soil is recommended. Leaching of trace metals from the fly ash-soil mixtures were tested through batch leaching tests and column leaching test. The batch leaching test results show that the concentrations of the eight environmentally concerned metals in the leachates are all below the U.S. EPA regulatory levels for hazardous waste and the Mississippi Department of Environmental Quality regulation standards for beneficial use of fly ash. The column leach test results show that only Chromium and Barium are detectable in the effluent and are in very low concentrations.
  Authors: Li, Lin; Li, Yadong
  Authors: Li, Lin; Li, Yadong
  Year: 2013
  Document Type: Paper
  Subject: Geotechnology; Materials
  Session: 746
  Paper Number: 13-1576
• Constitutive Modeling of Fatigue Damage Response of Asphalt Concrete Materials
  Abstract: The fatigue damage response of asphalt concrete is modeled by proposing a damage evolution function in the context of continuum damage-healing mechanics (CDHM). The uniaxial constant strain rate test is used to experimentally identify the damage density during this test. The identified damage density is used to propose the form for the evolution of the damage density variable. It is also shown that the accurate prediction of the fatigue life of asphalt concrete requires the incorporation of the micro-damage healing effect. It is argued that the micro-damage healing can also occur during the cyclic strain controlled tests in tension. The proposed damage model is incorporated in the PANDA model that includes the Schapery’s viscoelastic model (VE), Perzyna’s viscoplastic model (VP), and the micro-damage healing model (15) (H) to simulate the fatigue damage response of asphalt concrete. The damage model is validated against an extensive experimental data including constant strain rate, cyclic displacement controlled, and cyclic stress controlled tests over a range of temperatures, strain rates, loading frequencies, and stress/strain levels/amplitudes. Model predictions show that the proposed damage model is capable of predicting the fatigue damage response of asphalt concrete subjected to different loading conditions.
  Authors: Darabi, Masoud K.; Abu Al-Rub, Rashid K.; Masad, Eyad A.; Little, Dallas N.
  Authors: Darabi, Masoud K.; Abu Al-Rub, Rashid K.; Masad, Eyad A.; Little, Dallas N.
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 653
  Paper Number: 13-1598
• Limit Analysis for Historic Masonry Bridge with CFRP Reinforcements
  Abstract: This paper deals with the collapse behavior of a historical masonry arch bridge subject to combined seismic loads, by means of the limit analysis and shakedown theorems. A finite element modal analysis and seismic load evaluation was performed building a program code. The assessment of the collapse loads and shakedown multiplier, consisting of corresponding nonlinear constrained optimization problems, were analyzed using lower bound theorems of the limit analysis and shakedown theory, respectively. Because the retrofitting of this structure cannot be performed in the intrados surface, the application of CFRP strips on the extrados of the arch is a useful and valuable technique, as shown by a significant increase of the limit and shakedown multipliers.
  Authors: Gesualdo, Antonio; Catalani, Giulio
  Authors: Gesualdo, Antonio; Catalani, Giulio
  Year: 2013
  Document Type: Paper
  Subject: Bridges and Other Structures; Design; Materials
  Session: 300
  Paper Number: 13-1658
• Quality and Durability of Warm Rubberized Asphalt Cement in Ontario
  Abstract: This paper documents and discusses an investigation of performance-based testing of asphalt cement (AC), AC modified with warm mix technology additives (warm AC), rubberized asphalt cement (RAC), and warm RAC. A number of control, warm, and RAC binders from Ontario construction contracts were investigated for their compliance with conventional Superpave™ as well as additional specification criteria. It was found that all samples passed the Superpave requirements but only one satisfied the additional Ontario criteria. One warm AC and two field-blended RAC samples showed high levels of physical hardening which can lead to early cracking. The warm AC lost 8°C when stored isothermally for three days at low temperatures according to Ontario’s extended bending beam rheometer (BBR) protocol (LS-308). The two RAC samples lost 10°C and 12°C following the same conditioning. Many of the investigated samples showed deficient strain tolerance as measured in Ontario’s double-edge-notched tension (DENT) test (LS-299).In an effort to formulate warm RAC with improved properties, a number of compositions were prepared with soft Cold Lake AC and a small quantity of naphthenic oil. These binders showed little chemical and physical hardening and reasonable critical crack tip opening displacements (CTOD). Strain tolerance was much improved by co-blending with a high vinyl type styrene-butadiene-styrene (SBS) polymer and a small amount of sulfur. The Ontario Ministry of Transportation is interested in using the developed formulations in future pavement trials with expected improvements in pavement performance.
  Authors: Xu, Hattie; McIntyre, Andrew; Adhikari, Tham; Hesp, Simon; Marks, Pamela; Tabib, Seyed
  Authors: Xu, Hattie; McIntyre, Andrew; Adhikari, Tham; Hesp, Simon; Marks, Pamela; Tabib, Seyed
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 596
  Paper Number: 13-1678
• Coniferyl-Alcohol Lignin as Antioxidant of Petroleum Asphalt: Quantum Chemistry-Based Atomistic Study
  Abstract: Petroleum asphalt is an important base material in many industrial applications, such as the main binding and waterproofing component in road pavements and roof shingles. Being an organic end product of petroleum serving under the general open-to-air conditions, asphalt can lose the desired rheological properties with time due to oxidative hardening or aging that frequently leads to increase in viscosity, separation of components, and loss of cohesion and adhesion, and thereby becomes hardened. A common practice to alleviate asphalt aging today is using different chemical additives or modifiers as antioxidants. The current state of knowledge in asphalt oxidation and antioxidant evaluation is focused on monitoring the degradation in asphalt’s physical properties, mainly the viscosity and ductility, which although satisfying direct engineering needs does not contribute to the fundamental understanding of the aging and anti-aging mechanisms. Within this context, this study was initiated to study the anti-oxidation mechanisms of bio-based additives, using the coniferyl-alcohol lignin as an example, by developing a quantum chemistry based chemophysical environment in which the various chemical reactions among asphalt components, anti-oxidative additive and oxygen, as well as the incurred physical changes can be studied. The techniques of X-ray photoelectron spectroscopy (XPS) was used to prove the validity of the modified and unmodified asphalt models, from which the XPS results showed high agreement to the model predictions.
  Authors: Pan, Tongyan
  Authors: Pan, Tongyan
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 596
  Paper Number: 13-1805
• Recycled Asphalt Shingle Binder Characterization and Blending with Virgin Binders
  Abstract: In addition to reclaimed asphalt pavement (RAP), recycled asphalt shingles (RAS) has been fairly used by asphalt paving industry in recent years. However, very limited information on RAS binder characterization and blending with virgin (and RAP) binders is available in the literature partially due to the limitations of regular dynamic shear rheometers (DSR) and bending beam rheometer (BBR) to test this type of materials. This paper first validated the applicability of the existing asphalt binder extraction and recovery procedures to extremely stiff RAS binders through comparing the binder properties before and after the extraction and recovery processes. Then a variety of tear-off asphalt shingles (TOAS) and manufacture waste asphalt shingles (MWAS) were extracted, recovered, and characterized using a high temperature DSR and a BBR. It was found that TOAS binders with an average of high temperature grade of 175 °C were much stiffer than MWAS binders which have an average of high temperature grade of 131 °C. Furthermore, this paper investigated the blending among virgin/RAP/RAS binders. The results indicated that the virgin/RAS binders blending didn’t follow the linear blending chart as the virgin/RAP binders blending often did. However, for practical applications, the linear blending chart can still be used for estimating continuous grade (high and low temperatures) of both virgin/RAS blended binders and virgin/RAP/RAS blended binders, if the RAS binder is limited within 30 % of the total binder. The applicability of the linear blending chart for virgin/RAP/RAS binders significantly reduces the DSR/BBR testing workload. Additionally, compared with TOAS binders, MWAS binders have much less impact on properties of the blended virgin/RAS binders. The significant differences between TOAS and MWAS, in terms of RAS binder properties alone and the blending characteristics of the virgin/RAS binders, imply that it is necessary to differentiate MWAS from TOAS in the mix design process and to have different upper limits on maximum binder replacement allowed for MWAS and TOAS.
  Authors: Zhou, Fujie; Li, Hongsheng; Lee, Robert E.; Scullion, Tom; Claros, German J.
  Authors: Zhou, Fujie; Li, Hongsheng; Lee, Robert E.; Scullion, Tom; Claros, German J.
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 596
  Paper Number: 13-1810
• Mechanistic Modeling of Fracture in Asphalt Mixtures Under Compressive Loading
  Abstract: When an asphalt mixture is subjected to a destructive compressive load, it experiences the primary, secondary and tertiary deformation stages. Studies in the literature focused on the plastic deformation in the primary and secondary stages, such as the prediction of flow number, which is the initiation of the tertiary stage. However, little effort has been reported on the mechanistic modeling of the damage that occurs in the tertiary stage. The objective of this study is to mechanistically characterize the damage in the tertiary stage. The preliminary study illustrated that the deformation during the tertiary flow was principally caused by the growth of cracks which was signaled by the increase of the phase angle. The strain caused by the crack growth is the viscofracture strain which can be obtained by performing strain decomposition in the destructive compressive test. The viscofracture strain is employed in this study to mechanistically characterize the time dependent fracture (viscofracture) of asphalt mixtures in compression. By using dissipated pseudo strain energy balance principle, damage density and true stress are determined and both increase with load cycles in the tertiary stage. The increased true stress yields extra viscoplastic strain, which is the reason why the permanent deformation is accelerated by the occurrence of the cracks. To characterize the evolution of the viscofracture, a pseudo J-integral Paris’ law in terms of damage density is proposed and the material constants in the Paris’ law are determined, which can be employed to predict the fracture of asphalt mixtures in compression.
  Authors: Zhang, Yuqing; Luo, Rong; Lytton, Robert Leonard
  Authors: Zhang, Yuqing; Luo, Rong; Lytton, Robert Leonard
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 599
  Paper Number: 13-1824
• Fracture Resistance of Warm-Mix Asphalt Concretes at Low Temperatures
  Abstract: The fracture resistance of WMA concrete was examined at low temperatures in co The fracture resistance of WMA concrete was examined at low temperatures in comparison with HMA. Three WMA additives (Evotherm, Pewo and Sasobit), two polymers (LVM and SBS), and one aggregate source were used to prepare 9 WMA mixtures and 3 HMA mixtures. The fracture toughness (KIC) was measured by a 3-point bending beam test at -5, -15, -20, -25 and -35¡É. All mixtures showed KIC increase by temperature decrease, making a peak at -15¡É or 20¡É, then decreased with further lowering temperatures due to differential thermal contraction. Most of WMA mixtures, showed higher KIC than HMA at severely low temperatures. It was found that the WMA mixtures were not more susceptible to brittle fractures than HMA at low temperatures, although they were produced at a relatively lower aggregate heating temperature.
  Authors: Lee, Sung-Jin; Park, Jiyong; Hong, Jun-Pyo; Kim, Kwang W.
  Authors: Lee, Sung-Jin; Park, Jiyong; Hong, Jun-Pyo; Kim, Kwang W.
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 597
  Paper Number: 13-1858
• PERFORMANCE OF FRP CONCRETE BEAMS EXPOSED TO SEVERE ENVIRONMENTS
  Abstract: The use of various forms of fiber reinforced polymers (FRP) has been on the increase in numerous construction applications. This includes internal reinforcement of Portland cement concrete by rods as well as strengthening concrete elements by laminates. However, there is little work conducted on concrete involving various combinations of FRP composites. Also, there is a need to better understand the behavior of FRP systems in concrete elements subjected to chemicals and to external heat. This study aims at investigating the flexural strength rendered by FRP rods and FRP external laminates mounted on concrete beams. Sets of beams were made with reinforcing steel, FRP rods and FRP laminates and were subjected to 3, 6 and 9 week cycles in fresh water, sea water and 20% magnesium sulphate as well as 6-hour exposure to temperatures of 80 and 150 0C. The flexural load was assessed for all beams prior to and after exposure cycles. The results of this work reveal that FRP smooth rods did not provide the anticipated reinforcement effect, likely due to a lack of bonding. The FRP laminates, however, contributed to a large increase in flexural strength particularly when used in conjunction with steel reinforcement. Sea water and 150 0C temperature caused the largest loss in flexural strength. It is recommended to use protective mortar layers to alleviate heat-induced loss of flexural strength. For future work, other sets of materials, FRP combination as well as exposure schemes need to be evaluated.
  Authors: Abou-Zeid, Mohamed Nagib; Agaiby, Michael G.; El-Deeb, Tarek; El-Said, Sherif; Georgy, Fadi; Zaki, Amr
  Authors: Abou-Zeid, Mohamed Nagib; Agaiby, Michael G.; El-Deeb, Tarek; El-Said, Sherif; Georgy, Fadi; Zaki, Amr
  Year: 2013
  Document Type: Paper
  Subject: Bridges and Other Structures; Design; Materials
  Session: 300
  Paper Number: 13-1833
• Measurement of Subgrade Thermal Conductivity Using a Modified Triaxial Test
  Abstract: This paper describes an approach to measure the thermal conductivity of Shelby tube samples of subgrade soil using a thermal needle embedded within a modified top platen of a triaxial cell. This approach permits quantification of the thermal conductivity of the subgrade soil under the in-situ stress state, as well as during isotropic compression. Although the impact of porosity on the thermal conductivity of soil has been studied extensively, the majority of these approaches involve compaction of several soil specimens at different water contents and densities, leading to different soil structures which may affect the thermal conductivity. To show how the impact of porosity could be obtained using a single specimen, an example test was performed on a compacted silt specimen. The thermal conductivity of the soil increased with decreasing porosity during loading, and decreased during unloading, albeit on a different path.
  Authors: McCartney, John Scott; Jensen, Erik; Counts, Brennan
  Authors: McCartney, John Scott; Jensen, Erik; Counts, Brennan
  Year: 2013
  Document Type: Paper
  Subject: Geotechnology; Materials
  Session: 696
  Paper Number: 13-1866
• Experimental Investigation of Chip Seal Adhesion Performance with Modified Binder in Cold Climate
  Abstract: The purpose of this study is to evaluate chip seal performance with neat and polymer modified bitumen chip seals constructed with different aggregate combinations with emphasis on aggregate retention under in climate using Accelerated Chip Seal Simulation Device (HSKSC). The aggregate retention performances of neat bitumen versus modified were compared with three types of aggregates at low temperatures. Major findings of this research include that polymer modification of neat bitumen improved aggregate retention performance. In addition, the results showed that decrease in temperature causes an increase in aggregate loss.
  Authors: Aktas, Bekir; Karasahin, Mustafa
  Authors: Aktas, Bekir; Karasahin, Mustafa
  Year: 2013
  Document Type: Paper
  Subject: Maintenance and Preservation; Materials; Pavements
  Session: 654
  Paper Number: 13-1916
• Laboratory Investigation of Self-Consolidating Concrete Containing Sustainable Technologies: Recycled Asphalt Pavements, Fly Ash, & Slag
  Abstract: The use of sustainable technologies such as supplementary cementitious materials (SCMs), and/or recycled materials is expected to adversely affect the performance of concrete mixtures. However, it is imperative to qualify and implement such mixtures in practice, if the required specifications of their intended application are met. This paper presents the results of a laboratory investigation of self-consolidating concrete (SCC) contacting sustainable technologies. Twelve mixes were prepared with different combinations of fly ash, slag, and Recycled Asphalt Pavement (RAP). Fresh and hardened concrete properties were measured, as expected the inclusion of the sustainable technologies affected both fresh and hardened concrete properties. Analysis of the experimental data indicated that inclusion of RAP not only reduces the ultimate strength, but it also affected the compressive strength development rate. The addition of RAP to mixes showed a consistent effect, with a drop in strength after 3, 14, and 28 days as the RAP content increased from 0 to 50%. However, most of the mixes satisfied SCC fresh properties requirements, including mixes with up to 50% RAP. Moreover, several mixes satisfied compressive strength requirement for pavements and bridges, those mixes included relatively high percentages of SCMs and RAP.  
  Authors: Mahmoud, Enad; Ibrahim, Ahmed; El-Chabib, Hassan; Patibandla, Varun
  Authors: Mahmoud, Enad; Ibrahim, Ahmed; El-Chabib, Hassan; Patibandla, Varun
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 290
  Paper Number: 13-1959
• Application of Semicircular Bend and Fénix Tests for Assessing Effect of Load Application Time and Temperature on Fracture Energy of Asphalt Mixtures
  Abstract: Significant progress to address this issue was made in a comprehensive research effort as part of two national pooled fund studies addressing low temperature cracking in the US. Two fracture methods were thoroughly investigated and were proposed for standardization: the Disc-Shaped Compact Tension DC(T) test and the Semi Circular Bend (SCB) test. Recently, a simpler test that combines the advantages of both DC(T) and SCB configurations has been developed and successfully used in Spain, the Fénix test. This paper presents the results from the application of SCB and Fénix tests in the assessment of fracture behavior of different types of mixtures and the effect of both loading rate and temperature have on the results obtained. The study was conducted jointly by the University of Minnesota (UM) and UPC- BarcelonaTech (UPC).
  Authors: Perez-Jimenez, Felix Edmundo; Botella Nieto, Ramon; Moon, Ki Hoon; Marasteanu, Mihai O.
  Authors: Perez-Jimenez, Felix Edmundo; Botella Nieto, Ramon; Moon, Ki Hoon; Marasteanu, Mihai O.
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 653
  Paper Number: 13-1979
• Experimental Study of Sustainable Asphalt: Influence of Thermochromic Materials
  Abstract: Asphalt pavements are widely used in highways due to their good performance and relatively low construction and maintenance costs. However, the black color of asphalt implies that the sunlight is not reflected but absorbed, which raises the temperature of the asphalt pavement and impairs its long-term durability. Thermochromic materials are substances that can reversibly change their colors in response to temperature. They reflect solar energy at high temperature and absorb that at low temperature. The innovation by this paper is to investigate the use of thermochromic materials in asphalt to develop thermochromic asphalt, which will reduce the surface temperature of asphalt pavement and lead to improved durability. Their thermochromic transition temperatures, which were characterized by Differential Scanning Calorimetry (DSC), range from 19.83 to 34.8 °C. The latent heats are between 1.74 and 3.59 J/g. The heat capacities measured with modulated DSC at 15, 25 and 35 °C are in the range of 1.392-1.724 J/(g•°C). Thermal conductivities were calculated in the range of 0.1478-0.2282 W/(m•°C). Both heat capacities and thermal conductivities at 25 °C are higher than those at other temperatures due to phase transition. The red and black asphalt show relatively higher heat capacities and thermal conductivities than the conventional pure asphalt. Comparison measurements found that the surface temperature of thermochromic asphalt can be significantly lower than that of the conventional pure asphalt with maximum decrease as high as 6.6 °C during summer. During winter and nocturnal in summer, the surface temperature of thermochromic asphalts are higher than that of the conventional pure asphalt, which helps to keep asphalt pavement warm and alleviates the problem of icing. The reduced surface temperature during summer and increased surface temperature during winter using thermochormic materials can be both desirable. For use as roof, for example, the use of thermochromic asphalt can lead to energy saving for air conditioning as high as 24%. This not only reduces the energy cost but also helps mitigate urban heat island and improve air quality and comfort.
  Authors: Hu, Jianying; Yu, Xiong
  Authors: Hu, Jianying; Yu, Xiong
  Year: 2013
  Document Type: Paper
  Subject: Environment; Materials; Pavements
  Session: 292
  Paper Number: 13-2029
• Significance of Mixture Parameters on Binder Aging in Hot-Mix Asphalt Mixtures
  Abstract: Traditionally, aging studies of asphalt materials have been conducted primarily on asphalt binders only, omitting any potential influence by the aggregate. These results are commonly extrapolated to the mixture behavior without a comprehensive understanding of how the mixture characteristics may potentially influence the aging of the binder within the mixture. This study was initiated by the FHWA to evaluate the effects of mixture parameters, namely different aggregate and asphalt binder sources, air voids, and binder contents on the aging characteristics of asphalt binders aged in mixtures. Those same binders were also aged in pressure aging vessel (PAV) pans in laboratory ovens to determine the aging characteristics of the asphalt binders, as is the current state of practice. These characteristics were determined by the binder kinetics, in terms of the carbonyl area (CA) measured from the Fourier Transform Infrared Spectroscopy spectra as a function of aging time and temperature. The hardening susceptibility (HS) of the asphalt binders as defined by the relationship between the low shear viscosity (LSV) and the carbonyl area was also determined. The HS relationships of the asphalt binders aged in the mixtures were compared to the HS of the binders aged in the PAV pans and were found to be statistically dissimilar for some mixtures and statistically similar for others. The analysis revealed that the effective binder content (Pbe) of the mixtures provided the strongest indicator as to whether or not the evaluated mixture parameters would have a significant influence on the aging characteristics of the asphalt binder.
  Authors: Morian, Nathan; Hajj, Elie Y; Sebaaly, Peter E.
  Authors: Morian, Nathan; Hajj, Elie Y; Sebaaly, Peter E.
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 670
  Paper Number: 13-2070
• Evaluation of Effect of Recycled Roof Membrane on Asphalt Mixture Performance Properties
  Abstract: ABSTRACTThis paper examines the effect of replacing part of the virgin binder with recycled roof membrane on the performance of hot mix asphalt mixtures with high percentages of recycled asphalt (RAP). The use of recycled roof membranes influences the asphalt mixture properties. In this study the influence of replacement of virgin binder by the binder in recycled roof membranes (GRM-50) on the performance properties of surface and base course asphalt mixtures with high RAP contents evaluated. Functional mixture properties like stiffness, fatigue and permanent deformation were determined to evaluate the performance. In addition to mixture properties also the properties of the recovered binders of these mixtures were determined. Both empirical and fundamental binder properties of the recovered binders were determined using penetration, ring and ball, and Dynamic Shear Rheometer (DSR) tests. The DSR results show that the recovered binder from mixtures containing recycled roof membrane (GRM-50) has significantly higher complex shear modulus G* values especially at high temperature (low frequency). They also show a lower phase angle d over a wide range of frequency and temperature compared to recovered binders from mixtures with only RAP. In line with the binder test results, the mixture tests clearly show that replacement of part of the virgin bitumen in the RAP mixture with recycled roof membrane increases the mixture dynamic stiffness, fatigue life and resistance to permanent deformation. With the Hirsch model it was verified if sufficient binder blending exists in the mixture, which is important in regard to durability.
  Authors: Merine, Girum Mengiste; Hagos, Eyassu Tesfamariam; van de Ven, Martin F. C.
  Authors: Merine, Girum Mengiste; Hagos, Eyassu Tesfamariam; van de Ven, Martin F. C.
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 743
  Paper Number: 13-2095
• Comparison of the Superpave Gyratory and Proctor Compaction Methods for the Design of Roller-Compacted Concrete Pavements
  Abstract: Roller-compacted concrete (RCC) is gaining popularity as a paving alternative for a number of roadway applications. RCC is a zero-slump concrete mixture that does not require forms, reinforcing, jointing or finishing. This type of material combines the advantages of conventional concrete pavements with the ease of construction of an asphalt pavement, and can be opened to traffic more quickly than conventional concrete pavements. The Superpave Gyratory Compactor was investigated as an alternative to Proctor compaction (ASTM D1557) for the design of RCC paving mixtures. Seventeen mix designs were generated, encompassing a range of aggregate sources, gradation types, and natural sand contents. In general, the Gyratory method did not produce equivalent designs to the Proctor method, such that the Gyratory method resulted in higher densities and lower optimum moisture contents. Also, gyratory compaction tended to generate a maximum, or ‘terminal’ achievable moisture content, regardless of the amount of moisture mixed in the specimen, and the corresponding densities continued to increase, rather than displaying the parabolic relationship typical of proctor compaction. The highest densities by both compaction methods tended to be achieved for blend gradations that most closely followed the maximum density line and included the greatest percentages of natural sand.
  Authors: Williams, Stacy Goad
  Authors: Williams, Stacy Goad
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 290
  Paper Number: 13-2110
• Assessment of Pavement Impacts due to Energy Developments in Texas
  Abstract: In recent years, Texas has experienced a boom in energy-related activities, particularly in wind power generation and extraction of oil and natural gas. While energy developments contribute to enhance the state¡¯s ability to produce energy reliably, many short-term and long-term impacts on the state¡¯s transportation infrastructure are not properly documented. Examples include the impact of frequent truckloads on state highway infrastructure such as pavement structures and shoulders, as well as impacts on roadside infrastructure such as driveways and drainage facilities. This paper describes the work to gauge the impact of increased level of energy-related activities on Texas Department of Transportation (TxDOT) pavements based on developing a geodatabase of energy developments in the state, field visits along with data collection, and assessment of remaining life of energy development impacted corridors that have been identified from this study. From this assessment, recommendations on road maintenance and repair were proposed to mitigate the impact of energy developments on Texas pavements.
  Authors: Oh, Jeong Ho; Fernando, Emmanuel G.; Quiroga, Cesar
  Authors: Oh, Jeong Ho; Fernando, Emmanuel G.; Quiroga, Cesar
  Year: 2013
  Document Type: Paper
  Subject: Maintenance and Preservation; Materials; Pavements
  Session: 808
  Paper Number: 13-2235
• Constitutive Modeling of Cyclic Viscoplastic Response of Asphalt Concrete
  Abstract: Rutting (i.e. permanent deformation) is the most important distress that asphalt concrete pavements are prone to at high temperatures. However, it is shown that the available classical viscoplastic theories are incapable of properly predicting the permanent deformation of asphalt concrete materials at high temperatures subjected to cyclic loading conditions. To remedy this issue, a physically-based viscoplastic hardening-relaxation model is proposed. This model considers the changes in the microstructure during the rest period. This evolution of the microstructure during the rest period causes the induced hardening stress to relax and recover which affects the viscoplastic properties of asphalt concrete before and after the rest period is applied. A memory surface is introduced as the general criterion for the evolution of the hardening-relaxation mechanism. The memory surface possesses a state variable memorizing the history of the viscoplastic deformation during the loading history. The proposed viscoplastic hardening-relaxation model is coupled to the Schapery’s viscoelastic model (VE) and classical Perzyna’s viscoplastic model (VP) and is validated against an extensive experimental data including repeated creep-recovery tests at different stress levels, confinements, loading times, and rest periods. It is shown that the proposed model reasonably predicts the cyclic viscoplastic response of asphalt concrete materials at high temperatures.
  Authors: Darabi, Masoud K.; Abu Al-Rub, Rashid K.; Masad, Eyad A.; Little, Dallas N.
  Authors: Darabi, Masoud K.; Abu Al-Rub, Rashid K.; Masad, Eyad A.; Little, Dallas N.
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 599
  Paper Number: 13-1839
• PROPERTIES OF PREPLACED AGGREGATE CONCRETE CAST IN AIR AND UNDER WATER
  Abstract: Producing good quality concrete requires proper placement and compaction during manufacturing. Among these known placement methods are in-air and preplaced aggregate concrete (PAC). PAC is a method in which coarse aggregate is first placed and compacted in the formworks and then cement mortar/grout is injected to fill the voids in between the coarse aggregates. However, there remains a need for a better understanding of the properties of such concrete when cast both in-air and underwater. Concrete mixtures were prepared at two w/c ratio of 0.35 and 0.45 and with two different coarse aggregates gradations. Specimens were prepared in air as well as at one meter depth underwater using gravity conventional method and preplaced aggregate method. Unit weight, air content and flow table tests were conducted for fresh concrete. Compressive strength (7 and 28-day), flexural strength, ultrasonic pulse velocity and shrinkage cracking tests were performed on the hardened concrete. Concrete slices were removed to assess the presence and distribution of coarse aggregates in concrete. The results reveal that PAC yields similar fresh concrete properties to the conventional concrete. PAC had higher compressive and flexural strength in particular with the w/c 0.45 mixtures. The PAC had better quality when pouring underwater as compared to free-fall concrete into water. These results were supported by visual examination as well as ultrasonic pulse velocity testing. Cracking was significantly less for all PAC concrete mixtures under investigation. Further studies, pilot investigations need to be performed to validate the findings of this work. Applicators should consider PAC as an alternative method in underwater concrete works.
  Authors: Abou-Zeid, Mohamed Nagib; Metawie, Ibrahim; El Deeb, Ahmed; Hosny, Amir; Khalifa, Mostafa; Youssef, Sameh; Assad, Minass
  Authors: Abou-Zeid, Mohamed Nagib; Metawie, Ibrahim; El Deeb, Ahmed; Hosny, Amir; Khalifa, Mostafa; Youssef, Sameh; Assad, Minass
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 290
  Paper Number: 13-1838
• Characterization of Mode-I and Mode-II Fracture Properties of Asphalt Mixture Using Semicircular Specimen Geometry
  Abstract: Cracking in asphalt pavements causes primary failure in the pavement structure and leads to long-term durability issues that are often related to moisture damage. The fracture resistance and characteristics of asphalt materials significantly affect the service life of asphalt pavements. Numerous studies to understand asphalt fracture in pavements have typically considered only mode-I (opening) fracture, but many observations have demonstrated the significance of mode-II (sliding) fracture for a better design of pavement structures and for damage characterization of asphaltic materials. This study presents experimental and numerical efforts to characterize the mode-I and mode-II fracture properties of an asphalt mixture. To this end, semi-circular bending tests were integrated with a digital image correlation system and an extended finite element method. The integrated experimental-numerical approach attempted here shows that the mode-II fracture property is approximately three times greater than the mode-I fracture property, which clearly indicates that the mode-dependent fracture characteristics are necessary in the structural design of asphalt pavements with which multiaxial damage is usually associated.
  Authors: Im, Soohyok; Ban, Hoki; Kim, Yong-Rak
  Authors: Im, Soohyok; Ban, Hoki; Kim, Yong-Rak
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 653
  Paper Number: 13-2289
• Revision and Further Validation of Surface-Performance Graded Specification for Surface Treatment Binders
  Abstract: The design and selection of surface treatment binders in service is currently based on specifications that only account for the penetration and ductility of emulsion residues or the penetration and viscosity of hot-applied asphalt cements. These specifications consider neither the entire range of temperatures that the binders may be subjected to during production and in service, nor long-term aging behavior. A surface performance-graded (SPG) specification for the selection of surface treatment binders, which takes into account the physical properties and performance of the binder at the temperature ranges in which the material will be used, was developed as part of previous Texas Department of Transportation (TxDOT) and National Cooperative Highway Research Program (NCHRP) projects. In the current study, the SPG specification was revised and further validated. This was accomplished by standardizing the emulsion residue recovery method through the evaluation of two warm oven methods, exploring the exclusive use of the dynamic shear rheometer (DSR) for determining performance-based properties, and further field validating the thresholds for these properties. The laboratory and field results were used to revise the SPG specification for surface treatment binders in service. Moreover, the results obtained from the multiple stress creep recovery and DSR frequency sweep tests were compared with field performance to evaluate additional criteria for the specification. This study is limited to producing a revised SPG specification for properties that address stiffness and aggregate retention in service; the effects of construction and quality control processes are beyond the scope of this study.
  Authors: Vijaykumar, Aishwarya; Martin, Amy Epps; Arambula, Edith
  Authors: Vijaykumar, Aishwarya; Martin, Amy Epps; Arambula, Edith
  Year: 2013
  Document Type: Paper
  Subject: Maintenance and Preservation; Materials; Pavements
  Session: 654
  Paper Number: 13-2250
• Influence of BituTech RAP Bioasphalt on Viscoelastic Properties of Reclaimed Asphalt Mixtures
  Abstract: The inclusion of reclaimed asphalt pavement (RAP) into asphalt paving mixtures had become more popular over the last five plus years due to the rising cost of oil, limited amount of quality virgin materials, and limited space in landfills. However, incorporating RAP into a mixture at a high rate exposes some challenges from the design perspective, especially when it comes to the influence of the stiff RAP binder on the properties of the asphalt mixture. A virgin asphalt binder softer than the conventional binder typically used for a particular project or a recycling agent are sometimes used to soften or rejuvenate the stiff, oxidized RAP binder. This paper summarizes the laboratory evaluation of one such bio-rejuvenating agent called BituTech RAP. The impact of BituTech RAP on the viscoelastic properties of high RAP content mixtures from Manitoba, Canada were evaluated for any possible moisture damage or thermal cracking problems that may arise from the use of RAP in such wet-freeze environment. Mixtures containing 15 and 50% RAP, with and without BituTech RAP, were tested using the dynamic modulus (E*) at multiple freeze-thaw cycles and the thermal stress restrained specimen test. The modified Huet-Sayegh, 2S2P1D, model was used to generate the E* complex modulus and to assess the change in loss and storage modulus resulting from the addition of the rejuvenating agent. The Cole-Cole plots showed an increase in the loss modulus for mixtures with BituTech RAP. Furthermore, an improved resistance to moisture damage was observed with the use of BituTech RAP as demonstrated with an increase in the storage and loss modulus ratios. The addition of BituTech RAP also restored the thermal cracking properties of the asphalt mixtures such as the thermal relaxation modulus, glassy transition temperature, and fracture temperature. A preliminary cost analysis was also conducted and potential cost savings were observed using BituTech RAP promoting the use of higher percentages of RAP without affecting the overall performance of the mixture.
  Authors: Hajj, Elie Y; Souliman, Mena I.; Alavi, Mohammad Zia; Loria-Salazar, Luis
  Authors: Hajj, Elie Y; Souliman, Mena I.; Alavi, Mohammad Zia; Loria-Salazar, Luis
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 743
  Paper Number: 13-2253
• Working Time, Setting Behavior, and Maturity of Concrete Mixtures and their Relationships
  Abstract: Concrete has to be workable for a certain time of period for quality construction, from placing to finishing. The working time limit, as defined by Iowa DOT, is the elapsed time from the time when cementitious materials of a concrete mixture are mixed with water to the time when the concrete has a penetration resistance of 200 psi. In the present study, working time limits of pavement concrete mixtures made with two selected retarders, with and without fly ash replacement, were measured under three different temperatures (65, 75, and 85F), and the results are compared with those measured in 1980s. A new approach to predicting concrete penetration resistance is developed based on the concrete maturity, or time-temperature factor (TTF). The results indicate that probably due to the changes in modern concrete materials (such as cement and admixture properties), some newly measured working time limits are up to 22% higher than those measured in 1980s. Concrete penetration resistance correlates well with the concrete maturity, or TTF. This relationship enables engineers to assess penetration resistance of field concrete any time, with no special consideration for the concrete curing condition.
  Authors: Hou, Qizhe; Ouyang, Chengsheng; Wang, Kejin
  Authors: Hou, Qizhe; Ouyang, Chengsheng; Wang, Kejin
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 290
  Paper Number: 13-2290
• Analysis of Temperature Effect on Bituminous Mixture Fatigue Behavior using the EBADE Test
  Abstract: The EBADE test has been developed at the Road Research Laboratory of the UPC-BarcelonaTech to assess the fatigue behaviour of the mixtures by applying a cyclic tensile-compression test to a prismatic specimen at different strain levels (strain sweep). The objective of this paper is to analyze the effect of the temperature variation on the fatigue behaviour of bituminous mixtures by means of this test. It has been studied a dense mixture manufactured with four different bitumens: two modified bitumens, one with polymer and the other with crumb rubber; and the other two with conventional bitumens, with same penetration but different source. The results show the difference of the mixture behaviour with the polymer modified bitumen with respect to the rest of bitumens tested at the temperature range considered. Furthermore, it has been analysed the effect of temperature variation in the mixture on the pavement design and it has been shown a certain contradiction between the results obtained from the analytical calculations and the loss of ductility experienced by the mixtures at low temperatures.
  Authors: Perez-Jimenez, Felix Edmundo; Botella Nieto, Ramon; Miró, Rodrigo; Martinez, Adriana Haydee
  Authors: Perez-Jimenez, Felix Edmundo; Botella Nieto, Ramon; Miró, Rodrigo; Martinez, Adriana Haydee
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 840
  Paper Number: 13-2477
• Laboratory Test Methods for Polishing Asphalt Surfaces and Predicting Their Skid Resistance
  Abstract: In this paper, laboratory test methods reproducing phenomena affecting pavement skid resistance evolution are presented. Polishing tests are performed by Wehner/Schulze machine to simulate the polishing induced by traffic and the binder removal phase (typical for bituminous asphalt concrete). Accelerated ageing tests are performed by a weatherometer, operating conditions being adjusted according to local weather conditions, to simulate the binder ageing responsible for friction increase at early age. With respect to seasonal variations, a new test was developed to evaluate the effect of pollutants deposited on the road and the washing effect of rainfalls. Description of specimens and test procedures is given. Simulations are compared to observations to check their relevance.A model is developed to combine, in a physical way, laboratory test results and give place to a prediction of the friction-polishing duration curve. Conversions are done to predict actual skid resistance variation from laboratory polishing curve. Predictions are compared to road data and results are discussed.
  Authors: Do, Minh-Tan; Kane, Malal; Cerezo, Veronique
  Authors: Do, Minh-Tan; Kane, Malal; Cerezo, Veronique
  Year: 2013
  Document Type: Paper
  Subject: Materials; Pavements
  Session: 517
  Paper Number: 13-2444
• Improving Welded Joint Fatigue Life Using Shot Peening or Grinding
  Abstract: Steel structures are mainly prone to two types of degradation: corrosion and fatigue particularly in the case of welded structures. The presented work aims at investigating two treatment methods to increase the fatigue life expectancy of welded steel joints in civil engineering structures. It includes both numerical and experimental investigations and is interested in the use of grinding and shot peening. As far as experimental investigations are concerned, for both treatment methods and for untreated samples, the stress concentration coefficients are determined, surface residual stresses are measured using X-ray diffraction and fatigue tests are conducted. The results allow explaining for both methods the observed improvements in fatigue behaviour. As far as numerical investigations are concerned, the presented work concerns the use of a finite element model to simulate welding process. This allows the determination of residual stresses due to welding operation and their comparison with the former experimental measures. Results are satisfactory enough, and, though some improvements regarding the initial stress state and the modelling are still under progress, it should be used in a following study to model treatment operations to get a better understanding of their potentiality and the parameters that affect their efficiency.
  Authors: Chataigner, Sylvain; Dieng, Lamine; Guiot, Kevin; Grasset, Michel
  Authors: Chataigner, Sylvain; Dieng, Lamine; Guiot, Kevin; Grasset, Michel
  Year: 2013
  Document Type: Paper
  Subject: Bridges and Other Structures; Maintenance and Preservation; Materials
  Session: 401
  Paper Number: 13-2448
• Evaluation of Environmental Susceptibility of Bituminous Mastic Viscosity as a Function of Mineral and Biomass Fillers
  Abstract: In addition to allowing for the load transfer in the aggregate skeleton, bituminous mastics influence many of the other important asphalt mixture properties, such as the overall stability of the mixture, air void distribution, bitumen drain-down during transport, its workability during the laying process and the overall in-time performance of the pavement. To understand the properties of asphalt mixtures and its resistance against environmentally induced failure mechanisms, it is of paramount important to not only study bitumen and the asphalt mixture, but also the mastic itself. Current asphalt design procedures do not take the mastic behavior into account which is an important flaw in our current ability to design and predict asphalt concrete response. In this paper, results of an ongoing research project are given which focuses on enhancing the understanding of the mastic phase as well as develop a new test protocol to characterize mastics. A description is given of the measurements of mastic viscosity for different types of mastics in which the bitumen source is kept as a constant, but with varying fillers as well as concentrations. The environmentally susceptibility was hereby also investigated by conditioning the samples to ageing and moisture conditioning. In addition to some of the traditional fillers, biomass fillers were also included in some of the mastics to show their impact on the viscosity under varying conditions. Results showed, the developed test protocol was able to clearly identity filler properties on the mastic viscosity. Furthermore, a critical filler concentration was identified beyond which the viscosity behaviour becomes non-linear. It is also showed that the moisture and aging have significant effect on the viscosity of mastics.
  Authors: Hesami, Ebrahim; Bidewell, Nathan; Birgisson, Bjorn; Kringos, Niki
  Authors: Hesami, Ebrahim; Bidewell, Nathan; Birgisson, Bjorn; Kringos, Niki
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 743
  Paper Number: 13-2501
• Development of a Calibration Testing Protocol for the Permanent Deformation Model of Asphalt Concrete
  Abstract: Recent permanent deformation modeling research at North Carolina State University has resulted in the so-called shift model, which is capable of expressing the permanent strain growth of asphalt concrete as a function of deviatoric stress, load time, and temperature, based on the time-temperature superposition and time-stress superposition principles. This paper presents an efficient calibration test protocol for the shift model, as well as verification of the model. The proposed test protocol is comprised of triaxial stress sweep (TSS) tests and a reference test. The TSS test is suggested to reduce the number of tests required by applying three deviatoric stresses within one test. Each TSS test is performed at three temperatures: high (TH), intermediate (TI) and low (TL). The reference test is a triaxial repeated load permanent deformation (TRLPD) test conducted at TH only. The shift model is calibrated for the polymer-modified dense-graded NY9.5B mix, and the calibrated model is applied successfully to predict strain growth for the composite tests at the three study temperatures and for random load tests at TH. The calibration testing procedure is optimized for the asphalt mixture performance tester (AMPT). The TSS tests take approximately 2.9 hours at TH and 1.5 hours at TI and TL. Thus, the proposed test protocol requires about a day to complete one set of calibration tests. Within two to three days of testing, depending on the number of replicates, the calibrated shift model is capable of predicting permanent strain growth for different temperatures, load times, and deviatoric stresses.
  Authors: Choi, Yeong-Tae; Kim, Y. Richard
  Authors: Choi, Yeong-Tae; Kim, Y. Richard
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 599
  Paper Number: 13-2555
• Linear and Nonlinear Viscoelastic Analysis of Bituminous Mortar
  Abstract: Bituminous materials exhibit either one or a combination of viscous, elastic and viscoelastic response. When applied loads are limited, their behavior can be considered linear. For higher loads they exhibit a nonlinear response. In relation to pavement performance,understanding the behavior of the binders for loads corresponding to the magnitude and frequency of the truck loading is important. With the framework of Porous Asphalt (PA)application, this paper investigates the behavior of a bituminous mortar at various temperatures and shear stress levels. A Dynamic Shear Rheometer setup (DSR) with specimen geometry specially designed for mortar testing was utilized. The mortar, which consisted of bitumen, filler and fine fractions of sand, was produced according to a standard PA mixture recipe. Various measurements conducted at the linear viscoelastic range showed the utilized setup provided very good test result repeatability. The nonlinear behavior was obtained by performing tests at high shear stress levels. The observed nonlinear behavior was described using Schapery nonlinear theory. To allow numerical use, three dimensional form of the theory was implemented in ABAQUS using user material subroutines. For code verification, time and frequency domain simulations were performed so as to reproduce the experimental data. Good comparisons between simulated and measured data were obtained. The paper thoroughly discusses the testing methods, result interpretations, description and finite element simulation works. It also discusses the implications of the results for future use in available PA design tools.
  Authors: Woldekidan, Milliyon Fekade; Huurman, Marinus; Pronk, Adriaan
  Authors: Woldekidan, Milliyon Fekade; Huurman, Marinus; Pronk, Adriaan
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 374
  Paper Number: 13-2557
• Experimental Study on Nanometer TiO2 Doped with Fe3+ for Purification Effect of Automobile Exhaust in the Tunnel
  Abstract: This paper presents an experimental approach to study purification effect of automobile exhaust. Sol-gel method was used to prepare Fe3+ modified Titanium dioxide (TiO2). Purification tests were conducted in a self-developed instrument to study catalytic effects of TiO2 doped with different contents of Fe3+ through degradation rate. The modification mechanism was studied by X-ray diffraction (XRD) scanning. Results showed that doping iron ion had improved the light catalytic performance of nanometer through inhibiting the growth of TiO2 grain size. TiO2 doped with 0.1% iron ion showed the best catalytic effect. The degradation rates of CO and CO2, HC and NOX were 6.9%, 7.9%, 2.3% and 14.9% higher than the unmodified TiO2 under ultraviolet light conditions, respectively., 0.6%, 0.6%, 2.3% and 8.2% higher than the unmodified under incandescent light conditions, respectively.
  Authors: Jianzhong, Pei
  Authors: Jianzhong, Pei
  Year: 2013
  Document Type: Paper
  Subject: Environment; Materials; Pavements
  Session: 292
  Paper Number: 13-2563
• Identifying Improved Standardized Tests for Measuring Cement Particle Size and Surface Area
  Abstract: The Blaine fineness (Blaine) of a cement powder is a single parameter that is meant to characterize the specific surface area of a cement, and is assumed to be linked to physical and mechanical properties of the hydrated cement such as strength, setting time, and rheology. A single parameter cannot characterize the particle size distribution of a cement particle size distribution, upon which the hydration kinetics and solid properties depend. And as the cement industry continues to develop more sophisticated blended cements, it will be even more clearly seen that a single parameter fails to capture the true complexity of the cement. The laser diffraction (LD) measurement of the entire particle size distribution is currently being used by cement producers for quality control of their cements while still measuring the Blaine, which is based on surface area measurement. Despite its wide use by the cement industry, LD is not a standardized test. This project’s goal is to examine various tests, such as laser diffraction and Blaine, which measure the particle size distribution and total surface area of cement powder, and then determine the most appropriate test based on correlation with macro-properties of the cement paste or mortar. In addition, the shape of the cement particles, for a partial particle size range, was determined using X-ray computed micro-tomography (X-Ray CT) and the relationship between X-ray CT, the Brunauer-Emmett-Teller surface area method (BET) (surface area), laser diffraction, and Blaine measurements was explored. The more fundamental and sophisticated experiments, nitrogen BET and X-ray CT, were used as “ground truth” to critically evaluate the laser particle size distribution and Blaine fineness measurements. The standardization of the laser diffraction test method is proposed.
  Authors: Ferraris, Chiara F.; Garboczi, Edward J.
  Authors: Ferraris, Chiara F.; Garboczi, Edward J.
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 288
  Paper Number: 13-2578
• Comparison of Uniaxial and Four-Point Bending Fatigue Tests for Asphalt Mixtures
  Abstract: The fatigue properties of asphalt mixture estimated by the different fatigue tests in the laboratory are difficult to compare with each other. One of the reasons is that for so called inhomogeneous tests which do not have a uniform stress-strain distribution, the measured stiffness is weighted overall stiffness which does not really represents the stiffness of the damage zone. For homogenous fatigue tests, the stress-strain field within the specimen is uniform in theory. In this case, the measured stiffness corresponds to a material property. It is supposed that the stiffness evolutions in the inhomogeneous tests might be described by the results from the homogenous test. In this paper, the results of uniaxial tension and compression (UT/C) fatigue test and four-point bending (4PB) fa-tigue test are described and compared. The evolutions of the stiffness and phase angle are simulated by means of the partial healing (PH) model. With the model parameters, the local stiffness for each unit volume of the beam is calculated. It is found that based on the measured overall stiffness, the classical fatigue life Nf,50 of the beam in the 4PB fatigue test is larger than that of the cylinder in the UT/C fatigue test. However, in the midsection of the beam, the local stiffness evolution is similar to that observed in the UT/C fatigue tests. Based on the local stiffness concept, the comparable fatigue lines can be obtained from the UT/C and 4PB fatigue tests.
  Authors: Li, Ning; Pronk, Adriaan; Molenaar, André; van de Ven, Martin F. C.; Wu, Shaopeng
  Authors: Li, Ning; Pronk, Adriaan; Molenaar, André; van de Ven, Martin F. C.; Wu, Shaopeng
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 653
  Paper Number: 13-2610
• Performance of Pore-Lining Impregnants in Concrete Protection by Unidirectional Salt-Ponding Test
  Abstract: Until recently, solvent based forms of monomeric alkyl (isobutyl)-trialkoxy silane, produced under various trade names, were exclusively used in the UK for concrete protection of transportation structures and other structures subject to surface salt contamination. Reflecting the move toward more sustainable construction, with increasing demand for less hazardous materials, alternative protective treatments have emerged, these based on various aqueous formulations. These include dual purpose materials for protection and concrete colouration. At the same time, developments in nano materials has resulted in the availability of a low hazards, pure silane that is neither water nor solvent based. This investigation evaluates the performance of this material together with three water based materials in respect to their resistance to water and salt solution absorption, and chloride ion penetration. A comparative investigation is included to assess the possibility of using convenient concrete cubes rather than larger scale slabs for chloride contamination testing by the salt ponding method. The results of the study are particularly relevant to older reinforced concrete structures, ones that frequently suffer low concrete cover to their steel reinforcing bars.
  Authors: Rahman, Mujib; Chamberlain, Denis; Balakhrishna, M; Kipling, Judith
  Authors: Rahman, Mujib; Chamberlain, Denis; Balakhrishna, M; Kipling, Judith
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 288
  Paper Number: 13-2677
• Mechanical Performance of Asphalt Binders Modified with Free Radical-Treated Electronic Waste Plastics
  Abstract: The primary objective of this investigation is to determine the improvement in mechanical performance for free radical treated electronic waste (e-waste) plastic modified asphalt binders, referred hereafter as treated e-waste binders, versus conventional asphalt binders. Treated e-waste modified asphalt binders are modified asphalt binders blended with various percentages of powdered electronic waste plastic or polymers. The free radical initiator, cumene hydroperoxide, induced bonding between the plastic polymer and the asphalt binder molecules. Cumene hydroperoxide was used to treat the electronic waste plastic powders to improve asphalt binder and e-waste plastic interaction. The secondary objective of this research effort is to determine if small percentages of treated e-waste plastic improved e-waste modified asphalt binder performance at all temperature ranges. The percentage of e-waste blended with asphalt binders was 5%. Rotational viscosity, dynamic shear rheometer, and bending beam rheometer testing were conducted. This investigation showed that low percentages of treated e-waste modified asphalt binders improved high temperature performance in terms of rutting susceptibility, workability of asphalt binders, and showed viscoelastic behavior similar to the control binder. At best, low percentages of treated e-waste binders met but didn’t exceed the control asphalt binder performance.
  Authors: Colbert, Baron; You, Zhanping; Heiden, Patricia A.
  Authors: Colbert, Baron; You, Zhanping; Heiden, Patricia A.
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 596
  Paper Number: 13-2692
• Development, Implementation, and Verification of Performance Based Specifications for High-Performance Thin-Lift Overlay Mixtures
  Abstract: State DOT agencies from the Northeast Pavement Preservation Partnership (NEPPP) as well as the Pennsylvania Asphalt Pavement Association (PAPA) were involved in the development of a pilot specification for high performance thin overlay (HiPO) mixtures. The pilot specification addressed surface preparation, material properties (binder, aggregate, tack coat), mixture design requirements, Reclaimed Asphalt Pavement (RAP) testing requirements, performance criteria for the asphalt binder in terms of thermal cracking, and mixture performance criteria in terms of reflective cracking, thermal cracking, fatigue cracking, and rutting. The National Center for Pavement Preservation (NCPP) published and posted the pilot specification on the AASHTO Transportation System Preservation Technical Services Program (AASHTO TSP2) web site. From the posting of the pilot specification, multiple state agencies expressed interest in utilizing the pilot specification for demonstration paving projects.In 2011, three state agencies (Minnesota, New Hampshire, and Vermont) placed demonstration projects of the HiPO mixture incorporating up to 25% RAP. The focus of this study was to assist the three state DOT agencies in evaluating the performance of the plant produced mixtures from the field projects in the laboratory based on performance criterion listed in the pilot specification. Based on the evaluation of the mixtures and field observations, several recommendations are provided to refine the pilot specification. In particular, it is recommended to put more emphasis on the testing of the RAP materials as it has showed a significant impact on the performance of the mixtures. Additionally, several criteria will be monitored in order to correlate with field performance.
  Authors: Mogawer, Walaa S.; Austerman, Alexander J.; Kluttz, Robert Q.; Mohammad, Louay N.
  Authors: Mogawer, Walaa S.; Austerman, Alexander J.; Kluttz, Robert Q.; Mohammad, Louay N.
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 655
  Paper Number: 13-2728
• Structural Characterization of Micromechanical Properties in Asphalt Using Atomic Force Microscopy
  Abstract: This paper presents the findings from a study that semi-quantitatively evaluates the micro-rheological properties of the asphalt binder using Atomic Force Microscopy (AFM). The paper also presents the differences between these properties amongst the various microstructures within an asphalt binder as well as the influence of oxidative aging on these properties. The following sections describe background information and the research approach used to achieve the aforementioned objectives. The approach described uses nano-indentation experiments performed within a micro-grid of asphalt phases to determine micromechanical properties such as stiffness, adhesion and elastic/plastic behavior. The materials evaluated include asphalts AAB and AAD from the Materials Reference Library (MRL) of the Strategic Highway Research Program (SHRP), chosen due to variations in crude source, chemical composition and elemental analysis for each asphalt type. The analysis of nano-indentation creep measurements corresponding to phase-separated regions revealed heterogeneous domains in asphalt with different mechanical properties, and oxidative aging was found to induce substantial microstructural change within these domains, including variations in phase structure, phase properties and phase distribution. The form and extent of these changes, however, were different for each asphalt studied. The interpretation of data collected from the AFM experiments in this study advances the understanding of the microstructural makeup of asphalt binders and the response of the microstructural phases of the asphalt binder under load as well as how the mechanical responses in the phases change with aging.
  Authors: Allen, R. Grover; Little, Dallas N.; Bhasin, Amit
  Authors: Allen, R. Grover; Little, Dallas N.; Bhasin, Amit
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 604
  Paper Number: 13-2734
• Low-Temperature Oxidation Kinetics of Asphalt Binders
  Abstract: A simple dual mechanism model successfully fits the oxidation of 12 unmodified asphalt binders3 originating from a wide variety of sources. The kinetic formulation includes fast and slow reaction paths4 in parallel with free radical interactions between the two reaction pathways as first proposed by Petersen.5 The same Arrhenius parameters are used for all 12 binders studied. Using only one adjustable parameter,6 the amount of reactive material available for the fast reaction, the differences in asphalt binder oxidation7 rates can be explained. This result suggests that unmodified asphalt binders oxidize with essentially the8 same chemical mechanisms. Since the Arrhenius parameters apply universally, a simple test may be9 performed to characterize the oxidation kinetics for unmodified binders without doing expensive long10 term oxidation experiments at multiple temperatures. A rheological study of the materials generated in the11 aging of the 12 binders using dynamic shear rheometry was also performed to investigate the relationship12 of rheological changes with chemical changes as binders oxidize. The rheometry consisted of the13 generation of a series of isothermal frequency sweeps, followed by fitting the resulting master curve with14 the Christensen-Anderson model. Simple shifting cannot account for the master curve changes, but15 changes in the Christensen-Anderson model parameters follow a log-linear relationship with regard to16 oxidation chemical changes. These fits appear to be source dependent, suggesting a two aging time17 method would be required to characterize the rheological property changes in an unmodified asphalt18 binder as it ages. Such a method would produce a complete master curve/shift function set at any extent19 of aging, suitable for input into rational performance models.20
  Authors: Glaser, Ronald R; Schabron, John F; Turner, Thomas F; Planche, Jean-Pascal; Salmans, Stephen L.; Loveridge, Jenny L
  Authors: Glaser, Ronald R; Schabron, John F; Turner, Thomas F; Planche, Jean-Pascal; Salmans, Stephen L.; Loveridge, Jenny L
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 596
  Paper Number: 13-2761
• Forensic Investigation of Uncontrolled Concrete Bridge Parapet Cracking
  Abstract: The Ohio Department of Transportation has recently identified the problem of wide-spread premature cracking of concrete bridge parapets throughout its District 12 region (Northeast Ohio). Many of the bridge decks that contain these prematurely cracked parapets are of relatively recent construction. In severe cases, replacement of the parapet may be required before replacement of the bridge deck itself. This incurs a sunk cost upon the bridge owner, as the parapets will again be replaced during the regularly scheduled replacement of the bridge deck. In a recent instance, the replacement of a cracked parapet (without replacing the deck) cost District 12 approximately $140,000. In addition, parapet walls are a crucial safety feature of roadway bridge construction, and severe deterioration of these barriers could introduce a significant safety hazard. Premature cracking of concrete bridge parapets is a potentially complex problem, with a plethora of possible causes. The objective of this study was to determine the reasons for uncontrolled concrete bridge parapet cracking, and to provide recommendations to ODOT to prevent such cracking in the future. Potential factors examined in this study included: properties of the concrete mixtures used, construction methods, joint details, composite structural action, and durability of the concrete and reinforcement, among others. Identifying the cause of, and avoiding this problem in the future, has several benefits, including: a potential cost savings for the district, increasing the safety of these structures in future construction, and increasing the overall understanding of the durability of these structures.
  Authors: Bazzo, Jeffrey; Delatte, Norbert Joseph; Kalabon, Amy
  Authors: Bazzo, Jeffrey; Delatte, Norbert Joseph; Kalabon, Amy
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 290
  Paper Number: 13-2834
• Modified Paris’ Law to Predict Entire Crack Growth in Asphalt Mixtures
  Abstract: The Paris’ law is a well-known and widely used method for predicting crack growth in engineering materials. Currently most Paris’ law model forms are formulated based on the growth of a single crack, which is not in accord with the actual way in which asphalt mixtures are damaged: a multitude of cracks propagate with increasing load applications. The parameters in these Paris’ law model forms are determined either by extensive testing and curve fitting, or by collecting data from a series of different tests. In order to predict the entire crack growth in an asphalt mixture, a modified Paris’ law is proposed in this paper, which is defined using the damage density. In addition, the procedure for determining the modified Paris’ law parameters (A' and n') is simplified so that they are easily obtained from one test on one asphalt mixture specimen. The proposed modified Paris’ law is applied to twenty different types of asphalt mixtures. The result shows that A' and n' are highly correlated with each other for the materials tested. Based on this relationship, the damage density formulated in the modified Paris’ law is proven to be monotonically related to n' through a sensitivity analysis. This suggests that n' can be used directly to compare the damage density of different asphalt mixtures. Investigation on the effects of asphalt binder, air void content, and aging period on fatigue cracking in asphalt mixtures further confirms that n' is a good indicator of the tendency of the material to crack. It can be used solely in material comparison and selection in terms of fatigue cracking, and a smaller value of n' is preferred.
  Authors: Luo, Xue; Luo, Rong; Lytton, Robert Leonard
  Authors: Luo, Xue; Luo, Rong; Lytton, Robert Leonard
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 653
  Paper Number: 13-2800
• Micromechanical Analysis of Localized Stress and Strain in Thermally Loaded Restrained Asphalt Mixtures
  Abstract: Understanding the evolution of critical stresses in as asphalt mixture during thermal cooling is very important for determination of thermal cracking resistance of pavements. An experimentally calibrated multi-phase micromechanical model of asphalt mixture undergoing thermal loading and glass transition was developed in a finite element platform using actual 2D images and binder properties. Good agreement was achieved between thermal stress predictions from the micromechanical simulation and the experimentally measured thermal stress curves. Significant stress concentration was observed in the modeled asphalt mixtures in the vicinity of the aggregate interfaces due to the irregular angular aggregate geometry, t and due to the known significant difference in stiffness between the asphalt and aggregate phase, causing a stiffening effect in the binder elements in the immediate vicinity of the fully bonded binder-aggregate interface. Analysis also showed that significant localized strains occur in the binder phase of a fully restrained asphalt sample due to the gradual reorientation of aggregates under the non-uniform stress distribution on their boundary. To apply the knowledge gained from the simulations, results were used to determine average binder strain rates in pavements undergoing typical cooling rates, for possible usage in low temperature binder characterization procedures, such as the Single Edge Notch Beam (SENB).
  Authors: Tabatabaee, Hassan A.; Bahia, Hussain U.
  Authors: Tabatabaee, Hassan A.; Bahia, Hussain U.
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 653
  Paper Number: 13-2802
• Using Viscosity at Variable Shear Rates to Evaluate Asphalt Emulsion Sprayability and Drainout Characteristics in Chip Seals
  Abstract: Streaking and drain-out are two common early chip seal failures related to the viscosity of the asphalt emulsion used. An emulsion with a high viscosity at spraying could result in streaking, while another with a low viscosity after spraying could drain off the road surface under gravity. Some emulsions also tend to show reduction in viscosity during handling, thus aggravating the potential for drain-out. The Saybolt-Furol Viscometer (SFV) (ASTM D7496) is currently used to characterize the viscosity of asphalt emulsions. However, the SFV cannot be operated under varying shear rate conditions as experienced by emulsions at different stages. In this paper, a new test procedure for evaluating sprayability, drain-out, and recovery kinetics of emulsions by the use of a rotational viscometer is presented. The test procedure allows for emulsions to be tested at a higher shear rate when evaluating sprayability and low shear rate when evaluating drain-out. Twelve emulsions of different grades and chemistries were tested. The results showed that the proposed test procedure is sensitive to emulsion chemistry, grade and testing temperature. Sprayability, drain-out and recovery kinetics were found to be significantly affected by emulsion chemistry and testing temperature. It is recommended that this variable shear-rate viscosity protocol be used as a basis for replacing the SFV test as a better performance related test method. Specification criteria can be easily developed and implemented since rotational viscometers are widely available in the industry, and there is a wealth of experience with various emulsions in the field.
  Authors: Johannes, Petrina Tutumina; Bahia, Hussain U.
  Authors: Johannes, Petrina Tutumina; Bahia, Hussain U.
  Year: 2013
  Document Type: Paper
  Subject: Maintenance and Preservation; Materials; Pavements
  Session: 654
  Paper Number: 13-2805
• Effect of Emulsion Content and Cement Loading on Cold Recycling Mixture Fracture Energy Measured Using Semicircular Bending Fracture Test
  Abstract: Cold recycling is an attractive alternative to rehabilitate asphalt concrete pavement from a cost effectiveness and sustainability standpoint. Cracking resistance is a critical property that is often not considered in the design or acceptance of cold recycling mixtures. The use of the Semi Circular Bending (SCB) fracture test with the testing parameters defined in this study provides a practical way to evaluate the cracking behavior of cold recycling mixtures. Guidance is needed to help mixture designers select proper additive types and loadings. An experimental design evaluates the effect of emulsion content and cement loading on SCB fracture energy. Results from this study are used to set minimum fracture energy thresholds when designing cold recycling mixtures.
  Authors: Charmot, Stephane; Braham, Andrew; Zheng, Kefei
  Authors: Charmot, Stephane; Braham, Andrew; Zheng, Kefei
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 653
  Paper Number: 13-2925
• Characterization of Hot-Mix Asphalt Permanent Deformation: Flow Number Test and Fn Index Concept
  Abstract: Permanent deformation (PD), or rutting, is one of the common distresses occurring in hot-mix asphalt (HMA) pavements. As part of the HMA mix- and structural-design processes to optimize field performance, various laboratory tests, including the Hamburg wheel tracking test (HWTT) and flow number (FN), have been developed to characterize the HMA mix rutting resistance. With this background, this study was conducted to explore the potential of routinely using the FN test to characterize the PD response of different types of Texas HMA mixes as a supplement to the HWTT. Towards this goal, a new PD parameter¡ªthe FN Index¡ªwas developed to differentiate and screen the HMA mixes. The research methodology incorporated a two-phase approach, namely: (1) laboratory testing and (2) field performance monitoring of selected HMA mixes under conventional traffic loading on in-service highways. Overall, the findings indicated that the FN Index, computed from the FN test data, has ability to statistically differentiate the HMA mixes evaluated as well as promising potential to supplement the HWTT for routine HMA mix-design and screening. In addition, the FN test method has a practically reasonable test time (about 3 hours per specimen) and is cost-effective. However, the inability to readily test field cores and the need for field validation with long-term performance data remain some of the key challenges to be addressed with the FN test.
  Authors: Walubita, Lubinda F.; Zhang, Jun; Haggerty, Brett; Leidy, Joe; Alvarez, Allex E.; Hu, Xiaodi; Scullion, Tom
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 599
  Paper Number: 13-1541
• Reacted and Activated Rubber: Elastomeric Asphalt Extender
  Abstract: Asphalt rubber mixtures have traditionally been difficult to produce requiring specialized plant and equipment resulting in higher costs of manufacture. This in part is due to the need to produce asphalt rubber binder by blending at high temperatures for a significant time period (around 190C for typically 45 minutes to 1 hour). The complexities in the process have resulted in asphalt rubber mixes being significantly more expensive to produce than conventional paving mixtures. A new technology which produces a “Reacted and Activated Rubber” (RAR), which is an elastomeric asphalt extender, has been developed by hot blending and activation of a rubber granulate with a selected asphalt binder and activated mineral binder stabilizer (AMBS). RAR achieves similar results comparable to other types of polymer modified binders (PMB). However, a principle advantage with RAR is that it can be easily added to any HMA manufacturing facility using systems designed to feed particulate material into a batch plant (pug-mill) or drum mix plant. This paper describes how RAR is produced from raw constituent materials. Various tests on binder contrast the performance to typical paving grades and PMBs that are used in the USA. The implementation of RAR in various types of asphalt mixtures will be discussed and demonstrative examples of test results are provided. Tests on mixtures in wheel tracking and fatigue demonstrate how the binder performance tests translate into mixture performance. In all cases evaluated, the RAR mixtures out-perform non-modified and even conventional rubber modified equivalent materials.
  Authors: Sousa, Jorge B.; Rowe, Geoffrey M.; Vorobiev, Andrey; Ishai, Ilan
  Authors: Sousa, Jorge B.; Rowe, Geoffrey M.; Vorobiev, Andrey; Ishai, Ilan
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 656
  Paper Number: 13-2941
• Nanoindentation Test Integrated with Numerical Simulation to Characterize Mechanical Properties of Rock Materials
  Abstract: It is important to determine the mechanical properties of rock materials accurately from the viewpoint of the design, analysis, and modeling of various transportation infrastructure systems. Conventional methods have some drawbacks including relatively inaccurate measurements, cumbersome testing-analysis processes, and high variability in measurements. A nanoindentation test integrated with a numerical modeling technique has been validated in other fields as an efficient and accurate tool for the characterization of the key mechanical properties of various irregularly shaped materials such as the rock materials in this study. This paper presents an integrated experimental-numerical effort based on the nanoindentation measurement and finite element modeling of a representative rock material, limestone. The experimental efforts including specimen fabrication and laboratory tests are presented, and the corresponding analyses of test results combined with the finite element technique and linear interpolation to validate the elastic property measurements are discussed. The elastic properties estimated from the nanoindentation test are similar to the simulation results, demonstrating the validity of the test method and modeling approach. The success of the proposed approach should facilitate the better design of mixtures and structures based on the more accurate characterization of the core material properties.
  Authors: Ban, Hoki; Kim, Yong-Rak; Karki, Pravat
  Authors: Ban, Hoki; Kim, Yong-Rak; Karki, Pravat
  Year: 2013
  Document Type: Paper
  Subject: Geotechnology; Materials
  Session: 291
  Paper Number: 13-2294
• Effects of Curing and Oxidative Aging on Raveling in Emulsion Chip Seals
  Abstract: Although chip seals have a proven history of performance, several distresses are commonly encountered in the field. The most common distresses in chip seals are flushing or bleeding and aggregate loss from the top layer (i.e., raveling). Raveling is not restricted to the early life of the chip seal, and may continue to occur throughout the service life. The current state of knowledge and testing with regard to the mechanisms governing raveling in chip seals does not sufficiently account for the effects of in-service emulsion-aggregate bond maturation and oxidative aging on chip loss over the expected service life of the chip seal. It is hypothesized that emulsion-aggregate adhesion controls the early raveling process, while the residual asphalt binder rheological properties and aggregate embedment in the emulsion all contribute to later reveling in chip seals. Raveling of chip seals subjected to varying degrees of time-temperature conditioning was evaluated to account for different chemical and physical interactions at the aggregate-asphalt interface. Testing results showed that the rate of in service raveling is dependent on the curing process and subsequent in-service oxidative aging as the adhesive and cohesive forces at the emulsion-aggregate interface change. The initial bond maturation results in a decreased rate of chip loss, while the in-service oxidative aging of the asphalt emulsion leads to a higher aggregate loss as a result of the emulsion’s strain intolerance and inability to relax stresses induced by traffic.
  Authors: Moraes, Raquel; Bahia, Hussain U.
  Authors: Moraes, Raquel; Bahia, Hussain U.
  Year: 2013
  Document Type: Paper
  Subject: Maintenance and Preservation; Materials; Pavements
  Session: 654
  Paper Number: 13-2758
• Evaluation of Tensile Property of Warm-Mix Asphalt Concretes at Low Temperatures
  Abstract: The tensile strength (St) of WMA and HMA concretes were measured by indirect tensile strength test methods at 25, 5, -5, -15, -25 and- 35¡É. Fracture energy (FE) was calculated from each of the tensile strength test curves. Two WMA additives and two polymer modifiers were used to produce WMA mixtures at 135¡É in the laboratory. All asphalt concretes evaluated in this study showed St increase by temperature decreases, peaking at -15¡É or -25¡É, then decreasing with further lowering of temperatures. The St values of WMA mixtures were observed to be higher than those of HMA mixtures, and, in most cases, at all low temperatures evaluated in this study. After being subjected to differential thermal contraction damage at -15 and/or -20¡É, most of the WMA mixtures showed higher St than HMA mixes at severely low temperatures (-25 and -35¡É). Therefore, it was concluded that the WMA mixtures had stronger tensile strength than HMA mixtures at low temperatures when prepared with the same low-temperature PG binders, even though they were produced at a relatively lower aggregate-heating temperature.
  Authors: Kim, Sungun; Choi, Hyun Jun; Kim, Kwang W.
  Authors: Kim, Sungun; Choi, Hyun Jun; Kim, Kwang W.
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 597
  Paper Number: 13-2747
• Modeling and Experimental Measurements of Asphalt Mixture Fracture Properties Using Semicircular Bending Test
  Abstract: The semi-circular bending (SCB) test is becoming a more popular candidate for measuring asphalt mixtures fracture properties. It is a simple and inexpensive test, the sample preparation is straight forward, and the mode of failure in SCB samples is due to tensile stress induced by bending. The objective of this study was to investigate the feasibility of using the SCB test to quantify asphalt mixture fracture properties. Seven asphalt mixtures were tested in the laboratory. Part of the experimental program results were used to develop and calibrate an extended finite element model (XFEM) coupled with cohesive zone modeling (CZM). The XFEM-CZM model was then used to investigate crack propagation in SCB and to predict SCB simulations for experimental results not used in the calibration process. The model calibration had a very good agreement with the experimental results and the model successfully predicted the SCB testing results. Based on XFEM-CZM results the crack propagation in SCB is mainly attributed to tensile stresses.
  Authors: Mahmoud, Enad; Saadeh, Shadi; Hakimelahi, Hamed; Harvey, John
  Authors: Mahmoud, Enad; Saadeh, Shadi; Hakimelahi, Hamed; Harvey, John
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 653
  Paper Number: 13-2635
• New Developments in Selecting Chemical Treatments for Gravel Roads
  Abstract: There is an increasing need and interest in the use of chemical treatments to reduce maintenance and gravel replacement on gravel roads. However, choice of the most appropriate additive is difficult because of the proprietary nature of many of the additives available. This paper offers an updated selection guide, which is based on the practitioner understanding the roads that require treatment in terms of traffic, climate, geometry, and materials; understanding additive types and categories; and understanding the need to request potential vendors to categorize their additives accordingly. Based on the information collected, appropriate additive categories and if applicable, sub-categories, can be selected from two charts. The selection can be refined by evaluating expected performance using prediction charts that are based on material properties determined from simple, inexpensive laboratory tests.
  Authors: Jones, David
  Authors: Jones, David
  Year: 2013
  Document Type: Paper
  Subject: Geotechnology; Materials; Pavements
  Session: 740
  Paper Number: 13-2957
• Recovery and Laboratory Testing of Asphalt Emulsion Residue: Application of Simple Aging Test and 4-mm Dynamic Shear Rheometry
  Abstract: ABSTRACTThis study involves application of two new test methods to the recovery of asphalt emulsion residue, long-term oxidative aging of the residue, and mechanical testing of the unaged and aged residue to determine low and intermediate temperature rheological properties. The two new methods are: (1) the simple aging test (SAT) which is a thin-film (300 µm) oxidative aging test, and (2) a dynamic shear rheometry (DSR) technique (commonly referred to as 4mm DSR) that allows testing to -40°C, requires only ~ 25 mg, and includes a correction for instrument compliance. Three polymer modified emulsions are recovered by two methods: (1) ASTM D7497 - Method B, and (2) using a SAT plate. Both methods use the same evaporative technique to recover the residue (6 hours at 60°C in a forced draft oven). The rheological properties (m-value, G* sin ä, and ductility) of the recovered emulsion residues by both methods are reported as well as the rheological properties of the aged emulsion using the SAT. The rheological properties of the unaged emulsion residues recovered by both methods are roughly equivalent.
  Authors: Farrar, Michael J.; Salmans, Stephen L.; Planche, Jean-Pascal
  Authors: Farrar, Michael J.; Salmans, Stephen L.; Planche, Jean-Pascal
  Year: 2013
  Document Type: Paper
  Subject: Maintenance and Preservation; Materials; Pavements
  Session: 654
  Paper Number: 13-2982
• Three-Dimensional Fracture Modeling of Epoxy Asphalt Concrete Using Heterogeneous Discrete Element Model
  Abstract: Cracking in epoxy asphalt mixture (EAM) used for steel bridge wearing course continues to be a major cause of structural and functional deterioration of this material, particularly in cold climate. Therefore, it is important to understand the complex fracture behavior of this heterogeneous mixture, which is composed of irregularly shaped and randomly distributed aggregates and mastics. A three-dimensional (3-D) fracture model independent of laboratory, based on the discrete element method (DEM), is created using a randomly-truncating algorithm to investigate the fracture behavior. A bilinear displacement-softening model is implemented into the DEM framework to simulate the crack initiation and propagation in EAM. Several experimental tests are performed to obtain input parameters of materials for numerical models. The simulation results of a single-edge notched beam test, are shown to compare favorably with experimental results and accurately capture the distributions of fracture zone and stress within the model. The modeling technique herein provides more details of the progressive cracking process in laboratory fracture test, and 3-D visualization of crack trajectories also demonstrate the influence of heterogeneity on crack path. The 3-D user-defined microstructural DEM fracture model has the potential ability to help understand various fracture mechanisms and shows a realistic cracking process of quasi-brittle materials such as EAM.
  Authors: Wang, Jiangyang; Qian, Zhendong; Wang, Linbing
  Authors: Wang, Jiangyang; Qian, Zhendong; Wang, Linbing
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 653
  Paper Number: 13-2994
• Investigation of Possible Improvements of Interface Strength in Asphalt Pavements
  Abstract: Several treatments of the interface between binder and wearing courses are presented and their results may be used for outlining possible ways to improve the interlayer bond strength. The investigated operations are performed on hot binder course, by roughening the binder surface so to ensure a better locking (tracks of a toothed compactor roller, chip coat with different sizes and materials), and on cold binder course, by simulating the operation of overlay with the traditional techniques (hot bitumen and tack coats for two residual application rates) along with furrowed, dirty or smooth binder course surface. The shear strength features are evaluated through the Sapienza Inclined Shear Test Machine.According to the achievements, all the interface treatments show an improvement in the shear behavior in comparison with the case with no treatment. The operations performed on binder course to modify its surface record a considerable improvement of the shear strength. In contrast to the expectations, the higher results are achieved by those treatments intended to reproduce pejorative condition of the interface.
  Authors: D'Andrea, Antonio; Tozzo, Cristina
  Authors: D'Andrea, Antonio; Tozzo, Cristina
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 655
  Paper Number: 13-3020
• Automated Measurement and Control of Slump and Water Content for Concrete Quality Assurance
  Abstract: This paper presents an analysis of data on 8,226 loads of ready mixed concrete as measured by truck-mounted, automated slump management equipment. This equipment measures and controls slump and water content from batching to final discharge, and also records concrete temperature, admixture use, drum rotation speed and number of revolutions, and time. The data indicate that the use of this equipment resulted in concrete arriving at the jobsite at the correct slump for discharge, reduced variability in slump at discharge, and more consistent mixing after loading. Data also showed that water additions can be made, uniformly mixed, and fully documented while the truck is in transit. The paper describes how the documentation and control provided by such equipment can be part of a quality assurance program.
  Authors: Koehler, Eric
  Authors: Koehler, Eric
  Year: 2013
  Document Type: Paper
  Subject: Construction; Materials; Pavements
  Session: 427
  Paper Number: 13-3031
• X-Ray CT-Based Three-Dimensional Microstructural Modeling of Asphalt Concrete
  Abstract: This paper presents a three-dimensional (3D) microstructural computational modeling framework based on X-ray CT images to predict the thermo-mechanical response of asphalt concrete. 3D microstructures for dense-graded asphalt concrete (DSG) and stone matrix asphalt (SMA) are generated and contain two phases: aggregate and matrix. The aggregate phase is considered as an elastic material and the matrix phase is modeled as a thermo-viscoelastic, thermo-viscoplastic, and thermo-damage material. The reconstructed 3D microstructures are used in simulating uniaxial and repeated creep recovery tests to obtain stress-strain response and damage propagation, and to investigate the effect of strain rate, temperature, and loading type. Consequently, the behavior of two types of asphalt concrete (DSG and SMA) are investigated and compared. The presented results show that the proposed framework is capable to effectively predict the overall thermal mechanical response of asphalt concrete and can be useful to compare the behavior of different types of asphalt concrete. Therefore, the X-ray based microstructural modeling framework can be used to understand how the constituents in microscopic level of asphalt concrete affect the behavior in macroscopic level of asphalt concrete. Moreover, guidelines for design of asphalt concrete to have better performance can be provided by such proposed framework.
  Authors: You, Taesun; Abu Al-Rub, Rashid K.; Masad, Eyad A.; Little, Dallas N.
  Authors: You, Taesun; Abu Al-Rub, Rashid K.; Masad, Eyad A.; Little, Dallas N.
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 599
  Paper Number: 13-3013
• Evolution of Crossover Modulus with Oxidative Aging: Method to Estimate Change in Viscoelastic Properties of Asphalt Binder with Time and Depth on the Road
  Abstract: This study is based on recovered binders from a hot mix asphalt comparative test site constructed in Arizona in 2001 on mix collected during construction and cores collected in 2005 and 2010. The intent of the study is to evaluate the potential of using the evolution of the binder crossover modulus with time and depth in the pavement to determine the change in linear viscoelastic properties of the binder during the life of the pavement. The crossover modulus is one of three parameters in the Christensen-Anderson (CA) complex shear modulus model. The CA model is used in this study to develop complex modulus and phase angle master curves of the binder as a function of field time, depth and temperature. Based on the master curves generated the change in SHRP specification parameters such as m-value and creep stiffness as well as mix dynamic modulus with time and depth on the road are demonstrated. In addition, although asphalt dependent, a linear relationship between oxygen uptake and the log of the crossover modulus is reported.
  Authors: Farrar, Michael J.; Turner, Thomas F; Planche, Jean-Pascal; Schabron, John F; Harnsberger, P. Michael
  Authors: Farrar, Michael J.; Turner, Thomas F; Planche, Jean-Pascal; Schabron, John F; Harnsberger, P. Michael
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 374
  Paper Number: 13-3059
• Modeling Water Vapor Diffusion in Pavement and Its Influence on Fatigue Crack Growth of Fine Aggregate Mixture
  Abstract: This paper describes two key objectives: the first objective is to develop a method of predicting and quantifying the amount of water that can enter into a pavement system by vapor transport; the second objective is to identify to which extent the fatigue crack growth of pavement would result from such moisture accumulation. To fulfill these two objectives, a diffusion model was first established to illustrate the wetting process of the surface asphalt layer due to the vapor migration from subgrade soil into the upper layer. Secondly, in order to quantify the degree of moisture damage induced by water vapor diffusion, fine aggregate mixture (FAM) specimens were fabricated and conditioned at different levels of relative humidity (RH) in closed vacuum desiccators that allows little temperature fluctuation. Moreover, the moisture conditioned specimens were tested using a newly developed repeated direct tension (RDT) test method to evaluate the fatigue crack growth. The RDT test greatly reduced the stress state complexity within the specimens by evenly distributing stress over the cross section area of the cylindrical specimen. Compared to the previous torsional test, the newly proposed test protocol was more efficient in characterizing the moisture susceptibility of the asphalt mixture. A major finding in this paper is that the higher level of RH in as asphalt surface layer will induce significantly higher crack growth rates.
  Authors: tong, yunwei; Luo, Rong; Lytton, Robert Leonard
  Authors: tong, yunwei; Luo, Rong; Lytton, Robert Leonard
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 599
  Paper Number: 13-3102
• Data Fusion for Multiple-Sensor Nondestructive Evaluation on Concrete Bridge Deck
  Abstract: Corrosion of buried reinforcing steel in concrete bridge decks is one of the dominant damage types in terms of overall bridge maintenance costs. Early-stage detection, location and assessment of corrosion can significantly reduce the damage progression and maintenance costs. This study aims to assess and improve the ability of various nondestructive evaluation (NDE) methods to detect the early stages of corrosion. This paper presents the techniques to apply data fusion on two NDE methods – ground penetrating radar and half-cell potential. Fusing data from multiple NDE methods may result in better and more accurate evaluation of active corrosion.
  Authors: Cui, Jianhong; Huston, Dryver Roy; Arndt, Ralf
  Authors: Cui, Jianhong; Huston, Dryver Roy; Arndt, Ralf
  Year: 2013
  Document Type: Paper
  Subject: Bridges and Other Structures; Maintenance and Preservation; Materials
  Session: 401
  Paper Number: 13-3115
• Influence of Cecabase on Mechanistic, Economical, and Environmental Attributes of Polymer-Modified Asphalt Mixture
  Abstract: In the last decades, extensive amount of experimental laboratory and field studies were conducted with different warm mix asphalt (WMA) technologies around the world. While good performance for the WMA mixtures has been reported, their use with polymer-modified asphalt binders is still creating a concern for some highway agencies. This paper summarizes the laboratory evaluation of one of those WMA products called Cecabase™ RT with a typical dense-graded polymer-modified asphalt mixture used in California and Nevada. The objective of this paper was to assess whether Cecabase™ RT negatively influence the outstanding performance and durability experienced by the state DOTs for the polymer-modified asphalt mixture. The WMA mixture was produced in the laboratory and compared to an HMA control mixture using identical aggregates, binder and mix design. Overall, the presented results indicated that the use of the Cecabase™ RT warm-mix additive at lower production and compaction temperatures resulted in a similar or better resistance to moisture damage, rutting, and fatigue cracking when compared to the conventional HMA. Preliminary calculations showed potential fuel savings associated with the use of Cecabase™ RT. In addition, measurable energy savings and significant reduction in CO2 emissions are anticipated with the use of Cecabase™ RT additive compared to the conventional HMA.
  Authors: Hajj, Elie Y; Souliman, Mena I.; Cortez, Edward; Jorda, Eric
  Authors: Hajj, Elie Y; Souliman, Mena I.; Cortez, Edward; Jorda, Eric
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 743
  Paper Number: 13-3133
• Comparative Experimental Performance of Bridge Deck Slabs with AFRP and Steel Prestressed Precast Panels
  Abstract: Full-depth precast concrete panels expedite the construction process, enhance safety and quality control, and reduce the on-site labor requirements for bridge deck slab application. However, corrosion-induced deterioration of conventional steel during the lifetime of the structure is a serious concern affecting the durability and serviceability of the deck panels. Although replacing conventional steel with fiber reinforced polymer (FRP) bars has become more prevalent over the past few decades to overcome corrosion issues, there is still need for a comprehensive experimental study to investigate the structural performance of FRP concrete bridge deck slab with precast prestressed panels at full-scale and to address constructability issues as well. In this paper, a full-scale bridge deck slab consisting of full-depth precast panels reinforced and prestressed with aramid fiber reinforced polymer (AFRP) bars is experimentally investigated in terms of constructability and overall structural performance. Then it is compared to a similar system but reinforced with conventional steel and prestressing strand, deemed as the control specimen. The experimental results show the applicability of the proposed system having sufficient strength per AASHTO LRFD Bridge Design Specifications (2010) and considerable deformability when compared to the conventional system.
  Authors: Pirayeh Gar, Shobeir; Head, Monique Hite; Hurlebaus, Stefan; Mander, John
  Authors: Pirayeh Gar, Shobeir; Head, Monique Hite; Hurlebaus, Stefan; Mander, John
  Year: 2013
  Document Type: Paper
  Subject: Bridges and Other Structures; Design; Materials
  Session: 461
  Paper Number: 13-3207
• Performance Evaluation of Asphalt Mixtures Blended by Nonmodified Nanoclay and Polymer-Modified Nanoclay
  Abstract: The two nanomaterials (non-modified nanoclay and polymer modified nanoclay) were used as modifiers to improve the mechanical and pavement properties of the asphalt mixture. The 2% and 4% non-modified nanoclay (NMN) and polymer modified nanoclay (PMN) were added into the control asphalt binder using the high shear mixer. The prepared asphalt binders were blended with aggregates and the asphalt mixtures were compacted following SuperpaveTM specifications. After the preparation of asphalt mixtures, the performance tests including the dynamic modulus test, rut susceptibility test with asphalt pavement analyzer, flow number test, and indirect tensile test were conducted to evaluate the properties of the control and nano-modified asphalt mixtures and to assess the positive effect of NMN and PMN in the asphalt mixture. The testing results show that the dynamic modulus, flow number, resilient modulus, and dry and wet tensile strength of NMN and PMN modified asphalt mixtures are all improved. One of the direct benefits of using the nanomaterials is that the rut depths of NMN and PMN modified asphalt mixtures are decreased relative to the control asphalt mixture.
  Authors: Yao, Hui; You, Zhanping; Wang, Hainian; Shi, Xianming; Li, Liang
  Authors: Yao, Hui; You, Zhanping; Wang, Hainian; Shi, Xianming; Li, Liang
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 596
  Paper Number: 13-3263
• Fatigue Simulation of Cement Concrete Bridge Pavement Using Dissipated Energy Approach
  Abstract: One of the best methods for analyzing the fatigue properties, the dissipated energy (DE) approach was used to investigate the fatigue properties of the cement concrete bridge pavement in this paper. Based on the DE concept for asphalt mixture, the fatigue life equation is derived for cement concrete bridge pavement sustaining repeated cyclic load. The composite beam fatigue tests were conducted using a third-point flexural bending test to determine the dissipated energy parameters and the relevant regression coefficients, and then the fatigue lives of pavement under different axle loads can be predicted. On the basis of these works, the fatigue life predictive formula of pavement using DE approach is expressed as a relationship between the initial dissipated energy (W0) and the fatigue life (Nf). The results of this paper have strong theoretical and practical value in establishing the fatigue design theory and method for cement concrete bridge pavement and estimating effectively the service life of concrete bridge pavement.
  Authors: Qian, Zhendong; Wang, Jiangyang; chen, Leilei; Peng, Guangyin
  Authors: Qian, Zhendong; Wang, Jiangyang; chen, Leilei; Peng, Guangyin
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 288
  Paper Number: 13-3278
• Durability Investigation of High-Performance Concrete Mixtures with Quality Control and Quality Assurance
  Abstract: Durability investigation of concrete structures attracted significant attention in recent years to reduce the life cycle cost and increase the service life of new concrete structures. One of the possible solutions is to implement high-performance concrete (HPC) mixtures by using different types of slags, fly ashes, silica fume and other natural pozzolans as supplementary cementitious materials (SCMs) in bridge decks and other highway structures. This research examined 24 different binary and ternary based cementitious mixtures including the control mixture and evaluates some of their fresh properties namely slump, air content and temperature of concrete. The research evaluated compressive strength and electrical resistivity of hardened concrete using Wenner Probe device. Compressive strength and electrical resistivity were measured for several days to determine their variation and periodic gain over time for different cementitious mixtures. Theoretical charge passed on 56 days was also computed using Berke’s empirical approach and compared with 28 days electrical resistivity. Results show that compressive strengths of all mixtures with high SCM replacements meet most DOT’s specification of 4000 psi at 28 days except one mixture. Results also depicted that HPC mixtures have produced higher range of electrical resistivity at later ages and this component has a major role in the propagation stage of chloride induced corrosion process. Using different durability enhanced HPC mixtures with up to 50 to 55% ordinary cement replacements, the electrical resistivity data provides multiple options for long lasting bridge decks against chloride induced corrosion with less effort and expense.
  Authors: Ghosh, Pratanu; Le, Tuan; Cervetti, Thomas
  Authors: Ghosh, Pratanu; Le, Tuan; Cervetti, Thomas
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 287
  Paper Number: 13-3387
• Externally Bonded GFRP and NSM Steel Bars for Enhanced Strengthening of Concrete T-beams
  Abstract: The technology of FRP strengthening has matured to a great extent. However, there is always room for performance improvements. In this study, external bonding of GFRP and near surface mounting of regular steel bars is combined to improve the behavior, delay the failure and enhance the economy of the strengthening. E-Glass FRP is selected due to its inexpensive cost and non-conductive properties to shield the NSM steel bars from corrosion. On the other hand, the use of NSM bars gives redundancy against vandalism and environmental deterioration of GFRP. An experimental program is conducted in which four T beams are designed and built. The first beam is tested as a control beam failing at about 15 kips. The second beam is strengthened using 5 layers of CFRP, which failed at 25.5 kips by CFRP debonding. The third beam is strengthened using two #5 steel NSM bars and 1 layer of GFRP, both extending to the support. This beam failed at 38.4 kips by GFRP and NSM debonding. The fourth beam is strengthened with the same system used for the third beam. However, the NSM steel bars were cut short covering only 30% of the shear-span while the GFRP was extended to the support. This beam failed at 25.9 kips by GFRP debonding and NSM delamination due to the lack of sufficient development of the NSM steel bars and the shear stress concentration at the steel bar cut off point. Nevertheless, the failure load developed was comparable to 5 layers of CFRP used for beam 2.
  Authors: Traplsi, Abdelbaset; Wuertz, Augustine; Rasheed, Hayder; AlKhrdaji, Tarek
  Authors: Traplsi, Abdelbaset; Wuertz, Augustine; Rasheed, Hayder; AlKhrdaji, Tarek
  Year: 2013
  Document Type: Paper
  Subject: Bridges and Other Structures; Design; Materials
  Session: 461
  Paper Number: 13-3120
• Fatigue Properties of Asphalt Materials at Low In-ServiceTemperature
  Abstract: Fatigue damage is one of the most common distresses observed on the asphalt concrete pavement.To thoroughly understand the fatigue of asphalt concrete, the behaviors of the major componentsof asphalt concrete under cyclic loading are investigated in this study. A new experimentalmethod is developed to evaluate the performances of asphalt binder, mastic and fine aggregatesmixture under cyclic loading. The test results show that the fatigue performance of asphalt binderis closely related with loading magnitude, temperature and loading frequency. Mastic specimenswith varied filler content are tested and the results indicate that the mastic specimen with 30%filler content has better fatigue resistance. The micro-structure analysis of mastic and mixtureindicates that the fatigue resistance is closely related with the air void content of specimen. 3-Ddigital specimens and tests of asphalt binder, mastic and mixture are developed based on thefinite element method (FEM). With proper selection of damage model parameters, the simulationresults agree well with lab test results and can be used as a basis for future fatigue research.Finally, the reinforcement effect of basalt fiber is evaluated as an additive to improve the fatigueresistance of asphalt binding materials. It is found that with proper content, the fatigueresistances of asphalt binder and mastic are significantly improved. The numerical simulationanalysis also shows that the fiber added between fillers releases the stress concentration in theinterface area and diminishes the fatigue damage caused by cyclic loading.
  Authors: Wang, Dong; Wang, Linbing; Zhou, Guoqing; Druta, Cristian
  Authors: Wang, Dong; Wang, Linbing; Zhou, Guoqing; Druta, Cristian
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 653
  Paper Number: 13-3230
• Newark Airport Runway: Forensic Study Revisited
  Abstract: Loose aggregate raveling from a runway surface creates risk for foreign object damage. To reduce the probability for surface raveling and cracking, engineers often use polymer-modified asphalt (PMA), which has been widely shown to reduce pavement surface damage. Unfortunately, every paradigm of paving has exceptions, including performance expectations for PMA. When two different high-quality PMA products raveled before the conventional section on a major runway at Newark Airport, significant forensic analysis was warranted. Numerous binder and mixture properties were evaluated, with particular emphasis on moisture damage and accelerated aging coefficients that might indicate binder hardening or embrittlement. The initial (2004) forensic analysis of these five-year-old pavements eliminated moisture damage as the cause, and focused primarily on binder aging. Although significant increases in binder and mixture moduli were noted near the surface as the pavement aged, there were no definitive failure criteria that could be directly tied to the initiation of raveling or surface cracking. This older forensic study is revisited to evaluate the recently proposed Glover-Rowe parameter as a predictor of age-induced surface damage. This damage index, which is easily measured in a DSR at intermediate temperatures, has been proposed as a materials indicator for timing pavement preservation strategies. For this very limited field study, the Glover-Rowe parameter correctly predicts the unexpected onset of raveling for the two PMA sections, as well as the good performance of the conventional section, whereas other common aging/cracking parameters fail to rank the materials correctly. Further field validation of this parameter is recommended.
  Authors: King, Gayle Nathaniel; Rowe, Geoffrey M.; Reinke, Gerald H.
  Authors: King, Gayle Nathaniel; Rowe, Geoffrey M.; Reinke, Gerald H.
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 655
  Paper Number: 13-3050
• Field Monitoring of Fatigue Crack on Highway Steel I-Girder Bridge
  Abstract: This paper presents a field test program for fatigue crack monitoring on a steel I-girder bridge located in a busy highway route in Maryland. Acoustic emission (AE) monitoring of an existing fatigue crack on the connection plate was performed using piezoelectric film AE sensor and laser sensor was used to continuously measure the differential deflection between two adjacent girders. The triggered AE signals measured by the piezoelectric film AE sensors are presented and are believed to be associated with fatigue crack related AE events.
  Authors: Zhang, Yunfeng; Zhou, Changjiang; Fu, Chung C.; Zhou, Ed
  Authors: Zhang, Yunfeng; Zhou, Changjiang; Fu, Chung C.; Zhou, Ed
  Year: 2013
  Document Type: Paper
  Subject: Bridges and Other Structures; Maintenance and Preservation; Materials
  Session: 401
  Paper Number: 13-4097
• Rapid Displacement Monitoring Using Wireless Hybrid Sensor on In-Service Highway Bridge
  Abstract: Condition assessment and monitoring of bridges is critical for safe passenger travel, public transportation, and efficient freight. One of the most important parts of a bridge is the expansion joint, which accommodates continuous cyclic thermal expansion of the whole bridge. Conventionally, the displacement of the expansion joints is measured using wired sensors including LVDT, laser displacement transducer, etc. However, implementation of the wired displacement sensors is expensive due to the high cost of the data acquisition system, and time consuming cable installation. To overcome the challenges, a wireless smart sensor network (WSSN) has recently drawn significant attention as an alternative for transportation infrastructure monitoring. The main merits of WSSN are low cost, wireless communication capability, and versatile on-board computation. In this paper, a rapid wireless displacement monitoring system has been developed. This system, named wireless hybrid sensor (WHS), combines a high-resolution analog displacement sensor, a microprocessor, and a wireless multi-scale sensor board for accurate displacement monitoring. The WHS has been calibrated for both static and dynamic displacement measurement in the laboratory environment, and deployed on an in-service highway bridge to demonstrate rapid expansion joint monitoring. The test-bed is a continuous steel girder bridge, the Founders Bridge, in East Hartford, Connecticut. Using the WHS system, the static and dynamic displacement of the expansion joint has been successfully measured. With the WHS system, approximately 6% of the time was spent on installation and 94 % for the measurement.
  Authors: Jang, Shinae; Dahal, Sushil; Li, Jingcheng
  Authors: Jang, Shinae; Dahal, Sushil; Li, Jingcheng
  Year: 2013
  Document Type: Paper
  Subject: Bridges and Other Structures; Maintenance and Preservation; Materials
  Session: 401
  Paper Number: 13-4110
• Is Atomic Force Microscopy Suited as Tool for Fast Screening of Bituminous Materials? Interlaboratory Comparison Study
  Abstract: Bituminous binders are known to have microstructures at typical length scales of micrometers. This microstructure can be probed with Atomic Force Microscopy (AFM). Now that worldwide several research groups are reporting AFM results on bitumen, it is becoming important to improve the understanding of the reproducibility and objectivity of the technique for studying bituminous samples. When reproducibility and stability are proven, AFM can be a tool for asphalt professionals to rapidly screen bituminous binders. In this context two independent laboratories have developed a standard method for preparing and conditioning bitumen for AFM imaging. By means of an inter-laboratory comparison of independently imaged specimen, the reproducibility of microstructure measurements was investigated. A quantitative comparison on different microstructures was developed, and the consistency of independently obtained results was confirmed. The results from both labs were comparable: the microstructural properties were found to be randomly distributed within a 5% interval. Also the influence of temperature on the microstructure was demonstrated to be reproducible and consistent. With the increase of temperature, the microstructure gradually disappeared, however traces of the microstructure remained visible up to the highest measurement temperature of 60°C. It is concluded that given well defined sample preparation and measurement procedures, the microstructure of bitumen can be reproducibly imaged by AFM from room temperature up to temperatures where bitumen becomes liquid.
  Authors: Nahar, Sayeda Nowrozon; Dillingh, Bert; Erkens, Sandra; Fischer, Hartmut; Schitter, Georg
  Authors: Nahar, Sayeda Nowrozon; Dillingh, Bert; Erkens, Sandra; Fischer, Hartmut; Schitter, Georg
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 604
  Paper Number: 13-4131
• Experimental Evaluation of Connections in Hybrid FRP-Concrete Bridge Truss Girders
  Abstract: An innovative corrosion-free precast prestressed concrete truss girder has been developed for short- and medium-span slab-on-girder bridges. The girder consists of top and bottom concrete flanges connected by precast vertical and diagonal members made of fiber reinforced polymer (FRP) tubes filled with concrete. The verticals and diagonals are connected, respectively, to the concrete flanges by means of glass FRP dowels and stud reinforcement made of corrosion-resistant steel or FRP material. The flanges are pretentioned with carbon FRP tendons. The deck slab is reinforced with corrosion-resistant steel bars in the bottom transverse layer and with glass FRP bars in the bottom longitudinal and the top layers. The girders may be post-tensioned with external carbon FRP tendons to balance the slab weight and to provide continuity in multi-span bridges. The new system has the advantages of light weight and enhanced durability. The light weight reduces the initial cost and allows for longer spans. The improved durability reduces the maintenance cost and extends the structure’s life span. This paper describes the general details of the system and presents an experimental evaluation of its critical components, namely, the FRP tubes and the truss connections. Two types of FRP tube and four types of connection are investigated. Results of testing eight connection specimens under static loading and four specimens under fatigue are presented. The tests have shown excellent performance of the connection when filament wound tubes and continuous double-headed studs are used.
  Authors: El-Badry, Mamdouh; Schonknecht, Kyle; Abe, Hiroyuki
  Authors: El-Badry, Mamdouh; Schonknecht, Kyle; Abe, Hiroyuki
  Year: 2013
  Document Type: Paper
  Subject: Bridges and Other Structures; Design; Materials
  Session: 461
  Paper Number: 13-4134
• Obtaining Nanorheology of Asphalt Binders Using Atomic Force Microscope and Modified Fischer-Cripps Solution
  Abstract: During the last few years several researchers have used the Atomic Force Microscope (AFM) to visualize the microstructure of asphalt binder and also to evaluate the influence of aging, nanomodification, and thermal history on this microstructure. More recently, owing to the low stiffness of asphalt binders, researchers have used the AFM to perform nano-indentation on asphalt binders. This paper presents and exemplifies the use of modified analytical solutions to determine the nano-rheology of asphalt binders using the AFM as a nano indenter. More specifically the solution presented is based on a corrected Fischer-Cripps viscoelastic spherical indentation solution. AFM indentations were performed on asphalt thin film using a conospherical tip, and the analytical solutions were used to determine the creep compliance parameters with minimal error. The results and methodology presented in this paper can be used to determine the time dependent behavior of microphases within the asphalt binder, to study the effect of modifiers such as polymers or other organic additives on the nanorheology of asphalt binder, and to obtain mechanical properties required for computational micro-mechanics of asphalt binders at a micrometer length scale.
  Authors: Jahangir, Rezwan; Allen, R. Grover; Little, Dallas N.; Bhasin, Amit
  Authors: Jahangir, Rezwan; Allen, R. Grover; Little, Dallas N.; Bhasin, Amit
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 604
  Paper Number: 13-4144
• Compressive Stress-Strain Behavior of Ultra-High-Performance Concrete Using Local Materials
  Abstract: As the U.S. faces the challenge of its aging infrastructure, considerations of sustainability and durability to protect the environment, while providing confidence in the mitigation of natural and man-made hazards, must be a priority. Ultra High Performance Concrete (UHPC) has several benefits that provide solutions to these current challenges. With its high compressive strengths, improved tensile strength, and toughness, UHPC offers many advantages including: reduced material quantities; smaller geometry of members; and improved durability; all while increasing the safety and security of the structure. With these characteristics, UHPC is an innovative material that has the potential to influence structural design in the transportation industry domestically and globally.The use of this material has been limited by a lack of design codes and the high cost associated with the material. At New Mexico State University, more economical mixture proportions using materials local to the region have been developed. To better understand the material and aid in the development of design tools, the material properties of the UHPC using local materials were investigated. Cube specimens were tested in compression to determine the stress-strain relationship and the modulus of elasticity for the UHPC using local materials. The results were compared to three equations from literature to estimate the modulus of elasticity of UHPC based on compressive strength. It was observed that the local material constituents play a significant role in the concrete compressive strength and material properties for UHPC using local materials.
  Authors: Guaderrama, Lucas Rivas; Weldon, Brad
  Authors: Guaderrama, Lucas Rivas; Weldon, Brad
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 286
  Paper Number: 13-3339
• Dynamic Testing of Civil Engineering Materials Using Split-Hopkinson Pressure Bar
  Abstract: The Split-Hopkinson Pressure Bar (SHPB) is a tool used to assess dynamic material properties at strain rates up to approximately 1,000 1/s. Originally developed for the testing of metals over 100 years ago, modifications now allow testing of other materials. This paper will provide results from a wide range of materials used in transportation such as wood, concrete, and sedimentary rock. The basic components of a standard SHPB consist of a cannon, striker bar, input bar, and an output bar. A cannon uses compressed gas to fire a striker bar into the input bar of the SHPB. The sample is placed between the input and output bars prior to firing the cannon, and strain gages on the two bars are used to measure the input pulse, along with the reflected and transmitted pulses. The resulting data can be used to determine the dynamic stress/strain response in compression at high rates of strain through one-dimensional wave theory.Specimens were tested using a 3-inch (76-mm) diameter SHPB. The overall function of the SHPB along with test results will be discussed. Wood, specifically hard maple specimens, consisting of sugar maple (Acer saccharum) and black maple (Acer nigrum), and eastern white pine (Pinus strobus) specimens were tested. Tests were also performed on 18-year old Portland cement concrete pavement cores along with rock cores from the Nonesuch Shale formation comprised of a very uniform siltstone. The SHPB was found to be a useful tool for assessing the dynamic stress/strain curves of these materials.
  Authors: Gilbertson, Christopher Glenn; Vitton, Stanley James
  Authors: Gilbertson, Christopher Glenn; Vitton, Stanley James
  Year: 2013
  Document Type: Paper
  Subject: Geotechnology; Materials
  Session: 291
  Paper Number: 13-3380
• Using Poker Chip Test for Determining Bulk Modulus of Asphalt Binders
  Abstract: The properties of asphalt binders strongly influence the overall mechanical response of asphalt mixture composites. A thorough understanding of the mechanistic behavior of asphalt binders is important in order to fully and accurately characterize the behavior of the asphalt mixture. The mechanical properties of the asphalt binder, the matrix in the asphalt mixture composite, are time and temperature dependent and have a lower stiffness compared to the inclusions (aggregate particles). However, computational methods used to model the micromechanics of asphalt mixtures typically assume a constant bulk modulus or Poisson’s ratio for asphalt binders. This study investigates the time-dependence of the bulk modulus of an asphalt binder. Several approaches for measuring the bulk modulus were explored and the poker-chip geometry was found to be the most suitable one. The boundary value problem for the poker-chip geometry was solved to determine the bulk modulus and Poisson’s ratio of an asphalt binder as a function of time. The findings from this research improve the understanding of asphaltic materials behavior, and also guide important assumptions typically made during computational modeling of asphaltic materials.
  Authors: Motamed, Arash; Bhasin, Amit; Liechti, Kenneth M.
  Authors: Motamed, Arash; Bhasin, Amit; Liechti, Kenneth M.
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 604
  Paper Number: 13-3480
• Laboratory HMA Cracking Testing: Evaluation of Three Repeated Loading Crack Tests
  Abstract: Cracking is one of the predominant distresses occurring in hot-mix asphalt (HMA) pavements, often costing the highway agencies millions of dollars in road maintenance and rehabilitation activities. One way to minimize this distress is through material screening and selection of appropriate mix-designs that are representative of crack-resistant HMA mixes. However, there are no universally adapted standardized laboratory cracking test methods for routine mix-design and/or screening purposes for HMA mix crack-resistance. In this study, three different repeated loading cracking test methods, namely the repeated loading Overlay Tester (OTR), repeated loading indirect-tension (R-IDT), and repeated loading semicircular bending (R-SCB), were comparatively evaluated for their potential application as surrogate tests for routine crack evaluation and screening of HMA mixes in the laboratory. The evaluation criteria, based on commonly used Texas HMA mixes, included: (1) potential to readily differentiate and screen mixes, (2) sensitivity to mix-design variables such as variations in the asphalt-binder content (AC), (3) repeatability and statistical variability, (4) correlation to field performance data, and (5) practicality of implementation. Overall, the OTR test, with a proven correlation to field performance data, exhibited statistical superiority as a practical repeated loading crack test method for routine HMA mix-design and screening, seconded by the R-IDT test. However, while the R-IDT test exhibited superiority in terms of sample fabrication simplicity, validation with field data remains one of the key challenges to be addressed with this test. The R-SCB test was the least repeatable, particularly at high AC levels and appears to be better suited for low temperature testing.
  Authors: Walubita, Lubinda F.; Faruk, Abu Nayeem Md.; Alvarez, Allex E.; Izzo, Richard; Haggerty, Brett; Scullion, Tom
  Authors: Walubita, Lubinda F.; Faruk, Abu Nayeem Md.; Alvarez, Allex E.; Izzo, Richard; Haggerty, Brett; Scullion, Tom
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 653
  Paper Number: 13-3495
• Influence Of Aggregate Source On The Properties Of Wma Mixtures In South Dakota
  Abstract: This study evaluated the impact of three aggregate sources (Limestone, Quartzite and Natural Gravel) and three different WMA processes (advera, evotherm, and plant foaming) on the properties of asphalt mixtures from South Dakota (SD). Moreover, the WMA mix design as proposed by NCHRP 9-43 was implemented. The aggregate source and warm-mix process were found to have impact on the mixing and compaction temperatures of the WMA mixture. The performance of the WMA mixtures was evaluated in terms of moisture damage, rutting, thermal; cracking, and fatigue cracking resistance. Aggregate source, WMA additive type, and the interaction between the two were shown to have moderate to significant effects on the performance of the asphalt mixtures for certain tests, while having no effect for other tests. Statistical differences were found when comparing indirect tensile strength and tensile strength ratio values, Flow Number, Asphalt Pavement Analyzer rut depth, and fatigue cracking test results for the various mixtures. None of the WMA mixtures performed as well as the HMA, except in the beam fatigue test. This was mainly related to the difference between the HMA and WMA short-term aging procedures. However, WMA mixtures exhibited similar or higher moisture damage, rutting, and fatigue cracking resistance than the HMA mixtures produced at the WMA temperatures or with two hours short-term conditioning instead of the recommended four hours by Superpave. Dynamic modulus results showed that, on average, WMA mixtures had significantly lower dynamic modulus values than the HMA mixtures, but similar values to HMA mixtures produced at the WMA temperature and short-term conditioning. The Thermal Stress Restrained Specimen Test (TSRST) showed that the reduction of production temperatures and short-term aging lowered the fracture temperature while it did not impact the fracture stress. The impact of WMA additives on thermal cracking and fatigue characteristics depended on the type of aggregate.
  Authors: Ahmed, Taha; Hajj, Elie Y; Sebaaly, Peter E.; Majerus, Nate
  Authors: Ahmed, Taha; Hajj, Elie Y; Sebaaly, Peter E.; Majerus, Nate
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 597
  Paper Number: 13-3501
• Effects of Shear Stress on Pavement Cracking and Interface Debonding: Case Study in Arkansas
  Abstract: Longitudinal cracking in wheelpaths and interface debonding at 2 inches underneath the surface were observed on Interstate 40 in Franklin County, Arkansas. Besides the mostly known reason, construction deficiency, this study investigated this problem from the perspective of shear stress. 3D finite element model was developed to predict structural responses for different scenarios by varying the thickness of the wearing course, the horizontal loads level, the stiffness ratio and interface condition between the wearing course and its underlying layer. Results showed that the location of the maximum shear stress was constantly between 4cm and 6cm below the surface when the horizontal force was in a low level. Much greater than tensile stresses, shear stresses at the edge of tires contributed greatly to the initiation of the longitudinal cracking in wheelpaths. In addition, it was found that the maximum shear stress took place at the interface when the interface between the wearing course and the binder course was not fully bonded. Thus, the interface could suffer large repeated shear stresses and lead to fatigue cracking in the asphalt mixture. In summary, this study concluded that shear stress at the interface could be a significant factor responsible for pavement cracking and interface debonding.
  Authors: Zou, Xiaoling
  Authors: Zou, Xiaoling
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 840
  Paper Number: 13-3506
• Crack Propagation Model for Asphalt Mixtures Based on Cyclic Semicircular Bending Test
  Abstract: While the use of Semi-Circular Bending (SCB) test has been successful to characterize the fracture resistance of HMA, only limited attempts were found in the literature to assess the fatigue resistance of HMA in the laboratory using this geometry. The objective of this study is twofold. First, a fatigue crack propagation model was developed to predict the number of cycles to failure based on a cyclic SCB test and the generalized J-integral approach. Second, the effect of creep deformation on the SCB test results obtained at intermediate temperature was investigated. To achieve these objectives, the necessary theoretical formulation is introduced based on fracture mechanics principles. Results of the model were validated based on laboratory testing of asphalt mixtures using cyclic SCB tests. Results of this study showed good agreement between experimental and model predicted SCB test results. Based on these results, it is determined that the proposed model provides an acceptable representation of the experimental fatigue SCB test. Evaluation of the creep deformation in the monotonic SCB test showed that the average energy dissipated due to creep deformation in the SCB test was 7.1% of the total dissipated energy predicted by the model. This means that 92.9% of the energy is dissipated due to the propagation of the crack in the SCB test. Therefore, the dissipated energy due to fracture is the predominant factor controlling failure in the SCB test.
  Authors: Ying, Hao; Elseifi, Mostafa A.; Mohammad, Louay N.; Aglan, Heshmat
  Authors: Ying, Hao; Elseifi, Mostafa A.; Mohammad, Louay N.; Aglan, Heshmat
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 653
  Paper Number: 13-3515
• Investigation of Recycled Building Materials for Flexible Pavement Mixes in Egyptian Low-Volume Roads
  Abstract: The deposition of demolished concrete from old building structures in landfills is currently an unacceptable strategy because of the increasing cost of disposal, the declining availability of disposal space, and other environmental concerns. Recycling of old building structures as construction materials is a viable alternative. The objectives of this research study are to investigate the feasibility of using Recycled Building Materials in asphalt pavement mixes. Two types of Recycled Building Materials, Recycled Bricks (RB) and Recycled Concrete (RC) were used as coarse aggregates in Hot Mix Asphalt of Low Volume Roads in Egypt. A total of nine hot asphalt mixtures were formed by replacing certain percent of the coarse virgin aggregates by crushed bricks and concrete. The prepared mixtures were tested in Marshall, immersion, indirect tensile, and creep tests to investigate the effect of recycled materials on mixture properties and identify the optimum percentage of recycled materials.The findings in this project support the hypothesis that both RC and RB can be used effectively as a coarse aggregate in HMA when appropriate quality control techniques are utilized. Based on the information obtained in this study, the recycled building materials could be used as partial replacement of coarse virgin aggregates in HMA without significant reduction in its performance.
  Authors: Mahgoub, Hesham; Mohamady, Ahmed; Abdel-Motaleb, Mohammed
  Authors: Mahgoub, Hesham; Mohamady, Ahmed; Abdel-Motaleb, Mohammed
  Year: 2013
  Document Type: Paper
  Subject: Geotechnology; Materials; Pavements
  Session: 284
  Paper Number: 13-3526
• Comprehensive Evaluation of Polymer-Modified SMA Mixture Produced with New Polyethylene Wax-Based WMA Additive with Adhesion Promoter
  Abstract: The use of polymer-modified stone mastic asphalt (PSMA) is increased in highway and expressway because it provides high rutting resistance, a good skid resistance and noise reduction for heavily trafficked roads. However, PSMA mixture requires high mixing and compacting temperatures to create a suitable coating between polymer-modified asphalt and large size of aggregate. Warm-mix asphalt (WMA) technology is being used in polymer-modified asphalt (PMA) mixture to reduce mixing and compacting temperatures. A new polyethylene wax-based WMA additive with adhesion promoter was selected to use in PSMA mixtures at significantly lower temperature than a conventional PSMA mixture. In this study, the performance characteristics of PSMA mixture using new polyethylene wax-based WMA additive (PSMA-WMA) are evaluated against a conventional PSAM mixture without additive (PSMA-HMA) in terms of the moisture susceptibility, viscoelastic properties, rutting resistance at high temperature, fatigue resistance and crack resistance at low temperature. The mix design is carried out in the laboratory for the conventional PSMA-HMA mixture and a similar composition was adopted for the PSMA-WMA mixture (with the incorporation of 1.5% WMA additive in the bitumen) in order to evaluate the influence of polyethylene wax-based additive on the performance characteristics of the resulting mixture. Drain-Down and Cnatabro test results of PSMA-WMA mixture meets the requirement of criterion. Based upon the comprehensive evaluation of PSMA-WMA mixture against PSMA-HMA mixture, it is concluded that the performance characteristics of the PSMA-WMA mixture are better than those of the PSMA-HMA mixture in the moisture susceptibility, rutting resistance at high temperature, fatigue resistance at intermediate temperature and crack resistance at low temperature. Thus, new polyethylene wax-based WMA additive is effective on reducing the production temperature without compromising the performance of PSMA-WMA mixture.
  Authors: Kim, Yongjoo; Lim, Jaekyu; Lee, Munsup; Kwon, Soo-Ahn; Hwang, Sungdo; Wei, Liu
  Authors: Kim, Yongjoo; Lim, Jaekyu; Lee, Munsup; Kwon, Soo-Ahn; Hwang, Sungdo; Wei, Liu
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 597
  Paper Number: 13-3530
• Establishment of Universal Healing Evaluation Index for Asphalt Binder
  Abstract: The healing performance of asphalt binder is important to the overall performance of asphalt pavement. A suitable healing evaluation index is critical in order to compare the healing performance of different asphalt binders and choose the binder with the best healing properties. However, current studies focus primarily on the healing performance of asphalt binder and seem to ignore the importance of a healing evaluation index. In this paper, the healing performance of four different asphalt binders is analyzed. By comparing the healing curve the initial curve, a ratio that is based on the areas created by the curves is found to reflect the healing performance of the asphalt binder. Once the healing evaluation indices are established, they are used also to evaluate the mastics, and the applicability of the indices is analyzed. Also, a healing function for asphalt binder is established. The results show that the HIm-c index (based on the curve of the normalized modulus versus load cycles), the HIem-c index (based on the curve of the elastic modulus versus load cycles) and the HIvm-c index (based on the curve of the viscous modulus versus load cycles) suggest the same rankings for the healing of the study binders. The healing ranking of the binders is also the same as that of the corresponding mastics evaluated by the HIm-c index. Based on the established healing function, it is found that the effect of terminal cases on the healing performance of asphalt binder is greater than the effect of rest periods.
  Authors: Shan, Liyan; Yiqiu, Tan; Kim, Y. Richard; Xu, Yongli
  Authors: Shan, Liyan; Yiqiu, Tan; Kim, Y. Richard; Xu, Yongli
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 374
  Paper Number: 13-3587
• Flexural Behavior of Hybrid FRP-Ultra-High-Performance Fiber-Reinforced Concrete Composite Beams
  Abstract: This paper presents the development of a new composite beam consisting of a hybrid CFRP/GFRP I-beam and precast Ultra-High Performance Fiber Reinforced Concrete (UHPFRC) slab. Hybrid FRP (HFRP) provides the advantage of high corrosion resistance while UHPFRC has high strength and durability. The combination of these two materials is expected to benefit structures subjected to severe environmental conditions and wherever there is a need for accelerated bridge construction. Three full-scale composite beams with varying UHPFRC slab width were tested under four point flexural loading. Bolt shear connectors with/without epoxy bonding were used in the tested beams. The bolt shear connectors and epoxy were used to resist the horizontal shear flow at the interface between the HFRP I-beam and the UHPFRC slab. The composite action between the HFRP I-beam and UHPFRC slab was investigated. The test results showed that all the composite beams exhibited significant improvements in stiffness and strength properties, above those of simple HFRP I-beam without UHPFRC slab. A fiber model was developed to predict the strength and stiffness of the tested beams and the model accuracy was verified. A fairly good agreement between the experimental and analytical results was found. High tensile strength of the CFRP in the HFRP tensile flange can be effectively utilized and delamination failure of the HFRP compressive flange can be prevented by addition of the UHPFRC slab on the top flange of the HFRP I-beam. The study revealed that HFRP-UHPFRC beams are efficient and can provide a very competitive, cost-effective and sustainable solution to bridge structures.
  Authors: Nguyen, Hai D.; Hiroshi, Mutsuyoshi; Zatar, Wael A.
  Authors: Nguyen, Hai D.; Hiroshi, Mutsuyoshi; Zatar, Wael A.
  Year: 2013
  Document Type: Paper
  Subject: Bridges and Other Structures; Design; Materials
  Session: 461
  Paper Number: 13-3699
• Local Practice of Assessing Dynamic Modulus Properties for Washington State Mixtures
  Abstract: Dynamic Modulus (|E*|) is one of the key elements of a mechanistic-empirical based flexible pavement design procedure. It is used to characterize the material properties of asphalt mixtures and determine the stress-strain responses of a pavement at different loading conditions. Dynamic modulus is also a direct input parameter in several pavement performance models to estimate the field fatigue cracking and rutting performance. To provide a better understanding of the local materials, this study aims to test the typical asphalt mixtures used by Washington State Department of Transportation (WSDOT) and establish a material catalog for dynamic modulus. In this study, seven plant produced mixtures from five regions of Washington State were sampled and tested. These mixtures represent the typical asphalt binder, gradation, and mix designs of the state. One warm mix asphalt (WMA) project was also included in the analysis. Based on the experimental results, it was found that mix properties including air voids and binder properties had an important impact on the dynamic modulus. Due to the limited aggregate gradations, the effect of aggregate gradation on dynamic modulus was inconclusive. The measured dynamic modulus data were compared to the prediction results using the traditional Witczak E* model, the new Witczak E* model, and the Hirsch model. The Hirsch model was found to be the most promising and was further modified by including mastic property into the model. The modified Hirsch model greatly improved prediction quality and can be used as both a design tool and a screening tool to estimate the dynamic modulus of a mixture at early stages of the mix design process.
  Authors: Shen, Shihui; Yu, Huanan; Willoughby, Kim A.; DeVol, Joseph R.; Uhlmeyer, Jeffrey S.
  Authors: Shen, Shihui; Yu, Huanan; Willoughby, Kim A.; DeVol, Joseph R.; Uhlmeyer, Jeffrey S.
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 826
  Paper Number: 13-4181
• Aging Characteristics of RAP-Modified Binders: Rheological Properties
  Abstract: A study involving two RTFO-aged asphalts and their blends with 15 and 50 percent of extracted RAP binders was conducted to investigate the effect of RAP content and properties on the long-term aging characteristics of asphalt binders. This paper presents the influence of RAP binders on the rheological properties of fresh binders in terms of their aging characteristics. The results from rheological analyses of aged blended binders indicate that the aging characteristics of blended binders are dependent on fresh asphalt binders. The results show the crossover frequency decreases as RAP concentrations increase and the rheological index increases as RAP concentration increases. The pattern for stiffness increase as a function of aging times for RAP blended binders is similar to that of typical chemical aging kinetic model, where the stiffness increases substantially initially and then levels off at longer aging times. The results demonstrate that there is a linear relationship between the logarithm of G* and phase angle for RAP blended binders at all aging times and RAP contents, regardless of asphalt and RAP sources.
  Authors: Huang, Shin-Che; Turner, Thomas F
  Authors: Huang, Shin-Che; Turner, Thomas F
  Year: 2013
  Document Type: Paper
  Subject: Materials; Pavements
  Session: 307
  Paper Number: 13-4226
• Evaluating Effects of Ground Tire Rubber-Modified Asphalt and Dry Added Treated GTR on Performance Characteristics of RAP Mixtures
  Abstract: One approach to reduce the cost of asphalt mixtures and to produce environmentally friendly mixtures is to use more readily available recycled materials like Reclaimed Asphalt Pavements (RAP) and Ground Tire Rubber (GTR).In this study, GTR and Treated GTR were added to binder and to high RAP content mixtures. Rutting performance of the binders was evaluated by conducting the Multiple Stress Creep Recovery test, fatigue performance was evaluated by the Linear Amplitude Sweep test, and the degree of separation was measured by conducting the Cigar Tube Test . Also, the effect of a suspension agent on the degree of separation was determined. GTR and Treated GTR significantly improved the rutting and fatigue performance of the asphalt binders. The suspension agent successfully decreased the degree of separation between rubber particles and binder.GTR was introduced into the binder and the resulting rubberized binder was used to design a 9.5 mm Superpave mixture. The Treated GTR was directly added to the mixture. Treated GTR mixtures were mixed and compacted at lower temperatures compared to GTR mixtures. The dynamic modulus was determined using the Asphalt Mixture Performance Tester, reflective cracking performance was evaluated using the Texas Overlay Tester, low temperature cracking resistance was evaluated by the Thermal Stress Restrained Specimen Test, and rutting and moisture susceptibility was evaluated using the Hamburg Wheel Tracking Device.GTR and Treated GTR made the mixtures slightly more prone to reflective cracking, but improved their resistance to rutting, moisture susceptibility, and low temperature cracking.
  Authors: Vahidi, Siavash; Mogawer, Walaa S.; Booshehrian, Abbas
  Authors: Vahidi, Siavash; Mogawer, Walaa S.; Booshehrian, Abbas
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 656
  Paper Number: 13-4248
• Effects of Changing Virgin Binder Grade and Content on RAP Mixture Properties
  Abstract: Most highway agencies have decades of experience with HMA containing low to moderate percentages of reclaimed asphalt pavement (RAP) because the general perception that RAP mixtures may be more susceptible to various modes of cracking. As the RAP proportion increases there is the potential for an increase in mixture stiffness and decrease in resistance to cracking. Two options for increasing the durability of RAP mixtures proposed have been increasing the amount of virgin binder in the asphalt mixture or decrease the performance grade of the virgin binder. To assess these options, 0, 25 and 50 percent RAP mixtures at optimum asphalt content were designed using a standard PG 67-22 virgin asphalt binder. These mixtures were tested to evaluate the surface cracking, reflection cracking, and rutting using the energy ratio (ER), overlay tester (OT), and asphalt pavement analyzer (APA), respectively. These tests were also conducted on the RAP mixtures with 0.25% and 0.50% higher asphalt contents and at the optimum asphalt content using a softer virgin binder. Additionally, the linear amplitude sweep (LAS) methodology was used to assess the fatigue properties of the blended binders. The results show to improve cracking resistance increase the amount of virgin asphalt by 0.1 percent for every 10 percent of RAP binder in the mixture for up to 30 percent RAP binder. When the RAP binder exceeds 30 percent, a softer grade of asphalt should be used to increase the mixture’s resistance to cracking. All mixtures should be assessed for rutting susceptibility.
  Authors: Willis, James Richard; Turner, Pamela; Padula, Flávio Renato de Góes; Tran, Nam; Julian, Grant
  Authors: Willis, James Richard; Turner, Pamela; Padula, Flávio Renato de Góes; Tran, Nam; Julian, Grant
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 656
  Paper Number: 13-4256
• Importance of Insulation at Bottom of Mass Concrete Placed on Soil
  Abstract: Many a times, when mass concrete is placed directly on top of a soil layer, an insulation layer is not used at the bottom of the concrete. The rationale for this practice is that the soil on which the concrete is placed is already an insulating material. This study investigated the question of whether or not the absence of an insulating layer between the mass concrete and the soil may cause a problem with cracking of the concrete at early age. A three-dimensional finite element model was used for this investigation. The soil layer beneath the concrete was modeled to simulate realistic heat transfer between the concrete and the soil. To validate the developed model, a bridge pier footing constructed in the field in Florida was monitored for temperature development, and compared with the computed temperature distribution from the finite element model. The results show that the temperatures predicted by the model closely agree with those measured in the field. A parametric analysis was also conducted to determine the effects of insulation on the temperature distribution, induced tensile stresses and the cracking risk in the mass concrete. From the thermal cracking analysis, it is concluded that full insulation with adequate thickness should be used to reduce the temperature differentials and prevent cracking during the early age hydration of mass concrete.
  Authors: Do, Tu; Lawrence, Adrian M.; Tia, Mang; Bergin, Michael
  Authors: Do, Tu; Lawrence, Adrian M.; Tia, Mang; Bergin, Michael
  Year: 2013
  Document Type: Paper
  Subject: Construction; Materials; Pavements
  Session: 427
  Paper Number: 13-4257
• Modification of Particulate Additive Test for Determination of Styrene Butadiene Rubber Polymer Content of Asphalt Binders
  Abstract: As it is in many countries, Costa Rica is implementing the use of polymer modified asphalts for road construction. A growing market offers various types of polymers that significantly improve the rheological properties of the asphalts, like SBR, SBS, rubber, EMA, EVA among others, which are commonly added at percentages between 1 and 5% mass / mass of binder. However, little research has been conducted on quantifying the amount of polymer incorporated to the asphalt binders.This study presents a modification to the Particulate Additive Test (PAT) proposed by Bahia et al. (2001) to determine in a qualitative and quantitative way the presence of SBR type polymers on local asphalts (PG64-22). Two types of SBR polymers were used. However, the scope of this methodology does not include the identification of SBS polymers.The results obtained show an acceptable rate of polymer recovery. The results can be later verified by means of the Fourier Transform Infrared Spectroscopy (FTIR). Also the solvents can be changed to apply this method for SBS type polymers or other polymers, turning this method into a quick, easy and low cost quality control tool to verify the amount of polymer added to the plant asphalt mixtures.
  Authors: Corrales-Azofeifa, Jose; Salazar, Jorge; Aguiar-Moya, José Pablo; Loria-Salazar, Luis
  Authors: Corrales-Azofeifa, Jose; Salazar, Jorge; Aguiar-Moya, José Pablo; Loria-Salazar, Luis
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 604
  Paper Number: 13-4275
• Effect of Water Conditioning for Extended Periods on Properties of Asphalt Binders
  Abstract: The selection of materials that are less susceptible to moisture damage (i.e., stripping) is critical to guarantee the performance of asphalt pavements. Stripping in the asphalt mix can accelerate damage and consequently reduce pavement life. Most of the current research on moisture damage is related to the effect of water on the mastic, the aggregate, and the adhesive bond between the aggregate and the binder. However, limited research has been conducted to determine the effect of extended water exposure on the properties of asphalt binders. This paper investigates the influence of extensive water exposure on the stripping potential of asphalt binders by measuring rheological properties, bond strength and the wettability of a Colombian binder before and after immersion in water for three, six, and nine months. In this study, thin films of asphalt (i.e., height= 2 mm) were immersed in water for three, six, and nine months and comparisons were made between experimental results of unconditioned and conditioned binders. Master curves for complex modulus and phase angle were obtained using frequency sweep test in the Dynamic Shear Rheometer (DSR). The bond strength between the binder and aggregates was measured with the recently developed Binder Bond Strength (BBS) test. The wettability potential of the conditioned and unconditioned binder was estimated using the Sessile Drop method. Further, Dynamic Modulus testing of mixes prepared with the unconditioned and conditioned binder was conducted. Experimental results indicate that there are significant changes in the properties of the binder after nine months of water conditioning. Further, dynamic modulus of the mixes prepared with the binder conditioned for nine months is significantly higher than the modulus of the unconditioned mix.
  Authors: Figueroa, Ana Sofia; Velasquez, Raul Andres; Reyes, Fredy; Bahia, Hussain U.
  Authors: Figueroa, Ana Sofia; Velasquez, Raul Andres; Reyes, Fredy; Bahia, Hussain U.
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 655
  Paper Number: 13-4280
• Asphalt Binder Contribution to Mixture Workability and Application of Asphalt Lubricity Test to Estimate Compactability Temperatures for Warm-Mix Asphalt
  Abstract: The disconnect between estimated compaction temperatures based on viscosity and behavior observed in laboratory and field compacted mixes indicates that sole use of viscosity is insufficient to characterize the role of the asphalt binder in mixture compaction. The Asphalt Lubricity Test was presented as a compliment or replacement to viscosity based on the concept that it is necessary to measure the properties of binders in thin films to better relate to compaction of mixes and to detect the effects of WMA additives. To assess the value of the Asphalt Lubricity Test, the relative contributions of lubricity, viscosity, and aggregate gradation on mixture workability at different levels of compactive effort were studied using statistical analysis. The mixes included fine and coarse gradations prepared with various conventional and WMA modified binders, compacted at a range of temperatures representative of those used for WMA. Results indicate that gradation and binder lubricity contribute significantly to mixture workability at conditions of lower temperature and/or lower density. The effects of viscosity were found insignificant. Aggregate gradation was found to be the most influential factor, indicating that for some mixes use of WMA additives is not always necessary to improve laboratory compaction. To support selection of compaction temperatures based on binder properties, a method to apply the Asphalt Lubricity Test to estimate minimum WMA compaction temperatures was presented.
  Authors: Hanz, Andrew; Bahia, Hussain U.
  Authors: Hanz, Andrew; Bahia, Hussain U.
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 704
  Paper Number: 13-4332
• Measuring Influence of Aggregate Coating on Workability and Moisture Susceptibility of Cold-Mix Asphalt
  Abstract: The purportedly higher moisture susceptibility of emulsified asphalt mixtures relative to traditional Hot Mix Asphalt (HMA) is a primary concern limiting their more widespread usage. Of the factors contributing to moisture susceptibility in Cold Mix Asphalt (CMA) that can be controlled by mix designers, aggregate coating is one of the most obvious physical means by which to reduce this distress. More complete aggregate coating is expected to help limit moisture susceptibility of CMA by reducing the amount of water that can be absorbed into exposed aggregate. This paper refines a recently developed method to quantify aggregate coating in CMA using digital imaging analysis and applies the procedure to several aggregate-emulsion systems to isolate factors most directly affecting aggregate coating. After identifying the most significant factors, a regression analysis of the coating matrix is used to develop quantitative models to predict coating of aggregates in CMA as a function of mix design parameters. Using models to predict several representative levels of aggregate coating, candidate mixtures were compacted in laboratory and workability and moisture susceptibility were assessed using a compactability parameter and modified Tensile Strength Ratio test, respectively. Results show that the workability and moisture susceptibility of CMA are highly dependent on the level of aggregate coating predicted by the quantitative models, suggesting that not only can the imaging procedure be used to reliably predict aggregate coating in CMA, but also could be used to develop practical, performance-based limits on plant-produced CMA mixtures in terms of aggregate coating.
  Authors: Ling, Cheng; Moraes, Raquel; Swiertz, Daniel; Bahia, Hussain U.
  Authors: Ling, Cheng; Moraes, Raquel; Swiertz, Daniel; Bahia, Hussain U.
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 655
  Paper Number: 13-4314
• Low-Temperature Performance Characterization of Biomodified Asphalt Mixtures Containing Reclaimed Asphalt Pavement
  Abstract: The sustainability movement in paving materials has led to the increased use of reclaimed asphalt pavement (RAP) in recent years. New developments in the area of pavement sustainability include the use of bio-modified asphalt binders (BMB) such as those containing bio-oils derived from swine manure. The current study examines the low temperature properties of RAP and virgin BMB mixtures to determine if these mixtures exhibit improved low temperature performance as compared to conventional hot mix asphalt (HMA).Disk-Shaped Compact Tension (DC(T)), Superpave Indirect Tension, and Acoustic Emission tests were employed to characterize low temperature properties of the asphalt mixtures. BMB mixtures exhibited higher DC(T) fracture energies as compared to HMA at all RAP levels. In addition, BMB mixture fracture energy displayed a reduced dependence on RAP content, as the difference in average fracture energy between BMB and HMA mixtures increased with higher RAP contents. Furthermore, BMB mixtures displayed consistently higher creep compliance which indicates that these mixtures can alleviate thermal stresses more easily than HMA.A recently developed acoustic emission testing procedure clearly indicated the effects of BMB as well as RAP in the mixture. The overall trends identified through AE testing were consistent with the findings from the DC(T) and ID(T) tests. In addition, AE results suggested a fundamental change in the behavior of the BMB RAP mixture relative to the HMA RAP mixture, e.g., a rejuvenating effect. In general, it was observed that BMB RAP mixtures exhibited superior low temperature cracking behavior as compared to HMA mixtures.
  Authors: Hill, Brian; Oldham, Daniel Joshua; Behnia, Behzad; Fini, Elham H.; Buttlar, William G.; Reis, Henrique
  Authors: Hill, Brian; Oldham, Daniel Joshua; Behnia, Behzad; Fini, Elham H.; Buttlar, William G.; Reis, Henrique
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 656
  Paper Number: 13-3773
• Laboratory Evaluation of Asphalt Mixtures Containing Bio-Binder Technologies
  Abstract: The use of bio-binder as a replacement to petroleum-based asphalt binders has received considerable attention in recent years. The objective of this study was to conduct a comprehensive laboratory evaluation of asphalt mixtures containing bio-binder technology at a content of 20, 25.5, 30, and 50%. To achieve this objective, Superpave Performance Grade (PG) of the modified blends was compared to the unmodified binder. In addition, a suite of laboratory tests was conducted to capture the mechanistic behavior of the mixtures against major distresses. Laboratory testing evaluated the rutting performance, moisture resistance, and fracture resistance of the produced mixtures using the Hamburg loaded-wheel tester, the modified Lottman test, the semi-circular bending (SCB) test, and the thermal stress restrained specimen (TSRST) test. Results of the experimental program showed that the use of bio-binder did not influence the final PG of the binder with the exception of one blend, which dropped one grade at low temperature. Mixtures modified with bio-binder had similar or improved rutting performance when compared to the conventional mixes. With respect to moisture susceptibility, all mixtures, except the mixes prepared with PG 67-22, exceeded the 80% tensile strength ratio. However, when an anti-stripping agent was added, the tensile strength ratio of the mix with 50% bio-binder exceeded 80%. With respect to fracture resistance at intermediate temperatures, the mixes containing bio-binder exhibited reduced fracture resistance as compared to conventional mixes. With respect to low temperature fracture performance, bio-binder modification improved the low temperature fracture performance of the mixtures when compared to conventional mixtures of similar performance grade.
  Authors: Mohammad, Louay N.; Elseifi, Mostafa A.; Cooper, Samuel; Challa, Harshavardhan; Naidoo, Prem
  Authors: Mohammad, Louay N.; Elseifi, Mostafa A.; Cooper, Samuel; Challa, Harshavardhan; Naidoo, Prem
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 597
  Paper Number: 13-3784
• Investigation of Rheological Behavior of Japanese Cedar-Based Biobinder as Partial Replacement for Bituminous Binder
  Abstract: There is about 90% of asphalt are used in the road and airport pavement construction. The majority of asphalt used nowadays is mainly derived from fossil fuel. However, due to the decreasing amount of petroleum reserves, the price of petroleum-based asphalt has increased that leads to the increasing the cost of hot-mix asphalt pavement construction. In addition, due to the improvement of oil refinery technology, the quality of asphalt binder also gradually degraded. Besides, from the environmental standpoint, it is also well recognized that the use of fossil fuel is the main source of producing greenhouse gases that will lead to the greenhouse effect. As the consequence, there is an urgent need to develop a more sustainable binding material from renewable resources or other alternatives resources to replace or modified the existing petroleum based asphalt binder for the highway industry.The main objective of this study is to investigate the potential use of bio-oil by-product as partially replacement of bituminous based binder. Therefore, the properties of several different blending combination of bio-binder and asphalt binder will be compared with unmodified asphalt binder through several physical, and rheological tests. Specific gravity of bio-binder is found to be higher than petroleum based binder. In general, bio-modified binders have higher viscosity than unmodified binder at high temperature above 60 °C. The 25% and 50% bio-modified binders have less temperature susceptibility. The addition up to 25% of bio-binder did not significantly change G* for the unaged case whereas RTFO-aged bio-modified binders show higher complex modulus and also more viscous than unmodified binder. Bio-modified binders show smaller Jnr value and better recovery ability than conventional AC-20.
  Authors: Yang, Shih-Hsien; Suciptan, Try; Chang, Ying-Hsi
  Authors: Yang, Shih-Hsien; Suciptan, Try; Chang, Ying-Hsi
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 596
  Paper Number: 13-3801
• Mean Profile Depth Analysis of Field and Laboratory Traffic-Loaded Chip Seal Surface Treatments
  Abstract: This paper presents a laboratory and field study to evaluate the mean profile depth (MPD) parameter that represents the surface texture of chip seal pavements. A three-dimensional laser profiler is used to determine the MPD values from both field pavement sections and field samples that have been tested in the laboratory using the third-scale model mobile loading simulator (MMLS3). Data obtained from five different field-constructed chip seal sections are used to evaluate the effects of different factors on the MPD of chip seal pavements. These factors include aggregate type, emulsion application rate, field versus MMLS3 traffic loading, and traffic volume. The results presented in this paper suggest that: (1) chip seal pavements constructed using lightweight aggregate have larger initial MPD values and faster reduction in MPD as a function of the number of wheel passes than those constructed using granite 78M aggregate; (2) MPD values obtained from a drier section (with drier indicating a lower emulsion-to-aggregate ratio than that of the sections it is being compared against) initially drop quickly and significantly, resulting in a much smaller ultimate MPD value; (3) in general, the MPD values obtained under MMLS3 loading are similar to those obtained from field traffic loading, thus allowing the translation of the laboratory MMLS3 data to the field response data; (4) a short rest period in a high traffic volume road retards the recovery of the binder and therefore leads to more permanent changes in the MPD; and (5) the initial measured MPD value can help predict aggregate loss performance.Keywords: mean profile depth, asphalt surface treatments, chip seal, traffic load
  Authors: Kim, Y. Richard; Adams, Javon Marcell
  Authors: Kim, Y. Richard; Adams, Javon Marcell
  Year: 2013
  Document Type: Paper
  Subject: Maintenance and Preservation; Materials; Pavements
  Session: 654
  Paper Number: 13-3884
• Enhancement of Permanent Deformation Model for Unbound Materials Used by DARwin-ME
  Abstract: This study deals with the assessment and enhancement of the Mechanistic-Empirical Pavement Design Guide (MEPDG) permanent deformation model for unbound materials. A preliminary sensitivity study of the current model was conducted which yielded some limitations when typical soil properties were used for a variety of AASHTO Classification groups. Based on the results from the sensitivity analysis, an enhanced mechanistic model was developed and is the main goal of this paper. The proposed model was developed based on a database consisting of a total of nearly 4,000 laboratory data points obtained from experiments previously conducted at Arizona State University. The database contains results of static triaxial shear strength and repeated load triaxial tests conducted on four subgrade materials from the State of Arizona. The materials included gravelly and sandy materials with a wide range of fines content (1% to 32%). The proposed model predicts the permanent to resilient strain ratio (åp/år) and was found to be a function of the degree of saturation, shear stress/strength ratio, number of stress repetitions, plasticity index of the soil and percentage passing US Standard No. 200 sieve. The model was found to be rational, unbiased, and statistically sound. Interestingly, the shear stress/strength ratio proved to be a better predictor than the resilient modulus, provided degree of saturation and properties of the fine material were considered.
  Authors: Zapata, Claudia E.; Bani Hashem, Elham
  Authors: Zapata, Claudia E.; Bani Hashem, Elham
  Year: 2013
  Document Type: Paper
  Subject: Geotechnology; Materials; Pavements
  Session: 293
  Paper Number: 13-3934
• Simplified Approach for Evaluating Interlayer Shear Resistance in Asphalt Pavement
  Abstract: The lack of interlayer shear resistance might result in slippage between pavement layers and cause U-cracking in surface. An approach to evaluate the shear resistance in asphalt pavement based on shear strength envelope for asphalt pavement interface was developed. The distributions for shear stress and normal stress in pavement interface under traffic load were analyzed by finite element method. According to the results of scatter plot of shear stress and normal stress, the formation of shear stress critical boundary was identified. The criterion which would guarantee the performance of shear resistance for tack coat materials is that there is no intersection of shear stress critical boundary and shear strength envelope. By introducing the shear fatigue equation at interface, fatigue life is connected to the parameters of shear strength envelope, cohesion (c) and internal friction angle (f). Discussions about effects of cohesion (c) and internal friction angle (f) on shear fatigue life are also conducted. Further research for incorporating shear fatigue factors into this evaluation is also discussed.
  Authors: Jia, Xiaoyang; Huang, Baoshan; Li, Lihan
  Authors: Jia, Xiaoyang; Huang, Baoshan; Li, Lihan
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 655
  Paper Number: 13-3943
• Critical Problems with Using Asphalt Ductility Test as Performance Index for Modified Binders
  Abstract: Despite the adaptation of advanced binder rheology characterization methods by many agencies, the asphalt ductility test is still under use in some specifications in the USA and a few countries as a performance indicator for asphalt modification. In the present study a set of binders modified with two types of commonly used elastomeric polymer modifiers were characterized in terms of fundamental, well-defined, binder properties known to reflect rutting and fatigue resistance, results of which showed no correlations with binder ductility.Additionally, a test procedure was developed using a Dynamic Shear Rheometer (DSR) as a surrogate to the conventional ductility test, results of which showed that both elastomeric modified binders are much more ductile than conventional binders, even when conventional ductility showed a loss of ductility. Finite Element Modeling (FEM) was used to show the significant effects of decreasing true strain rates with elongation on the sample’s stress and strain state due to the constant cross head speed in the conventional ductility test. Due to the well-known dependency of failure stress and strain of viscoelastic material on strain-rate and temperature, comparing binders with varying ductility values measured in the conventional test is essentially flawed as it is equivalent to comparing them at different temperatures, thus fundamentally unreliable as an indicator of the asphalt’s performance in the pavement. It is therefore strongly recommended that the practice of using low temperature conventional ductility be removed from modified binder specifications, or the DSR procedure proposed in this paper be used to evaluate modified asphalts.
  Authors: Tabatabaee, Hassan A.; Clopotel, Cristian; Arshadi, Amir; Bahia, Hussain U.
  Authors: Tabatabaee, Hassan A.; Clopotel, Cristian; Arshadi, Amir; Bahia, Hussain U.
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 604
  Paper Number: 13-4125
• Mechanism of Crumb Rubber Modifier Dissolution into Asphalt Matrix and Its Effect on Final Physical Properties of Crumb Rubber Modifier Binder
  Abstract: Modification of asphalt by Crumb Rubber Modifier (CRM) is mostly done through exchange of components between asphalt and CRM. At low interaction conditions CRM absorbs aromatics of asphalt and swells; however, at higher interaction conditions, the 3D structure of CRM starts degrading which leads to the release of different components of CRM into the asphalt matrix. The released components include carbon black and fillers, polymeric chains and also oily components of CRM. Under different interaction conditions this mechanism is performed differently and therefore the state and role of the released components can be different. In this research the state of the released components in the asphalt matrix and their effect on property development of modified asphalt was studied using different analytical techniques including, Dynamic Shear Rheometer (DSR), Thermo-Gravimetric Analysis (TGA), and Fourier Transform Infrared spectroscopy (FTIR). TGA and FTIR show the type and amount of released components from CRM into the asphalt matrix. The results reveal that interaction temperature is the main factor affecting the mechanism of the release of components from CRM. DSR results indicate that under an intermediate interaction temperature (i.e.190¢ªC) and a high mixing rate (i.e.50Hz), released components are more effective on physical properties of asphalt than the released components under a very high interaction temperature (i.e.220¢ªC). The difference in the released components for the moderate and high interaction temperatures is attributed to the mechanism of dissolution and the state of released components.
  Authors: Ghavibazoo, Amir; Abdelrahman, Magdy; Ragab, Mohyeldin Safwat
  Authors: Ghavibazoo, Amir; Abdelrahman, Magdy; Ragab, Mohyeldin Safwat
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 596
  Paper Number: 13-4259
• 4.75-mm SMA on Thin Durable Asphalt Overlays
  Abstract: This paper presents the development of stone matrix asphalt (SMA) with 4.75-mm nominal maximum aggregate size (NMAS) and alternative surfacing cross-section for an asphalt wearing course that may improve pavement performances while controlling costs by using locally available aggregates. The 4.75-mm NMAS dense-graded mix was previously used in a few states in order to reduce layer thickness and for its cost-effective application. However, due to its poor friction and limited performance, it was generally used as leveling binder and placed on low-volume roads. To improve surface texture and its performance, the 4.75-mm SMA is proposed for thinner asphalt overlays in this study. The ultimate goal of this study is to develop the 4.75-mm SMA and evaluate its performance as a wearing course under laboratory and field conditions. Test pavement sections were constructed in October and November 2010 in northern Illinois to evaluate its performance under actual traffic loading. On-site performance tests were conducted, and the results suggest its proper application as an efficient and cost effective wearing course that improves pavement performance.
  Authors: Son, Songsu; Al-Qadi, Imad L.; Zehr, Thomas G.
  Authors: Son, Songsu; Al-Qadi, Imad L.; Zehr, Thomas G.
  Year: 2013
  Document Type: Paper
  Subject: Materials; Pavements
  Session: 517
  Paper Number: 13-4378
• Nonlinear Viscoelastic Behavior of Asphalt Concrete and Its Implication on Fatigue Modeling
  Abstract: Mechanistic models for asphalt concrete (AC) can consider many different physical mechanisms. However, as more mechanisms are considered, the complexity increases, and it becomes important to balance accuracy and complexity to create a model that can be used by the engineering community. In some cases, the material response is dominated by the effects of only some key processes and smearing the effects of the minor ones is acceptable. In other cases, many different processes are important and need to be considered. In this paper, the importance of modeling the nonlinear viscoelasticity (NLVE) of AC for fatigue response prediction is assessed. Two mechanistic hypotheses are considered for describing this phenomenon; 1) linear viscoelastic with damage and 2) NLVE with damage. The importance of explicitly considering NLVE effects under fatigue loading is evaluated by using laboratory tests, the simplified viscoelastic continuum damage (S-VECD) model, and a NLVE form of the S-VECD model. These two models are characterized and used to simulate and compare AC fatigue response under constant and random controlled stress and strain conditions. It is found that while the NLVE based formulation better represents the material response in random loading and suggests less overall damage accumulation during fatigue, that the two models predict very similar amounts of modulus reduction. The primary conclusion from this study is that since the goal for fatigue assessment is to find the change in modulus over a long period of time, fatigue response modeling of AC does not need to explicitly consider NLVE.
  Authors: Underwood, Shane; Kim, Y. Richard
  Authors: Underwood, Shane; Kim, Y. Richard
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 840
  Paper Number: 13-4380
• Effects of Emulsion Type on Bending-Beam Rheometer Field-Aged Asphalt Concrete Beams
  Abstract: One of the functions of asphalt emulsions is to rejuvenate the surface of an aged asphalt concrete roadway. However, it is unclear as to the effectiveness of different types of asphalt emulsions, as most current testing is empirical in nature and does not give an indication of the performance of the asphalt emulsion. Using asphalt concrete beams from the surface of a roadway in the Bending Beam Rheometer, however, can give an indication of an asphalt emulsion’s ability to decrease the stiffness and affect the creep rate or change in stiffness (m-value) of the roadway samples. Seven emulsions at three application rates on two roadways were examined to identify the effect of emulsion on the stiffness and m-value of asphalt concrete. There was no easily identified difference between the three application rates for either field section or any of the emulsions. However, the m-value tended to increase with the addition of emulsion and the stiffness tended to decrease. This indicates that the BBR can be used to determine the effect of asphalt emulsion on the creep change and the stiffness of field samples in the Bending Beam Rheometer.
  Authors: Braham, Andrew; Howard, Isaac L.; Barham, Jason
  Authors: Braham, Andrew; Howard, Isaac L.; Barham, Jason
  Year: 2013
  Document Type: Paper
  Subject: Maintenance and Preservation; Materials; Pavements
  Session: 654
  Paper Number: 13-4384
• Enhancing Performance of Crumb Rubber-Modified Asphalts Through Controlling Internal Network Structure
  Abstract: In the current research, the effect of controlling the internal network structure of Crumb Rubber Modified Asphalts (CRMA) on property development was investigated. The investigation included evaluation by rheological and interrupted shear tests. Rheological testing involved monitoring the changes of the produced complex modulus (G*) and phase angle (ä) for the CRMA. In the interrupted shear tests, the shear stress profile for the produced CRMA was investigated. It was found that triggering critical conditions of combined interaction speed, temperature and time is essential to induce the formation of 3D network structure within the CRMA. Such triggering conditions play an important role in swelling, dissolution and release of Crumb Rubber Modifier (CRM) components into the asphalt liquid phase. Gel Permeation Chromatography (GPC) was utilized to characterize the nature of modifications that lead to the occurrence of 3D network structure within the produced CRMA. Formation of 3D network structure for the CRMA plays a major role in the enhancement of its rheological properties in terms of its stiffness and elasticity. Superior improvements in the stiffness and elasticity indicate improved rutting resistance as well as alleviated permanent deformation problems.
  Authors: Ragab, Mohyeldin Safwat; Abdelrahman, Magdy; Ghavibazoo, Amir
  Authors: Ragab, Mohyeldin Safwat; Abdelrahman, Magdy; Ghavibazoo, Amir
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 656
  Paper Number: 13-4363
• Improving Concrete Sustainability and Performance UsingPortland-Limestone Cement Synergies
  Abstract: Increased use of portland-limestone cements (PLC’s) in the US is anticipated, as a new provision for PLC’s containing up to 15% limestone has been added to blended cement specifications. Published research has documented performance synergies of cementitious mixtures with finely ground limestone (particle sizes generally smaller than for cement), especially in combination with certain sup¬plementary cementitious materials (SCM’s). Time of setting and strength development bene¬fits are reported, generally in proportion to limestone fineness. It appears possible to fully develop poten¬tial for these performance synergies in mill-ground PLC’s, in which lime¬stone comprises the majority of the finest particles. In this paper, performance trends observed in concrete with PLC have been further investigated using separately propor¬tioned ground limestone and ordi¬nary portland cement (OPC) as well as mill-ground PLC samples. Influ¬ences of variables such as SCM type and lime¬stone fineness were evalu¬ated using laboratory paste mixtures. Set acceleration increased with limestone fineness for all combinations in¬cluding mix¬tures without SCM’s. Strength synergies were clearly evi¬dent with all SCM’s, more signifi-cantly with Class C ash and slag cement than with Class F ash. All strength trends improved as lime¬stone fineness was increased. Consistent synergies that enhance setting and strength performance appear achieva¬ble with PLC’s. Optimizing particle fineness will be a key factor in achieving these benefits. Performance contributions of SCM’s in combinations with PLC’s may exceed those of similar mixtures with traditional OPC’s, thus SCM use can be maximized and related sustainability impacts further extended.
  Authors: Cost, Tim; Howard, Isaac L.; Shannon, Jay
  Authors: Cost, Tim; Howard, Isaac L.; Shannon, Jay
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 288
  Paper Number: 13-4429
• Effect of Supplementary Cementitious Materials on Creep and Shrinkage Behavior of Self-consolidating Concrete
  Abstract: Self Consolidating Concrete (SCC) is concrete material that is finding its to structural applications such as prestressed concrete girders, columns, etc., due to its excellent surface finish and less reliance on labor for the proper consolidation. However, the creep and shrinkage properties of SCC containing supplementary cementitious material, such as silica fume (SF), Fly Ash (FA) or slag (SL), are based on limited research. There is a need for comprehensive testing and evaluation of SCC mixes in order to be able to determine their properties for use in structural design applications.This paper presents results of study to evaluate the effect of the supplementary cementitious materials and different cement contents on the creep and shrinkage behaviors of self-consolidating concrete (SCC). Four different groups of SCC mixes were evaluated. The first group consists of three SCC mixes containing 3, 5 and 10% SF. The second group consists of three SCC mixes containing 10, 20 and 30% FA. The third group consists of SCC mixes containing 10, 20 and 30% SL and the last group consists of SCC mixes containing 800, 850 and 900 lbs of cement. Results show that high volumes of SF and SL as well as low amount of cement content reduced the creep while high volume of FA reduced the shrinkage of SCC. On the other hand, it was observed that a high volume of SF increases the shrinkage of SCC. In addition, the experimental creep and shrinkage results were compared to the predicted results obtained from the ACI 209 and CEB code models as well as B3 and GL2000 analytical models. According to the results, B3 and GL2000 analytical models were the best models to fit the experimental creep and shrinkage results for SCC.
  Authors: Nassif, Hani; El-Khoury, Raymond
  Authors: Nassif, Hani; El-Khoury, Raymond
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 286
  Paper Number: 13-4438
• A Comparative Study on Compressive Strength of Recycled Plastic Pin, Wood Lumber and Bamboo at Different Environmental Conditions
  Abstract: The use of Recycled Plastic Pin (RPP) to stabilize shallow slope failure offers a great economic and construction benefit and has marked a notable recognition in the engineering community. RPP driven into the soil slope face may go beyond possible slip surface that provides an additional resistance force along the slip plane and increase the factor of safety. Natural structural element, wood lumber and bamboo are available in abundance in developing countries and can be utilized for slope stabilization. The objective of the current study is to compare the compressive strength of RPP, wood lumber and bamboo under different environmental conditions. Based on the ASTM standards and field conditions, three different strain rates were applied during the study. Moreover, different environmental exposures were considered, 1) Acidic condition 2) Alkaline condition and 3) Neutral condition that represent different clayey soils in Texas. The test results indicated that wood and bamboo possesses higher peak strength at the normal condition compared to RPP. However, the strength of wood and bamboo were decreased by 65% and 71% respectively under different environmental conditions, in contrast strength reduction for RPPs was insignificant. Therefore, for the pinning of the slope in United States, the wood and bamboo could be a better solution compared to the RPP for short term stabilization. However, for long term stabilization, RPP could perform better due to its environmental resistant behavior. Bamboo is available in most of the developing countries and could be utilized for the slope stabilization in both short term and long term conditions.
  Authors: Khan, Mohammad Sadik; Hossain, Md. Sahadat; Ahmed, Faisal Shakib
  Authors: Khan, Mohammad Sadik; Hossain, Md. Sahadat; Ahmed, Faisal Shakib
  Year: 2013
  Document Type: Paper
  Subject: Geotechnology; Materials
  Session: 746
  Paper Number: 13-4446
• Endurance Limit for Hot-Mix Asphalt Based on Healing-Damage Balance Criterion Using Viscoelastic Continuum Damage Analysis
  Abstract: Fatigue endurance limit (FEL) is a key parameter for designing perpetual pavements to mitigate bottom-up fatigue cracking. This study was conducted as part of the National Cooperative Highway Research Program (NCHRP) Project 9-44A to develop a framework and mathematical methodology to determine the FEL using the uniaxial fatigue test. In this unique procedure, the FEL is defined as the allowable tensile strains at which a balance takes place between the fatigue damage during loading, and the healing during the rest periods between loading pulses. The viscoelastic continuum damage model was used to isolate time dependent damage and healing in hot mix asphalt from that due to fatigue. The laboratory testing program consisted of dynamic modulus testing to estimate the viscoelastic properties of the asphalt mixtures, and uniaxial fatigue test experiment conducted with and without rest periods. Five factors that affect the fatigue and healing behavior of asphalt mixtures were evaluated: asphalt content, air voids, temperature, rest period and tensile strain. Based on the test results, a Pseudo Stiffness Ratio (PSR) regression model was developed that is a function of the five factors and the number of loading cycles. The FEL was defined when PSR is equal to 1.0 (net damage is equal to zero). The determined FEL values were rational compared to historical literature ranges. The results from the sensitivity analysis showed rational relationships between the FEL and investigated factors.
  Authors: Zeiada, Waleed Abdelaziz; Souliman, Mena I.; Kaloush, Kamil E.; Mamlouk, Michael S.
  Authors: Zeiada, Waleed Abdelaziz; Souliman, Mena I.; Kaloush, Kamil E.; Mamlouk, Michael S.
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 599
  Paper Number: 13-4507
• Evaluation of Low-Temperature Properties of Asphalt Binders and Mixtures
  Abstract: With the widespread use of modifiers and additives in asphalt bitumen, this study revisits and evaluates the adaptation of the time-temperature superposition principle that is incorporated in the low temperature Superpave™ binder specifications. The study builds on results of Bending Beam Rheometer (BBR) tests conducted on samples of asphalt binders used in seven different surface layer mixtures. Both 240-second and 2-hour BBR tests were conducted at three different temperatures: the low temperature of the asphalt PG grade (TL), 10°C higher than the low temperature grade (TL+10), and at -5°C to construct the flexural creep stiffness, S(t), master curves. Additionally, indirect tensile tests (IDT) were conducted on the surface layer mixtures to determine the low temperature properties. The BBR test results show that the methodology adopted in utilizing the equivalence principle to formulate the low temperature Superpave™ binder specifications does not accurately apply for some of the binders used in this study. Thus, modifications to the specifications with regard to loading times and test temperatures are suggested. Further, the time-temperature shift factors for the binders evaluated are compared with the universal shift factors used in the Strategic Highway Research Program (SHRP) study. The observed mismatch in the shift factor sets is in disagreement with the implicit assumption that all asphalt binders can be characterized by similar shift factors at low temperatures. The shift factors of the binders and mixtures used in this study tend to match well particularly at high testing temperatures.
  Authors: Premkumar, Laxmikanth; Chehab, Ghassan R.; Solaimanian, Mansour
  Authors: Premkumar, Laxmikanth; Chehab, Ghassan R.; Solaimanian, Mansour
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 374
  Paper Number: 13-4529
• Use of Moisture-Induced Stress Testing to Evaluate Stripping Potential of Hot-Mix Asphalt
  Abstract: Stripping of hot mix asphalt (HMA) in the field is an ongoing issue for many Departments of Transportation (DOTs). A leading cause of stripping is hydraulic scouring. The Moisture Induced Stress Tester (MIST) is a recently developed technology that applies alternating pressure and vacuum cycles to submerged asphalt samples to mimic hydraulic scouring. The objective of this study was to differentiate six HMA mixes used by Maine DOT in terms of their moisture susceptibility using the latest MIST technology and field cores. Half of the field cores were conditioned in the MIST. Before and after conditioning visual observations were made, and the bulk specific gravity and resilient modulus were determined using the CoreLok and ASTM D4123, respectively. All conditioned and unconditioned samples were tested for indirect tensile strength (ITS) in accordance with ASTM D 6931. Values from before and after conditioning were compared by HMA mix. It was determined that the MIST conditioning process does cause moisture damage to the samples in a manner that mimics hydraulic scouring. It is recommended that further research be carried out to investigate the effect of the MIST on HMA cores, and that parameters be developed for characterizing the results of the MIST conditioning process. These results would also help in the development of standard specifications for the use of MIST
  Authors: Pinkham, Rudy; Cote, Sarah Ann; Mallick, Rajib B.; Tao, Mingjiang; Bradbury, Richard L.; Regimand, Ali
  Authors: Pinkham, Rudy; Cote, Sarah Ann; Mallick, Rajib B.; Tao, Mingjiang; Bradbury, Richard L.; Regimand, Ali
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 467
  Paper Number: 13-4538
• Development of a Simple Test to Determine Workability and Field Compaction Temperatures of Asphalt Concrete
  Abstract: A simple and easy-to-use test method to determine workability of asphalt mixtures was developed. This new method, called ‘Dongre Workability Test’ (DWT – pronounced DWIGHT), uses the Superpave Gyratory Compactor (SGC) to measure workability. DWT is conducted under displacement control at the rate of 0.05 mm/s in the gyratory compactor using 4224 g of asphalt loose mix. No gyrations are used in the DWT. Workability of asphalt concrete, expressed in kPa units, is defined as the slope of the non-linear stress (kPa) versus volumetric strain (%) curve calculated at 600 kPa stress level. DWT is able to resolve differences in workability due to aggregate gradation, asphalt binder grade, warm mix additives and polymer modification.A chart was also developed as a part of this study to establish field compaction temperatures using the workability values (on-mat and off-mat rolling temperatures for field compaction). Using this chart and the DWT workability values at two test temperatures (200oF and 300oF), field compaction temperatures were successfully predicted for various warm-mix, hot-mix and polymer modified asphalt mixtures. DWT may also be used to calculate the temperature reduction by the use of warm-mix additives.
  Authors: Dongre, Raj N.; Morari, Eugene
  Authors: Dongre, Raj N.; Morari, Eugene
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 597
  Paper Number: 13-4542
• Approach for Quantifying Effect of Binder Oxidative Aging on Viscoelastic Properties of Asphalt Mixtures
  Abstract: Due to the noted influence of oxidative aging on the mixture properties and pavement performance, it is becoming imperative to have a more complete understanding of the influence of asphalt binder aging on the viscoelastic behavior of asphalt mixtures. This study proposes a new approach to correlate the oxidative aging of asphalt binder in terms of carbonyl functional groups to the viscoelastic behavior of asphalt mixtures in terms of a continuous relaxation spectrum. The asphalt mixture complex modulus, E*, and the carbonyl area, CA, for the recovered asphalt binder were measured for mixtures subjected to varying durations of long-term aging in the laboratory. The continuous relaxation spectrum was obtained analytically from the 2S2P1D model of complex modulus of asphalt mixture through the inverse Fourier-Laplace transform approach. A consistent horizontal shift in the continuous relaxation spectrum was observed for all mixtures with the increase in aging duration. However, the shape and the amount of shifting of the spectra were mixture dependent. In particular, mixtures with higher asphalt binder absorption exhibited the largest shift in the continuous spectra for both unmodified and polymer-modified asphalt mixtures. Good correlations were observed between the carbonyl in asphalt binder and the continuous relaxation spectrum parameters of the asphalt mixture. Such relationships should permit the incorporation of long-term oxidative aging directly into the constitutive equation utilized in pavement response analyses.
  Authors: Alavi, Mohammad Zia; Hajj, Elie Y; Morian, Nathan
  Authors: Alavi, Mohammad Zia; Hajj, Elie Y; Morian, Nathan
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 599
  Paper Number: 13-4560
• Replacing Thermal Sprayed Zinc Anodes on Cathodically Protected Steel Reinforced Concrete Bridges: Experimental and Modeling Studies
  Abstract: This research aimed to address questions underlying the replacement of arc-sprayed zinc anodes on cathodically protected steel reinforced concrete bridges and to develop a protocol to prepare the concrete surface for the new anode through a combination of laboratory test and modeling studies. To achieve strong initial bond strength of new zinc to the existing bridge concrete, the current operating configuration (#8 nozzle with high sand volume) is too aggressive and should be changed to #6 nozzle with low sand volume to achieve target RMS macro-roughness of 1.2-2.1 centi-inches and micro-roughness of 0.014-0.02 centi-inches. It is recommended to adjust the anode removal and surface profiling based on the electrochemical age of the existing concrete. Wherever possible, large aggregates (e.g., diameters ¾ in. and bigger) should be avoided for exposure by surface profiling. For non-electrochemically aged concrete, profile the surface to achieve a RMS macro-roughness of 1.1-1.8 centi-inches and 5-36% exposed aggregates. For existing concrete with relatively high electrochemical age (14 yrs), profile the surface to achieve a RMS macro-roughness of 1.1-1.5 centi-inches and 44-55% exposed aggregates.
  Authors: Shi, Xianming; Li, Yongxin; Cross, Doug; Ewan, Levi; Fortune, Keith; Soltesz, Steven M.; Jungwirth, Scott
  Authors: Shi, Xianming; Li, Yongxin; Cross, Doug; Ewan, Levi; Fortune, Keith; Soltesz, Steven M.; Jungwirth, Scott
  Year: 2013
  Document Type: Paper
  Subject: Bridges and Other Structures; Maintenance and Preservation; Materials
  Session: 401
  Paper Number: 13-4543
• Interface Layer Tack Coat Optimization
  Abstract: Interface bonding is a key factor affecting the pavement performance life. This paper focuses on optimizing in-situ tack coat application rate and field installation. The objective was to validate the lab-determined optimum residual application rate and evaluate field performance of tack coat materials. The parameters analyzed include: cleaning method, paving procedure, tack coat type, and existing pavement surface. Tack coat materials used were SS-1h, SS-1hp, and SS-1vh (non-track tack coat). Two cleaning methods were used: broom and vacuum, and air-blast. Two paving procedures were studied: conventional paving using a distributor and a regular paver, and spray-paver. Two projects were selected: Interstate 80 and Illinois Route 98. Cores were tested using the Interface Shear Test Device (ISTD). Results showed similar bond strength for both cleaning methods; however, air-blast cleaning reduced the required optimum residual application rate. The resulting interface bond strength is similar when using either of the paving procedures considered. SS-1vh performed better than any other material studied. Identification of the optimum tack coat application rate will help ensure cost-effective and efficient tack coat application in the field.
  Authors: Salinas, Alejandro; Al-Qadi, Imad L.; Hasiba, Khaled; Ozer, Hasan; Leng, Zhen; Parish, Derek
  Authors: Salinas, Alejandro; Al-Qadi, Imad L.; Hasiba, Khaled; Ozer, Hasan; Leng, Zhen; Parish, Derek
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 655
  Paper Number: 13-4576
• Tack Coat Optimization: Testing Device Development and Laboratory Testing
  Abstract: The main objective of this study was to evaluate the performance of various tack coats and determine the optimum residual application rates for three pavement surfaces: unmilled aged nontrafficked, milled aged, and unmilled aged trafficked asphalt concrete (AC). The study also examined the influences of tack coat curing time, temperature, asphalt mixture type, and surface texture on the performance of tack coats. The study considered four tack coat materials: SS-1hp, high float emulsion (HFE), SS-1vh (very hard, non-track emulsion), and binder grade (PG 64-22). The tack coat was optimized at residual rates of 0.00 to 0.36 L/m2 (0.00 to 0.08 gal/yd2). Three curing times were considered: 0.25, 2, and 24 hrs. Two overlay mixes (9.5-mm surface mix and 4.75-mm surface mix) were used. Prior to testing, the specimens were conditioned at four temperatures: -15°C, 5°C, 25°C, and 45°C (5°F, 41°F, 77°F, and 113°F). The study found that the optimum tack coat residual rate was 0.18 L/m2 (0.04 gal/yd2) for trafficked and nontrafficked unmilled aged AC surfaces, while the optimum residual rate for milled AC was 0.26 L/m2 (0.06 gal/yd2). SS-1vh tack coat showed superior performance over the other tested tack coats. The optimum curing time was determined to be 2 hrs. Milling the surface improved interface shear strength. The interface shear resistance was greater when the surface nominal maximum aggregate size (NMAS) increased from 4.75 mm to 9.5 mm. Increasing the temperature resulted in a reduction in shear strength. However, the shear strength also reduced when the temperature becomes below the glassy temperature. ¬Result analysis showed that SS-1vh has the greatest stiffness amongst the tested tack coats. This increases with temperature reduction in spite of loss in interface shear strength.
  Authors: Hasiba, Khaled; Al-Qadi, Imad L.; Salinas, Alejandro; Ozer, Hasan; Leng, Zhen; Parish, Derek
  Authors: Hasiba, Khaled; Al-Qadi, Imad L.; Salinas, Alejandro; Ozer, Hasan; Leng, Zhen; Parish, Derek
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 655
  Paper Number: 13-4597
• Mechanistic-Based Approach to Evaluate Rutting Susceptibility of Hot-Mix Asphalt Mixtures Using Dynamic Triaxial Testing
  Abstract: The performance of an asphalt pavement is significantly impacted by the properties of the asphalt mixture, pavement structure, and the imposed environmental and traffic loading conditions. In particular, hot mix asphalt (HMA) mixtures are believed to have a critical combination of temperature and traffic loading rate which will result in excessive permanent deformation. This study presents a new approach to assess the rutting susceptibility of HMA mixtures under a given set of traffic loads and environmental conditions. The approach consists of evaluating asphalt mixtures using the repeated load triaxial (RLT) test at field representative testing conditions to determine the critical temperature of the HMA beyond which the mix becomes unstable. An HMA was considered appropriate for a specific project location if the determined critical temperature was greater than the effective asphalt pavement temperature for rutting determined using the Mechanistic-Empirical Pavement Design Guide (MEPDG) software. Predictive equations that account for the actual project characteristics such as climate conditions, material characteristics, operational speed, and traffic loading were developed in this study to estimate the effective asphalt pavement temperature. Nine HMA mixtures, each of which were associated with a specific project that has performed well in rutting, were characterized and analyzed for rutting behavior. The critical temperature for each HMA was obtained using RLT results and actual field performance. Flow number criteria as a function of traffic level were also developed for the HMA mixtures. The proposed approach was validated using three additional mixtures from Nevada and two mixtures from the WesTrack accelerated test facility. Good agreement between laboratory results and field performance was achieved.
  Authors: Ulloa Calderon, Alvaro Esteban; Hajj, Elie Y; Sebaaly, Peter E.
  Authors: Ulloa Calderon, Alvaro Esteban; Hajj, Elie Y; Sebaaly, Peter E.
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 599
  Paper Number: 13-4599
• Comparison Between Mechanistic Properties of Laboratory and Field-Produced Warm-Mix Asphalt Mixtures from Manitoba, Canada
  Abstract: The purpose of this study was to compare laboratory performance of field and laboratory-produced mixtures from Manitoba, Canada in terms of their resistance to moisture damage, permanent deformation and reflective cracking. The project was constructed in summer of 2010 and consisted of a single HMA control section and three WMA sections in which Advera, Evotherm 3G, and Sasobit technologies were used. The mixture’s susceptibility to moisture damage was evaluated using the unconditioned and moisture-conditioned indirect tensile strengths (ITS) and dynamic modulus (|E*|) at multiple freeze-thaw (F-T) cycles. The repeated load triaxial (RLT) test was used to evaluate the permanent deformation, while the Texas Transportation Institute Overlay Tester was used to characterize the reflective cracking behavior. In general, the properties of the field-produced mixtures were different than those of the laboratory-produced mixtures with the difference being mix dependent. The use of multiple freeze-thaw cycling resulted in a larger difference between the indirect tensile strength and the dynamic modulus of the field and laboratory-produced mixtures. This difference between the two mixtures, is primarily attributed to the current procedures and practices used in the laboratory to prepare and condition (i.e. age) asphalt mixtures, in particular WMA mixes. The field observations of the constructed pavements showed no rutting or moisture damage, but reflective cracking was seen in all of the road sections. The extent of the cracking followed the relationships seen in the laboratory testing, except for the Sasobit sections.
  Authors: Porras-Alvarado, Juan Diego; Hajj, Elie Y; Sebaaly, Peter E.; Harnsberger, P. Michael; Kass, Said; Liske, Tara
  Authors: Porras-Alvarado, Juan Diego; Hajj, Elie Y; Sebaaly, Peter E.; Harnsberger, P. Michael; Kass, Said; Liske, Tara
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 704
  Paper Number: 13-4603
• Modeling the Resilient Modulus for RAP Applications in Base Course Layers
  Abstract: The resilient modulus (MR) is an important parameter for base course layer. Utilizing RAP for 2 this layer must take into consideration the effect of various factors that may occur in the field on 3 the resilient modulus. Previous numerical models used for granular base layer could be utilized 4 for the RAP. Therefore, this research studies the suitability of using RAP procedures under the 5 effect of different factors such as water content, dry density, freezing-thawing cycles. Various 6 percentages of RAP (50%, 75% and 100% by weight) are employed in this research. All the 7 models included in the study take directly the effect of state of stresses but they consider the 8 other mentioned factors and their interactions on the resilient modulus indirectly. Results of this 9 study will determine the adequacy of the employed models in using RAP procedure in the base 10 course layer and which model best fits for RAP behavior under the effect of tested factors. Based 11 on the literature review, nine prediction models were chosen in this study to deal with the 12 granular base course layers so as to predict MR for RAP. A pilot analysis was made on these 13 models to compare between the measured and predicted values on MR under the tested factors. 14 Three models showed a good prediction for MR. These three models were assessed again in a 15 sensitivity analysis on regression parameters to choose the best-fit model for the RAP 16 applications.
  Authors: Noureldin, Ehab Magdy; Abdelrahman, Magdy
  Authors: Noureldin, Ehab Magdy; Abdelrahman, Magdy
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 656
  Paper Number: 13-4627
• Monitoring and Assessment of Concrete Deck Cracking Potential in Negative Moment Regions
  Abstract: Replacement of concrete decks is usually achieved using staged construction techniques to avoid causing disruption to the traveling public. Trucks traveling in traffic lanes adjacent to fresh concrete pours increase the cracking potential of concrete decks as was observed upon completion of the first stage of construction of a highly skewed continuous span bridge located on the New Jersey Turnpike. The majority of the observed cracks occurred right after construction and was centered in the negative moment region. Many questions were raised to understand the type and causes of these cracks. The purpose of this study was to investigate the behavior of the bridge using non-destructive testing and evaluation methods. Strain gauges were embedded in the concrete slab during the pour of the southbound half of the bridge. Material samples were collected to measure the mechanical properties of the concrete slab. A finite element model of the bridge was developed to simulate its overall behavior. The model was validated using a static load test performed on the structure. Thereafter, live load analyses were performed using the 3-D model. It was found that the strength of the concrete mix used was inadequate to support the imposed live load stresses at an early age in addition to shrinkage and temperature strains. Based on FE analysis and simulation, a solution was proposed to modify the High Performance Concrete (HPC) mix to a High Early Strength (HES)-HPC mix that exhibited a reduction in cracking potential of the bridge deck compared to an HPC mix.
  Authors: Nassif, Hani; Adediji, Ope; Su, Dan; Lou, Peng; Johnsen, W. Scott
  Authors: Nassif, Hani; Adediji, Ope; Su, Dan; Lou, Peng; Johnsen, W. Scott
  Year: 2013
  Document Type: Paper
  Subject: Bridges and Other Structures; Maintenance and Preservation; Materials
  Session: 401
  Paper Number: 13-4665
• Effect of Warm-Mix Technologies and Testing Protocol on Moisture Susceptibility of Asphalt Mixtures
  Abstract: Moisture susceptibility of asphalt mixtures is a commonly addressed concern in mixture designs. As the industry shifts toward the use of warm mix asphalt (WMA) technology from the traditional hot mix asphalt (HMA) there has been increased concern regarding the performance of WMA technology in regards to moisture susceptibility. This concern is primarily driven by the decrease in required production temperatures of the asphalt mixtures which may result in aggregates that have not been dried thoroughly prior to being coated with asphalt binder. To assess this concern, 87 mixtures were evaluated for their resistance to moisture damage using the most common laboratory tests for assessing such damage: AASHTO T 283 and AASHTO T 324. In addition to WMA moisture susceptibility performance, the acceptability of the standard test protocols for moisture testing of asphalt mixtures were evaluated by comparing laboratory performance thresholds to the field performance of the mixtures. As a result of this study, it was determined that there was no statistical difference between field compacted specimens versus laboratory reheated specimens for TSR and HWTD results. WMA consistently showed statistically lower TSR and SIP compared to HMA control mixtures. The current specification criteria for HWTD may need to be adjusted assessing moisture susceptibility of WMA since several mixtures failed in the lab but showed good performance in the field.
  Authors: Leatherman, Kristoffer; Willis, James Richard
  Authors: Leatherman, Kristoffer; Willis, James Richard
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 467
  Paper Number: 13-4673
• Effect of Confinement Pressure on the Nonlinear-Viscoelastic Response of Asphalt Concrete at High Temperatures
  Abstract: Asphalt concrete materials exhibit the nonlinear viscoelastic responses at high stress/strain levels. The traffic loading induces multi-axial stress states within the asphalt concrete pavement structure. Therefore, it is imperative to characterize the nonlinear viscoelastic responses of asphalt concrete under the realistic stress states since these nonlinearities significantly affect the rutting and fatigue damage performance of pavements. Schapery¡¯s (1) nonlinear viscoelastic model has been used extensively by several researchers to characterize the nonlinearity of asphalt concrete materials. However, the available methods for characterizing the viscoelastic nonlinearity are mostly based on the simple uniaxial creep-recovery tests.In this paper, the nonlinear viscoelastic properties of asphalt concrete materials are characterized considering the effects of confinement pressure on the variation of the nonlinear parameters. Dynamic modulus test is used to obtain the linear viscoelastic properties and the time-temperature shift factors. Cyclic creep-recovery tests are performed at high temperature (55¢ªC) and at different confinement levels to characterize the nonlinear viscoelastic responses. The effects of confinement levels and the triaxiality ratio on the variation of the nonlinear viscoelastic parameters are investigated. The analyses show that the confinement pressure and the triaxiality ratio have substantial effects on the nonlinear strain response of the asphalt concrete. The significance of these nonlinear parameters on the complex response of asphalt concrete subjected to different loading conditions is discussed.
  Authors: Rahmani, Eisa; Abu Al-Rub, Rashid K.; Darabi, Masoud K.; Kassem, Emad; Masad, Eyad A.; Little, Dallas N.
  Authors: Rahmani, Eisa; Abu Al-Rub, Rashid K.; Darabi, Masoud K.; Kassem, Emad; Masad, Eyad A.; Little, Dallas N.
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 599
  Paper Number: 13-4735
• Ranking of HMA Moisture Sensitivity Tests in Iowa
  Abstract: Several agencies specify AASHTO T283 as the primary test for field acceptance of moisture susceptibility in hot mix asphalt. When used in this application, logistical difficulties challenge its practicality, while repeatability is routinely scrutinized by contractors. An alternative test is needed which can effectively demonstrate the ability to screen mixtures based on expected performance. The ideal replacement can be validated with field performance, is repeatable, and allows for prompt reporting of results. Dynamic modulus, flow number, AASHTO T283, Hamburg wheel tracking device (HWTD), and the moisture induced sensitivity test (MIST) were performed on plant produced surface mixes in Iowa. Follow-up distress surveys were used to rank the mixes by their performance. The rankings indicate both the quantity of swelling from MIST conditioning and submersed flow number matched the performance ranking of all but one mixture. Hamburg testing parameters also appear effective, namely the stripping inflection point and the ratio between stripping slope and the creep slope. Dynamic modulus testing was ineffective, followed by AASHTO T283 and ratios produced from flow number results of conditioned samples.
  Authors: Schram, Scott Alan; Williams, Ronald Christopher
  Authors: Schram, Scott Alan; Williams, Ronald Christopher
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 467
  Paper Number: 13-4750
• Continuum-Coupled Moisture-Mechanical Damage Model for Asphalt Concrete
  Abstract: Despite the detrimental effects of moisture damage, few macro-scale models exist that are capable of modeling moisture-induced damage in asphalt concrete. These models neither account for the irreversibility of moisture-induced damage nor for time-dependency of moisture damage. In this study, a continuum moisture damage model based on the continuum damage mechanics (CDM) is presented. Both adhesive and cohesive moisture damage phenomena are modeled independently, which allows one to introduce fundamental mechanical properties for each process and model the transition between adhesive and cohesive damage. 2D and 3D simulations are performed and the results of the simulations presented to demonstrate the applicability and utility of these micromechanical computational models. Though the constitutive model presented here is developed to model asphalt concretes as a continua, it is shown that it is well-suited to asphalt mastic, which exhibits time-dependent recoverable and irrecoverable deformations, and degrades with loading and moisture exposure.
  Authors: Shakiba, Maryam; Abu Al-Rub, Rashid K.; Darabi, Masoud K.; You, Taesun; Masad, Eyad A.; Little, Dallas N.
  Authors: Shakiba, Maryam; Abu Al-Rub, Rashid K.; Darabi, Masoud K.; You, Taesun; Masad, Eyad A.; Little, Dallas N.
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 467
  Paper Number: 13-4763
• Use of Variable Rate Spreader Bar to Minimize Wheelpath Bleeding for Asphalt-Rubber Chip Seal Applications
  Abstract: For over thirty five years, the California Department of Transportation (CALTRANS) has been placing Asphalt-Rubber Chip Seals (ARCS) as an effective preventative maintenance strategy, for minor and major road projects, where low and high truck traffic and high pavement temperatures have been prevalent. The performance of chip seals is known to be affected by two critical distresses: (1) raveling, and (2) bleeding, particular in the wheel path. In order to avoid these types of distresses it is critical to select proper application rates of binders and aggregates and to implement a clear quality control plan with effective verification of application rates. Due to the inherent differences in traffic loading in the wheel bath and out of the wheel path, it is commonly observed that most bleeding and flushing is observed in the wheel path. This has prompted the need for varying the application rates between the wheel path and non-wheel path areas. This paper includes a review of several field studies in which both uniform and variable application rate were used to construct Asphalt Rubber Binder chip seals in California. Observation of early (after construction) and late (up to 6 years) performances are reported to show the importance of using a Variable Rate Spreader Bar (VRSB) in mitigating premature bleeding in the wheel path. The study also includes development of a field calibration test method recommended as a modification of the CTM 339-2000 and a recommendation to require the use of a VRSB calibrated according to the newly developed procedure
  Authors: Johannes, Petrina Tutumina
  Authors: Johannes, Petrina Tutumina
  Year: 2013
  Document Type: Paper
  Subject: Maintenance and Preservation; Materials; Pavements
  Session: 654
  Paper Number: 13-4379
• Stiffness Evolution of Granular Materials Stabilized with Foamed Bitumen and Cement
  Abstract: From the literature it is possible to find two trends regarding the stiffness evolution of the Foamed Bitumen Stabilized/Recycled mixtures. The first trend indicates that once the foamed bitumen mix reaches a constant value due to curing process, the stiffness decreases with time due to load cycles. The second trend indicates that stiffness remains constant after curing process. In this research, the stiffness evolution of foamed bitumen mixes stabilized with different bitumen and cement contents is studied. The stiffness was measured using the Indirect Tensile Fatigue Test (ITFT). Results indicate that once the foamed bitumen mix reaches a constant value due to curing process, the stiffness will decrease or keeps constant depending on the stress-level applied to the foamed bitumen layer. If the stress-level is lower than a specific value, the stiffness of the mix will remain constant at a value very close to the initial stiffness. If the stress-level is greater than a specific value the stiffness of the mix will decrease gradually. Also, the reduction rate of the stiffness will be greater as the stress-level is higher. The analysis of results from mixes with different bitumen and cement contents allow identifying the effect of both stabilizing agents in the long-term stiffness.
  Authors: Halles, Felipe; Thenoux, Guillermo; Gonzalez, Alvaro Andres
  Authors: Halles, Felipe; Thenoux, Guillermo; Gonzalez, Alvaro Andres
  Year: 2013
  Document Type: Paper
  Subject: Geotechnology; Materials; Pavements
  Session: 740
  Paper Number: 13-4177
• Evaluation of Semiflexible Composite Mixture Using Indirect Tensile Tests
  Abstract: The main purpose of this paper was to evaluate the engineering properties of Semi-Flexible Composite Mixture (SFCM). A slab SFCM sample was fabricated in the laboratory to simulate the filling of cement mortar in the field. Performance testing was carried out by Indirect Tensile (IDT) mode and using Material Testing System (MTS) equipment. IDT testing has been found to be able to correlate with the field performance of asphalt mixtures at low, intermediate, and high temperatures. They were thus used in this study to evaluate the thermal cracking, fatigue, rutting, as well as moisture resistance of SFCM. A control hot mix asphalt (HMA) mixture was used to compare with the results of SFCM. Based on the testing results, it was found that the designed SFCM showed good filling capability of cement mortar. SFCM had higher dynamic modulus than the control HMA. It had good resistance to rutting and moisture damage. Based on fracture work, SFCM showed better resistance to thermal cracking while lower resistance to fatigue cracking.
  Authors: Zhang, Weiguang; Shen, Shihui; Huang, Hai; Goodwin, Ryan D.
  Authors: Zhang, Weiguang; Shen, Shihui; Huang, Hai; Goodwin, Ryan D.
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 670
  Paper Number: 13-4304
• Evaluation of Dynamic Modulus Predictive Models for Asphalt Mixtures Containing Recycled Asphalt Shingles
  Abstract: Transportation agencies are increasingly using recycled asphalt shingles (RAS) in asphalt pavements for economic and environmental benefits. The primary components of RAS are asphalt, mineral filler, aggregate granules, and either organic or fiberglass fibers. The effect of these components on the dynamic modulus of an asphalt mixture, which is a key input in the Mechanistic-Empirical Pavement Design Guide (MEPDG) and a critical property of asphalt mixtures related to its performance, are still uncertain. As part of National Pooled Fund Study TPF-5(213), a series of experimental plans was conducted utilizing demonstration based paving projects to investigate various factors related to RAS utilization. Thirteen mix designs with RAS contents ranging from zero to six percent were developed and constructed in Indiana, Iowa, Minnesota, and Missouri. Field produced mixtures were procured and sent to Iowa State University¡¯s Asphalt Lab for laboratory dynamic modulus testing. The test results are used in this study to evaluate two commonly used dynamic modulus predictive models, the Witczak and Hirsch models. Two versions of the Witczak models, which were developed in 1999 and 2006, are evaluated in this research. It was found that the Witczak models were not very effective in estimating the modulus values of RAS mixtures. This study concludes that commonly used dosages of RAS in asphalt mixtures affects the prediction accuracies of the Witczak and Hirsch models due to biases of the E* predictive models in terms of input parameters, inaccuracies of input parameter measurements, effects of blend efficiency, and influences of the RAS fibers.
  Authors: Yu, Jianhua; Williams, Ronald Christopher; Cascione, Andrew
  Authors: Yu, Jianhua; Williams, Ronald Christopher; Cascione, Andrew
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 656
  Paper Number: 13-4489
• Evaluating Rut Resistance Performance of Warm-Mix Asphalts in North Dakota
  Abstract: New emerging technologies in asphalt production and placement with the premise of saving fuel, reducing plant emissions, and extending the paving season into colder weather have been gaining popularity in recent years. These technologies, Warm Mix Asphalts (WMA), are produced by incorporating additives into asphalt mixtures that reduce the viscosity of the asphalt binders and allow aggregate coating at temperatures well below of those of the conventional hot-mix asphalt (HMA). Due to the short paving season in North Dakota, North Dakota Department of Transportation (NDDOT) has embarked on WMA research in hopes that the use of WMA will lead to the extension of the paving season into colder weather. Since previous WMA research was not conclusive on rutting and moisture issues, NDDOT constructed WMA and HMA overlays to evaluate the WMA resistance to rutting and moisture sensitivity. The WMA overlay sections were constructed using Evotherm 3G chemical additive.The primary purpose of this research is to evaluate and compare the rut resistance performances of the WMA and HMA overlays under dry and wet conditions. Twenty four core samples representing the WMA and the control HMA sections were tested for rut resistance under dry and wet conditions using the asphalt pavement analyzer (APA). The APA results indicate that the average rut values for WMA mixes were 13 percent and 29 percent higher than those of the HMA mixes under dry and wet conditions, respectively. The elevated rut values of WMA mixes under wet testing would indicate reduced durability of WMA mixes.
  Authors: Suleiman, Nabil; Mandal, Subhash
  Authors: Suleiman, Nabil; Mandal, Subhash
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 704
  Paper Number: 13-4855
• Rheological Characterization of Nanoparticle-Based Biomodified Binder
  Abstract: This paper investigates the effects of nanoparticles (nano -clay and nano -silica) on the rheological characteristics of bio-modified asphalt. It further compares its performance characteristics with those of base asphalt, nano-clay modified asphalt (without bio-binder) and bio-modified asphalt (without nano-particles). As such, the following research hypothesis were investigated: 1) Nano particles will increase bio-modified binder (BMB) complex modulus which in turn increases BMB’s high temperature performance; 2) Nano particles will enhance BMB’s aging resistance, 3) Nano particle will act as a surfactant and stabilizer which will increase the BMB’s viscosity while maintaining mixtures’ workability. The effect of the nanoparticles on workability and high temperature performance of the asphalt binder with and without bio-binder was evaluated by measuring the rotational viscosity and complex shear modulus. The performance of each binder was evaluated for rutting resistance, aging resistance and creep stiffness performance behavior. The results indicated that the addition of nano-clay to bio-modified asphalt helped significantly improve high temperature performance. Correspondingly, the hardening of bio-modified asphalt saw a significant improvement as the percentage of nano-clay was increased. The data indicated that nano-silica improved the viscosity of the bio-modified asphalt binder but had little effect on the aging and rutting resistance of the mixtures. It was observed that nano-silica slightly increased bio-modified asphalt binder complex modulus with a decrease to binder low temperature performance. Overall, the characterization results suggested an improvement to bio-modified asphalt binder high temperature performance with the addition of nanoparticles.
  Authors: Onochie, Albert Chinedu; Fini, Elham H.; Yang, Xu; Mills-Beale, Julian; You, Zhanping
  Authors: Onochie, Albert Chinedu; Fini, Elham H.; Yang, Xu; Mills-Beale, Julian; You, Zhanping
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 596
  Paper Number: 13-4895
• Analysis of RAP with Known Source History and Influence on Fatigue Performance
  Abstract: This study characterized RAP materials milled from the upper layer of three accelerated pavement test lanes that were exposed to climatic conditions over a number of years where the original binder and aggregate properties are known from the time of construction. The aggregates and binder in the RAP were extracted using the both solvents and ignition oven and compared to the construction data to quantify the changes in measured properties. Three mixes containing 0%, 20% and 40% RAP taken from one lane were then designed using virgin asphalt and aggregate materials from the same original source. The three mixes were tested for the dynamic modulus and cyclic direct tension fatigue to investigate the effect of RAP content on the mixture performance with a higher degree of control over the volumetric characteristics of the mix designs.Both solvent and ignition oven extraction resulted in a decrease in the aggregate specific gravity and increase in the absorption compared to original values known during construction. Binder content and gradation from solvent and ignition oven extraction were similar for the two unmodified asphalt RAP sources, but the RAP SBS modified asphalt exhibited closer values to the other two RAP materials using the ignition oven and did not with solvent. Mixes with 20% and 40% RAP could be satisfactorily designed to match the 0% RAP volumetrics. The dynamic modulus fatigue tests showed increasing stiffness, decreasing phase angle and decreasing fatigue resistance with increasing RAP.
  Authors: Li, Xinjun; Gibson, Nelson Harold
  Authors: Li, Xinjun; Gibson, Nelson Harold
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 656
  Paper Number: 13-4901
• Temperature Prediction for Mass Concrete Using Finite Element Method
  Abstract: In this research, large concrete cubes were constructed to study the early temperature distribution inside the concrete. Finite element model was created using ABAQUS to simulate the heat transfer process. To account for the variation of concrete properties during hydration and the fact that heat generation not being uniform inside concrete, user subroutines were developed and incorporated in the model to enable solution dependent material properties and thermal loading function. In this study, there are three major improvements of the finite element method: 1. Material properties are now dependent on degree of hydration and temperature. 2. Thermal loading function is also degree of hydration dependent. 3. Degree of hydration varies at different locations in concrete depending on their unique temperature histories. The method developed in this study is applicable to predict temperature history for mass concrete with better accuracy. Simulation results of temperature field fit well with data collected from the experiments.
  Authors: Lin, Yun; Chen, Roger H. L.
  Authors: Lin, Yun; Chen, Roger H. L.
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 288
  Paper Number: 13-4904
• Pull-off Test for Evaluation of Asphalt Pavement Interface
  Abstract: This paper presents the development process of modified pull-off test for measurement of in-situ pavement interface bonding strength. The modified test method was validated using two case studies (i.e., delaminated vs. non-delaminated pavements on I-65 and intelligent compacted vs. non-intelligent compacted pavements on US-52) and used for developing a correlation model for estimating a probability of delamination failure at a given pull-off bonding strength. In addition, methodologies for probabilistic interpretations with pull-off test results were explored.The results demonstrated that the modified pull-off test showed its applicability in measurement of interface bonding condition with both weak and strong conditions. Additionally, its results revealed the statistically significant difference between pull-off bonding strength between delaminated and non-delaminated pavement sections. Another result was The different compaction practices (with and without employing the IC technology) were a minor factor influencing the interface bond condition of the US-52 test pavement sections. Using the pull-off test results, correlation between the pull-off bonding strength and the delamination was modeled and evaluated by the statistical analysis in this study. Based on the model, the methodologies with threshold-based and severity-based delamination estimation are introduced and deemed to be effective in assessment of pavement condition.
  Authors: Ahn, Hyung Jun; Lee, Jusang
  Authors: Ahn, Hyung Jun; Lee, Jusang
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 655
  Paper Number: 13-4956
• Investigation of Internal Frost Damage in Cementitious Materials with Micromechanic Analysis, Scanning Electron Microscope Imaging, and Ultrasonic Wave Scattering Techniques
  Abstract: This study investigates the internal-frost damage due to ice crystallization pressure in capillary pores of concrete. The SEM imaging analysis, micro-damage modeling and ultrasonic wave scattering techniques were developed to study the internal-frost damage in cementitious material samples. The pore structures have significant impact on freeze-thaw durability of cement/concrete samples. The scanning electron microscope (SEM) techniques were applied to characterize freeze-thaw damage within pore structure. The digital sample was generated from SEM imaging processing. In the microscale pore system, the crystallization pressures at subcooling temperatures were calculated using interface energy balance with thermodynamic analysis. The largest crystallization pressure on the pore wall was input for the fracture simulation with the developed Extended Finite Element Model (XFEM). One comparison study between model simulation and test results indicates that internal-frost damage model can reasonably predict the crack nucleation and propagation within multiphase cement microstructure. In addition, the ultrasonic wave scattering technique was developed for rapid measurement of pore size distribution and volume fraction in cementitious concrete. The inverse analysis results show the promising measurements of size distribution of pores in concrete samples. Future study will link the micromechanics analysis and the ultrasonic wave scattering techniques to study the internal-frost damage evolution.
  Authors: Dai, Qingli; Ng, Kenny; Yu, Xiong
  Authors: Dai, Qingli; Ng, Kenny; Yu, Xiong
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 288
  Paper Number: 13-4966
• Using Gel Permeation Chromatography to Predict Viscoelastic Properties of Recycled Asphalt Shingle Binder and Its Use in RAS Blending Efficiency
  Abstract: Reuse of the asphalt binder from Recycled Asphalt Shingles (RAS) is at the forefront of the industry due to dwindling natural resources and the potential economic benefits. However, the blending efficiency of RAS binder with virgin binder remains unknown to the asphalt industry. This paper conducted research on the correlation between percentages of large molecules (LMS) defined by Gel Permeation Chromatography (GPC) with viscoelastic properties of RAS binders and investigated the blending efficiency of RAS binders based on this relationship. Aggregate size, RAS content and mixing time were evaluated as factors that affect the blending efficiency. The test results showed that percentages of LMS were highly correlated with the complex modulus. Based on GPC test results, increasing mixing time led to better blending of RAS mixture and the size of virgin aggregate didn't affect the blending efficiency. Partial blending was investigated in this study and the best blending efficiency may occur with the addition of around 5% RAS by weight.
  Authors: Zhao, Sheng; Bowers, Benjamin F.; Huang, Baoshan; Shu, Xiang; Woods, Mark
  Authors: Zhao, Sheng; Bowers, Benjamin F.; Huang, Baoshan; Shu, Xiang; Woods, Mark
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 604
  Paper Number: 13-5013
• Temperature Effects on Soil Behavior in Relation to Ground-Sourced Bridge Deck Deicing Systems
  Abstract: The effect of temperature on soil behavior is gaining importance as energy foundations are utilized for heating and cooling of buildings as well as for deicing of bridge decks in the winter. This paper describes the effect of temperature changes on soil behavior. The results of temperature-controlled triaxial tests and oedometer tests from previous studies are evaluated to determine the general trends of soil behavior in response to temperature increase. A comprehensive review of the literature shows that an increase in temperature induces changes in the pore water pressure, volume, shear strength, and preconsolidation pressure of the soil. During an undrained triaxial test, an increase in temperature of 35⁰C can result in excess pore water pressures up to 80% of the initial consolidation pressure. The change in volume during a drained triaxial shear test not only depends on the temperature history but also on the overconsolidation ratio (OCR). Normally consolidated clays exhibit a highly contractive behavior in reponse to increased temperatures during drained loading. Lightly overconsolidated clays (OCR<2) show a smaller thermal contraction than normally consolidated clays during heating. Clays having a high OCR show highly dilative behavior during thermal loads. As overconsolidation ratio increases, clays tend to be more dilative when thermally loaded. The effect of temperature increase on shear strength is a subject of controversy. Many studies indicate that an increase in temperature strengthens the clay. On the other hand, there are also studies that indicate an increase in temperature may cause a slight reduction in clay strength. Another significant effect of temperature change is the way it influences the consolidation state of the soil. By examining the previous studies, it is found that the preconsolidation pressure decrease as the soil temperature increases.
  Authors: Sutman, Melis; Olgun, Guney
  Authors: Sutman, Melis; Olgun, Guney
  Year: 2013
  Document Type: Paper
  Subject: Geotechnology; Materials
  Session: 696
  Paper Number: 13-5022
• Effectiveness of Antistrip Agents in Asphalt Mixtures
  Abstract: Since the late 1970s there has been much research performed to better understand the stripping phenomenon in asphalt mixtures. As a result, there have been changes in both materials and technology over the past 30 years to improve the resistance to moisture damage and the ability to test for performance under adverse moisture conditions. Due to the changes in materials and technologies related to the development and improvement of anti-strip agents, this research study was conducted to evaluate the effectiveness of current anti-strip agents used in hot mix asphalt pavements.The objectives of this project was to construct a field test section that used three different anti-strip agents in a conventional Superpave surface mixture, and conduct a series of laboratory performance test comparisons using different aging periods to make long-term comparisons of the effectiveness of hydrated lime, liquid additive, and Warm mix antistrip additives.Some of the pertinent conclusions from this research study are summarized as follows: - Multiple freeze/thaw cycles of 0, 1, 5, and 10 cycles were used for a portion of the research study. Hydrated lime had the highest tensile strength and highest TSR values and was the only additive treatment to meet the minimum of 80% TSR for all freeze/thaw cycle combinations. - Both 5 and 10 freeze/thaw cycles were significantly more discriminating in regard to moisture susceptibility than one freeze/thaw cycle alone. - WMX treated mixtures produced low initial tensile strengths, but the strength of these mixtures improved with time.
  Authors: Watson, Donald E.; Moore, Jason Roox; Taylor, Adam Joel; Wu, Peter Y.
  Authors: Watson, Donald E.; Moore, Jason Roox; Taylor, Adam Joel; Wu, Peter Y.
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 670
  Paper Number: 13-5061
• Rheology of Asphalt Emulsion Residues and Its Relationship to Elastic Recovery in AASHTO T301
  Abstract: Several researchers investigated the use of dynamic shear rheometer (DSR) based tests to replace elastic recovery test using a ductility bath for PG graded modified asphalt binders. Some studies reported good correlation between percent recovery of multiple stress creep and recovery (MSCR) test (AASHTO TP70) and elastic recovery of AASHTO T301 using a ductility bath for PG binders. In this study, DSR based rheological tests of 20 different asphalt emulsion residues were performed and its relationships with elastic recovery (AASHTO T301) were investigated. Out of 20 emulsions, 8 are hard pen base asphalt emulsions of which 2 are polymer modified. Out of 12 non-hard pen base asphalt emulsions, 6 are polymer modified. In strain sweep test from 2% to 52%, it was observed that emulsions prepared of hard pen base asphalt have relatively lower strain tolerances. Using frequency sweep data, complex modulus master curves were constructed at 25°C for overall rheological behavior. Temperature sweep of phase angle from 52°C to 94°C showed that maximum phase angle in the range of 75° to 85° may be used as a criterion for polymer identification. Burgers model parameters were obtained through fitting of 1st creep and recovery cycle and two parameters, Maxwell viscosity and Kelvin viscosity were investigated for polymer identification. From multiple stress analyses, it was observed that the relationship between creep stress and percent recovery (MSCR) is negative and logarithmic. Finally, the highest coefficient of determination of linear correlation was obtained between MSCR percent recovery at 10°C and elastic recovery (AASHTO T301) at 58°C. Coefficient of determination, R2 values obtained for 0.1 kPa and 3.2 kPa creep stresses are 0.961 and 0.938, respectively. Therefore, MSCR at 10°C has been recommended as a criterion for polymer identification. At 0.1kPa creep stress, a minimum percent recovery of 25 and at 3.2kPa, a minimum percent recovery of 9 is recommended to identify the presence of polymer.
  Authors: Wasiuddin, Nazimuddin Mohammad; Salehi Ashani, Saeid; Kabir, Md Sharear; Abadie, Christopher David; King, William; Mohammad, Louay N.
  Authors: Wasiuddin, Nazimuddin Mohammad; Salehi Ashani, Saeid; Kabir, Md Sharear; Abadie, Christopher David; King, William; Mohammad, Louay N.
  Year: 2013
  Document Type: Paper
  Subject: Maintenance and Preservation; Materials; Pavements
  Session: 654
  Paper Number: 13-5071
• Scanning Laser Detection of Crack Precursors in High RAP Content Asphalt Mixture with Improved Fatigue Performance
  Abstract: Formation of microcracks under fatigue conditions is a complex mechanism and difficult to detect. A microcrack is not apparent until late in fatigue life of the section. However, structural changes and microcracks can occur earlier and could be used as an originator for fatigue crack formations that lead to failure. Therefore, it is important to develop methods to promptly detect microcracks early in fatigue life well in advance of macrocrack growth. This paper presents the test procedure and analysis approach developed for a non-contact Scanning Laser Detection (SLD) for capturing and monitoring cracks in asphalt mixtures. The study focuses on utilizing SLD to investigate damage resistance of asphalt mixtures containing high Recycled Asphalt Pavement (RAP) content. Use of more RAP in asphalt materials is becoming increasingly popular due to the economic and environmental benefits of recycled materials. On the other hand, stiffer mixes resulting from RAP addition has raised concern about long term properties of pavement, therefore an accurate fatigue evaluation of these mixes are needed. The proposed scanning technique detects cracks in initiation and propagation phases and characterizes surface state with a parameter called Defect Frequency (DF). This parameter is used as direct indication of the light scattering signature of specimen and can be related to surface changes leading to crack initiation. For each mixture (50% RAP and a control), the fatigue lives determined from the SLD were compared and exhibited strong correlation with those obtained from the traditional mechanical and energy-based fatigue approaches.
  Authors: Ajideh, Hossein; Bahia, Hussain U.; Earthman, James
  Authors: Ajideh, Hossein; Bahia, Hussain U.; Earthman, James
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 840
  Paper Number: 13-5136
• Field and Laboratory Evaluation of Environmental Effects on Chip Seal Performance: Freeze-Thaw and Asphalt Aging
  Abstract: Chip seals generally deteriorate as a result of asphalt oxidation, wear and polishing of aggregate, bleeding, and raveling (loss of aggregates). In this study, two major environmental effects on chip seal performance, freeze-thaw and asphalt aging were investigated based on laboratory tests and field distress survey. For freeze-thaw evaluation, laboratory chip seal samples were prepared for 18 combinations (6 aggregates X 3 asphaltic materials). A simple freeze-thaw protocol was developed. It was observed that freeze-thaw loss is much higher than post freeze-thaw sweep test and control (dry) sweep test. Evaluation of freeze-thaw effect on aggregate types reveals that both the precoated and uncoated expanded shale lightweight performs comparatively very well against freeze-thaw plus sweep test. Evaluation of freeze-thaw effect on asphaltic materials types reveals that CRS-2P performs better than PAC-15 and AC20-5TR. For aging evaluation, asphaltic materials were extracted from 15 (5 aggregates X 3 asphaltic materials) field test sections and increase in stiffness due to aging were determined using a dynamic shear rheometer. For each of the five aggregates, CRS-2P shows the lowest G*/sinä indicating minimum field aging susceptibility among the three asphaltic materials. For each of the aggregates, AC20-5TR shows slightly higher G*/sinä than PAC-15 indicating maximum field aging susceptibility among the three asphaltic materials used in this study. It is evident from this study that precoating of aggregates increased the aging indices. For the field evaluation, fifteen chip seal test sections were prepared with three asphaltic materials and five aggregates in a 9-acre parking lot. Overall field distress ratings of the CRS-2P sections are better than those of PAC-15 sections and overall distress ratings of PAC-15 (sum of distress ratings of all the PAC-15 sections) sections are better than overall distress ratings of AC20-5TR sections which closely reflect the observations in freeze-thaw evaluation and asphalt aging evaluation.
  Authors: Wasiuddin, Nazimuddin Mohammad; Wilson, Kisler; Islam, Mohammad Readul; Parker, Phillip; Abadie, Christopher David; Mohammad, Louay N.
  Authors: Wasiuddin, Nazimuddin Mohammad; Wilson, Kisler; Islam, Mohammad Readul; Parker, Phillip; Abadie, Christopher David; Mohammad, Louay N.
  Year: 2013
  Document Type: Paper
  Subject: Maintenance and Preservation; Materials; Pavements
  Session: 654
  Paper Number: 13-5094
• Permanent Deformation Charcterization of Asphalt Mixtures Using Incremental Repeated Load Testing
  Abstract: Currently, flow number (FN) test is being used for measuring permanent deformation resistance of asphalt mixtures. The provisional AASHTO TP 79-10 test method specifies the requirements of the FN test; however, there are undefined levels of test parameters, such as temperature, axial stress, and confinement, which have not been addressed. Furthermore, flow number criteria that can reliably discriminate between various mixtures have not been established. In addition, as the asphalt industry continues to develop more sophisticated mixtures, a single FN value is not adequate to capture the true complexity of the asphalt mixtures. These and other shortcomings of the FN test reduce its effectiveness for evaluating high temperature performance of asphalt mixtures. A new high temperature test for evaluation of rutting susceptibility of asphalt mixtures is being proposed. The new test referred to as Incremental Repeated Load Permanent Deformation Test is conducted at one temperature and multiple stresses in four increments, whereas only takes 33 minutes to complete. The property of the test is the strain per cycle at the end of each test increment (minimum strain rate= MSR). A master curve is developed by plotting the MSR values versus a combined temperature-stress parameter. The MSR master curve characterizes the high temperature response of asphalt mixtures at any stress and temperature. The MSR master curve has both laboratory and field applications. The laboratory applications are to evaluate mixture design and to rank various mixtures. The laboratory applications are to predict rut depth and to estimate allowable traffic levels.
  Authors: Azari, Haleh; Mohseni, Alaeddin
  Authors: Azari, Haleh; Mohseni, Alaeddin
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 599
  Paper Number: 13-5160
• Development of Three-Point Bending Single-Edge Notched Beam Interface Bond Test
  Abstract: One of the most substantial parameters influencing performance and service life of a pavement structure is the quality of the bonding between adjacent layers. When a HMA surface layer bonds poorly to the layers below, the ability of the pavement to effectively bear loads and transfer radial tensile and shear stresses from one layer to another reduces significantly leading to different types of distresses in pavement system which can result in reduction of pavement structural integrity. Although significant number of research studies has been directed towards the interface bonding, research of interface bonding using fundamental fracture mechanics is still in its infancy and satisfactory laboratory tests and analyses have yet to be developed. The main objectives of this paper are to describe the selection and development of a three-point bending single-edge notched beam fracture test to evaluate the bonding between adjacent pavement layers and to assess the test through testing of field specimens. Tests were performed to develop test procedure, to investigate test repeatability, to examine variations of interface fracture energy with temperatures and loading rates and to investigate interface bonding in mixed mode. The results from the tests follow expected trends and test variability appears to be within the typical ranges for interface bond tests. The study clearly shows the ability of the test to evaluate the quality of the bonding between pavement layers and to generate fundamental fracture data that can be used in computational models in order to facilitate system optimization and linkage between material properties and field performance.
  Authors: Hakimzadeh, Salman; Buttlar, William G.; Exline, Marvin
  Authors: Hakimzadeh, Salman; Buttlar, William G.; Exline, Marvin
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 655
  Paper Number: 13-5217
• Development of Predictive Model for Skid Loss of Asphalt Pavements
  Abstract: Pavement friction is one of the primary factors that affect highway safety. Pavements with adequate surface friction reduce the number of wet skidding crashes. The objective of this study is to develop a predictive model for friction loss of pavement surface. The model incorporates parameters that describe aggregate shape characteristics, aggregate resistance to abrasion and polishing, aggregate gradation, and polishing cycles. This model was developed based on the results of a comprehensive experimental program. Square-shape slabs of different asphalt mixtures were prepared in the laboratory using a linear kneading compactor and polished using a wheel-polishing device. The frictional characteristics of the surface of the test slabs were measured after different intervals of polishing and statistical analysis was performed to relate friction to mixture characteristics.
  Authors: Kassem, Emad; Awed, Ahmed; Masad, Eyad A.; Little, Dallas N.
  Authors: Kassem, Emad; Awed, Ahmed; Masad, Eyad A.; Little, Dallas N.
  Year: 2013
  Document Type: Paper
  Subject: Materials; Pavements
  Session: 517
  Paper Number: 13-5229
• Development of Predictive Model for Laboratory Compaction of Asphalt Mixtures
  Abstract: Compaction significantly influences the performance of asphalt mixtures. Insufficient compaction often leads to excessive premature permanent deformation, excessive aging, and/or moisture damage. This study aimed to develop a prediction model for laboratory compaction of asphalt mixtures. This predictive model was developed based on parameters that describe aggregate shape characteristics, aggregate gradation, binder content, and binder properties as a function of compaction temperature. Results from intensive laboratory experiments that were used to quantify the effect of these parameters on the compaction of asphalt mixture in the laboratory are reported. Analysis of these test results show that the asphalt mixture type, aggregate type, and binder content have a significant and substantial effect on the slope and intercept values of the laboratory compaction curves. Two models that describe both slope and intercept of the laboratory compaction curves of asphalt mixtures are presented. These models show strong correlations between the predicted values and the measured ones. The models provide essential inputs that can be used to quantify the compaction effort needed to compact HMA in the laboratory.
  Authors: Awed, Ahmed; Kassem, Emad; Masad, Eyad A.; Little, Dallas N.
  Authors: Awed, Ahmed; Kassem, Emad; Masad, Eyad A.; Little, Dallas N.
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 826
  Paper Number: 13-5250
• Moisture Susceptibility Evaluation of Warm-Mix Asphalt Concrete Using Cyclic Direct Tension Tests and Digital Imaging Analysis
  Abstract: This paper presents the simplified viscoelastic continuum damage (S-VECD) material model, based on cyclic direct tension testing and layered viscoelastic analysis (LVEA), for the evaluation of moisture susceptibility of asphalt concrete. The visual stripping inspection afforded by digital imaging analysis is also proposed as an intuitive and straightforward method for moisture susceptibility evaluation. These methods are applied to a Superpave 19 mm hot mix asphalt (HMA) mixture and corresponding warm mix asphalt (WMA) mixtures modified by a polyethylene wax-type additive with and without an anti-stripping agent. It is found that the fatigue life predicted by the S-VECD and LVEA models has a strong correlation with the percentage of stripping determined from specimen surfaces that have been fractured during cyclic direct tension testing of the HMA and WMA mixtures with various asphalt contents. Finally, a polyethylene wax-type additive combined with an anti-stripping agent is found to provide a longer fatigue life and less stripping than a pure polyethylene wax-type additive. The findings from this paper should provide guidance to agencies and material engineers in developing asphalt binder modifiers that lengthen the fatigue life of pavements and reduce moisture susceptibility.
  Authors: Lee, Jong-Sub; Lee, Jae-Jun; Kwon, Soo-Ahn; Kim, Y. Richard
  Authors: Lee, Jong-Sub; Lee, Jae-Jun; Kwon, Soo-Ahn; Kim, Y. Richard
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 655
  Paper Number: 13-4695
• Effect of Crumb Rubber-Modified Dissolution on Storage Stability of CRM-Modified Asphalt
  Abstract: Crumb Rubber Modified Asphalt (CRMA) extensively suffers from high temperature storage instability. Because of the higher density of the CRM particles, they are settling down to the bottom of storage tanks and increase the complex modulus of the samples taken at the bottom. Under different interaction parameters and consequently different mechanism of interactions the storage stability index of the CRMA changes. In this research, the effect of both CRM dissolution in asphalt and the viscosity of the liquid phase of the CRMA on its storage stability were investigated. Dissolution of CRM in asphalt was controlled through regulating interaction temperature, interaction mixing rate, interaction time and CRM concentration. Standard storage stability test was conducted on CRMA samples to measure the corresponding Storage stability Index (SI). Viscosity of the liquid phase of CRMA samples was measured at the same temperature of the storage stability test (163¢ªC), using a Rotational Viscometer (RV), to study the viscosity development process of liquid phase and its effect on storage stability. Composition analysis was conducted using a Thermo-Gravimetric Analysis (TGA) to investigate the effect of changes in CRM composition on the storage stability of CRMA. Results reveal that, in addition to the CRM particle size, the change in viscosity of the liquid phase and the composition of CRM affect the storage stability of the CRMA. Moreover, increasing the dissolution of CRM at intermediate interaction temperatures can improve its storage stability significantly.
  Authors: Ghavibazoo, Amir; Abdelrahman, Magdy; Ragab, Mohyeldin Safwat
  Authors: Ghavibazoo, Amir; Abdelrahman, Magdy; Ragab, Mohyeldin Safwat
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 596
  Paper Number: 13-4939
• Strength at Early Age and Shrinkage Behavior of High Performance Concrete
  Abstract: In recent decades, High Performance Concrete (HPC) has been used in bridge decks due to its enhanced strength and durability compared to traditional concrete. However, during deck replacement project where the traffic is controlled by full or partially lane closure, it has been shown that truck loads cause cracking in HPC at early age. There is a need for an early age HPC with high strength to help mitigate the cracks while maintaining shrinkage properties.The objective of this paper is to investigate the effect of accelerator and shrinkage reducing admixture on the early age (e.g., 8-24 hours) strength as well as the drying free shrinkage of HPC including slag as a replacement. This work was performed as a part of an overall study for the New Jersey Turnpike Authority (NJTA) to develop technical specifications for high early strength-high performance concrete (HES-HPC) applied to concrete decks during staged construction. In this study, six different slag mixes including set-accelerating admixture and shrinkage reducing admixture were tested at early age (e.g., 8 and 12 hrs.) to a later age at 56 days. Results show that higher accelerator dosages with 14-day wet-curing conditions increase the early age strength, without adverse effects on the drying free shrinkage. Additionally, higher accelerator dosages in conjunction with dry-curing conditions caused drying shrinkage strains higher than the specified limits.
  Authors: Na, Chaekuk; Nassif, Hani; Johnsen, W. Scott
  Authors: Na, Chaekuk; Nassif, Hani; Johnsen, W. Scott
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 290
  Paper Number: 13-4986
• Thermally Induced Water Flux in Soils
  Abstract: This paper presents a comprehensive study for the formulation of the thermally induced water flux. For conditions without ice lenses, either frozen or unfrozen conditions, a theory was proposed to address the underestimation of water flux by the model of Philip and de Vries (1). In addition, experiments with a modified capillary rise method were proposed to calculate a gain factor, which accounts for this underestimation. For the thermally induced flux in frozen soils with ice lenses, a theoretical formulation was derived for the segregation potential, which is the key parameter in the model of Konrad and Morgenstern (22-24). This theoretical formulation, which is absent in previous research, is expressed in a simple mathematical form and can be conveniently used for accurate prediction of segregation potential. The validity of the theory was proven with reported data. And more auxiliary relationships were provided for accurately predicting the segregation potential with the proposed formulation.
  Authors: Liu, Zhen; Zhang, Bin; Yu, Xiong; Tao, Junliang; Sun, Ye; Gao, Quan
  Authors: Liu, Zhen; Zhang, Bin; Yu, Xiong; Tao, Junliang; Sun, Ye; Gao, Quan
  Year: 2013
  Document Type: Paper
  Subject: Geotechnology; Materials
  Session: 696
  Paper Number: 13-5149
• Design, Construction, and Performance of Mastic Asphalt Concrete for Orthotropic Bridge Decks
  Abstract: Mastic asphalt concrete is traditionally applied to the steel deck pavement for an orthotropic bridge. Since mastic asphalt concrete is poured into place and required no compaction, it is essential to develop the material especially for paving applications. The purpose of this research project is to characterize the engineering properties of mastic asphalt concrete and analyze the immediate and long-range performance of the paving system. Test results in the laboratory indicated that an increase in the Trinidad Lake Asphalt (TLA) content led to an increase in the softening point of mastic asphalt concrete. Morphology obtained from scanning electron microscopy showed that asphalt, TLA and mineral fillers were uniformly mixed. The properties and relative proportions of binders and mineral fillers significantly affected the engineering behavior of mastic asphalt concrete. The surface characteristics of aggregate were shown to play a key role in rutting resistance. Testing procedures were developed to design a mastic asphalt mixture for field construction. Practical experiences on the production and construction practices of mastic asphalt concrete were provided. The performance of mastic asphalt concrete was evaluated.
  Authors: Chen, Jian-Shiuh; Chen, Shih-Fan; Liao, Min-Chih
  Authors: Chen, Jian-Shiuh; Chen, Shih-Fan; Liao, Min-Chih
  Year: 2013
  Document Type: Paper
  Subject: Bridges and Other Structures; Materials
  Session: 651
  Paper Number: 13-0404
  Practice-Ready: Yes
• Evaluation of Drilled Shafts with Self-consolidating Concrete
  Abstract: In this study, drilled shafts with self-consolidating concrete (SCC) were prepared and tested using cross-hole sonic logging (CSL). SCC has very high workability. It was placed in the drilled shafts of the bridge on Route 28 over Broad Run in Bristow in Prince William County, Virginia. During placement, properties of the fresh concrete were tested and specimens were prepared to determine the hardened properties. The integrity of the bridge shafts within the reinforcing cage was determined using CSL. Another sonic method, the sonic echo/impulse response (SE/IR) was used to evaluate several test shafts. Also, the use of acousto-ultrasonic (AU) measurements to determine the cover depth outside the reinforcing cage was evaluated during laboratory testing. The results indicated that SCC is highly desirable for drilled shafts; it flows easily, filling the hole, and the removal of the temporary casing is facilitated by this highly workable material. CSL is a satisfactory nondestructive method to determine the integrity of shafts. SE/IR also showed promise as a method that complements CSL for determining the integrity of a shaft. AU test was promising in the laboratory, but needs further development for implementation in the field.
  Authors: Ozyildirim, Celik; Sharp, Stephen R.
  Authors: Ozyildirim, Celik; Sharp, Stephen R.
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 286
  Paper Number: 13-1086
  Practice-Ready: Yes
• Guidelines for Selection and Use of Recycled Concrete Aggregates in Structural Concrete
  Abstract: This paper presents guidelines for using RCA as a full or partial replacement for natural coarse aggregate in new concrete (RCA concrete). Several international standards and guidelines for the use of RCA in concrete are reviewed and contrasted to identify areas where further development is required. The main results of an extensive experimental research program by the Authors are summarized herein to provide the basis for the development of a framework for using RCA in structural concrete. Several RCA performance classes are proposed each with a specific set of requirements and suitable applications. The proposed performance classes define further requirements and guidance for the use of RCA beyond the requirements of CSA A23.1 and ASTM C33. A detailed decision tree is proposed that allows engineers, concrete producers, aggregate suppliers and contractors to assess whether a particular RCA source is suitable for use in reinforced concrete, plain concrete or as a fill material.
  Authors: Butler, Liam J; Tighe, Susan Louise; West, Jeffrey S
  Authors: Butler, Liam J; Tighe, Susan Louise; West, Jeffrey S
  Year: 2013
  Document Type: Paper
  Subject: Geotechnology; Materials; Pavements
  Session: 284
  Paper Number: 13-1173
  Practice-Ready: Yes
• Evaluating Laboratory Compaction Techniques of Reclaimed Asphalt Pavement
  Abstract: Reclaimed Asphalt Pavement (RAP) is a byproduct of roadway resurfacing. A limited amount can be recycled into new hot mix asphalt; the rest is stockpiled. Some states allow the use of RAP/aggregate blends as base course material. Due to its low strength and susceptibility to creep deformation the Florida Department of Transportation (FDOT) excludes RAP as pavement base course for high traffic areas. The research objective was to determine whether the strength characteristics of RAP could be improved through compaction to make it base suitable in high traffic areas. Modified Proctor, vibratory, and gyratory compaction data was compared. Four RAP sources were used. Specimens compacted by the three methods were tested using Limerock Bearing Ratio (LBR), Unconfined Compressive, and Indirect Split Tensile strength. LBR is Florida’s variation of the California Bearing Ratio. Specimens were compacted to either a density or to a compaction energy level. Vibratory compaction produced the lowest densities and strengths. Modified Proctor produced higher densities and strengths than vibratory but the LBR strengths for all RAP types were consistently below FDOT standards. Gyratory compaction produced the highest densities and strengths. Gyratory specimens of RAP were two to four times stronger than modified Proctor specimens at the same density. Compaction method did not have as significant an effect on creep, although gyratory compacted samples did produce less creep than modified Proctor compacted samples.
  Authors: Cosentino, Paul J.; Bleakley, Albert M.; Perersen, Andrew James; Sajjadi, Amir Mohammad
  Authors: Cosentino, Paul J.; Bleakley, Albert M.; Perersen, Andrew James; Sajjadi, Amir Mohammad
  Year: 2013
  Document Type: Paper
  Subject: Geotechnology; Materials; Pavements
  Session: 564
  Paper Number: 13-1220
  Practice-Ready: Yes
• Long-Term Performance of High-RAP Pavements: Case Studies
  Abstract: This paper presents the summary of findings of several case studies on the long term performance of high recycled asphalt pavement (RAP) sections. The goal of this study was to provide the paving community with documentation on the long term performance of high RAP roadway sections compared to that of virgin sections using available information. Roadway sections which contained more than 20% RAP and that had been in place for at least 10 years were identified from across the United States with the help of the local agencies. The long term performances of these various recycled sections were compared directly to mixtures made with similar virgin materials via measurements of distress criteria. These distress criteria included rutting, cracking, ride quality, and any overall performance rating that the local agencies used in evaluating their pavement sections. The virgin sections were placed in the same general location and time frame as the recycled sections. The high RAP sections on average tend to exhibit a lower ride quality, more cracking, and better rutting resistance than the virgin sections but the differences are not always statistically significant. The differences between the performance ratings for RAP and virgin pavements were within 5-10 percent. Overall, pavement sections utilizing high RAP perform at a level comparable to that of virgin sections in these case studies.
  Authors: Anderson, Evan; Daniel, Jo Sias
  Authors: Anderson, Evan; Daniel, Jo Sias
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 656
  Paper Number: 13-1264
  Practice-Ready: Yes
• Cementitiously Stabilized Materials Using Ultrasonic Testing
  Abstract: The effect of curing time, and compaction cementitiously stabilized materials (CSM) was studied using ultrasonic P-wave propagation. In general, the P-wave velocity measurements the mixtures increased with curing time. The trend between unconfined compression strength (UCS) with dry density or compaction water content was the same as the trend with P-wave velocity measurements. For stabilized fine-grained soils, there was a peak in P-wave velocity coinciding with the maximum dry density. The P-wave velocity and constrained modulus were strongly correlated to the UCS for CSMs. A model for prediction of UCS was proposed and verified. These test results provides insights for use of ultrasonic pulse velocity testing method for the determination of mechanical properties of CSM.
  Authors: Su, Zhipeng
  Authors: Su, Zhipeng
  Year: 2013
  Document Type: Paper
  Subject: Geotechnology; Materials; Pavements
  Session: 564
  Paper Number: 13-1435
  Practice-Ready: Yes
• Maintenance Cost Justification for Chloride Treatment and Aggregate on Unsealed Roads
  Abstract: Treating aggregate surfaced roads with chloride dust suppressants or building them up by adding good quality surfacing aggregate is generally believed to reduce surface maintenance costs by creating a more durable surface. This paper quantifies reductions in routine blade maintenance costs by analyzing nearly seven years of cost data from the Johnson County (Wyoming) Road and Bridge Department.Over the past decade, Johnson County has experienced considerable oil and gas drilling, substantially impacting the county’s aggregate surfaced roads. Initial analyses assess the expenditures on the county’s unsealed road network’s highest volume roads, with an average of around 350 vehicles per day and a very high proportion of heavy trucks. The average annual cost of $9,167 per mile per year [$5,696/km-yr] to maintain these roads is high for an unsealed road, but the traffic volume is also high. The county’s maintenance cost data was used to perform a regression analysis with the time since aggregate addition and the time since calcium chloride treatment along with traffic and precipitation as independent variables to generate a model that predicts routine blade maintenance costs. This model predicts cost savings as a percent of the initial chloride treatment cost. Savings range from 24% at 200 vehicles per day to 79% at 650 vehicles per day. This represents only part of the benefits from these treatments, since lower user costs, safer roads, environmental benefits, and lowered aggregate replacement frequency are additional but currently unquantified benefits from good quality aggregate and dust suppression.
  Authors: Huntington, George; Ksaibati, Khaled
  Authors: Huntington, George; Ksaibati, Khaled
  Year: 2013
  Document Type: Paper
  Subject: Geotechnology; Materials; Pavements
  Session: 740
  Paper Number: 13-1543
  Practice-Ready: Yes
• Low-Cost Techniques for Improving Surface Durability of Pervious Concrete
  Abstract: This paper presents the results of a laboratory study to improve the durability of pervious concrete using readily available and low cost techniques. Surface raveling of pervious concrete is a concern for long term use and remediation techniques have not previously been investigated. In this study a high void content pervious concrete was cured in worst case hot and dry conditions to produce poor surface durability. Pervious concrete mixtures included a traditional binder and one which included a super absorbent polymer for internal curing. Various remediation methods including overlaying with fresh pervious concrete, latex paint, epoxy, and a surface densifier were applied to the pavement before abrasion testing using the ASTM C944 rotary cutter method. Results showed that the internally-cured mixture had superior durability to the traditional mixture. Of the surface applied techniques, epoxy provided the best improvement in durability followed by latex paint and the densifier. Material analysis showed that modifying a mixture to include super absorbent polymer was the lowest cost option. On a poorly performing pervious pavement, latex paint or a thin overlay both had low material costs. The summary concludes that low-cost methods are effective techniques to improve the surface durability of pervious concrete.
  Authors: Kevern, John T.; Sparks, Joseph Dan
  Authors: Kevern, John T.; Sparks, Joseph Dan
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 287
  Paper Number: 13-1573
  Practice-Ready: Yes
• Bond Characteristics of Engineered Cementitious Composite Overlays
  Abstract: Rigid concrete overlays have been used for smoothing a damaged surface and/or restoring or improving the mechanical capacity of bridge-decks for many years. The superior ductility with high strength and improved durability characteristics suggest that Engineered Cementitious Composites (ECC) could be used as an attractive alternative to conventional overlay materials, and solutions if a strong mechanical bond is formed between the overlay and the substrate material. An experimental study was performed to evaluate the bond strength between ECC overlay and an ordinary concrete substrate with different types of surface textures including, smooth and rough. Micro-silica concrete (MSC), generally used as an overlay material, were also prepared as a control mixture. ECC and MSC overlay mixtures were cast over the concrete substrate to determine bonding performances. Two test methods; slant shear and splitting prism tests with MSC and two ECC mixtures were used. The experimental results show that when ECC is used as an overlay material, bond strength is significantly increased compared to those of MSC. Under compression loading (slant shear test), the bond strength properties of layered ECC-substrate concrete cylinder specimens is greater than the strength of substrate concrete with compressive strength of around 30 MPa. However, in the case of layered MSC-substrate concrete cylinder specimen, failure consistently occurs at the interface.
  Authors: Sahmaran, Mustafa; Yucel, Hasan Erhan; Al-Emam, Muhannad; Yaman, Ismail Ozgur; Guler, Murat
  Authors: Sahmaran, Mustafa; Yucel, Hasan Erhan; Al-Emam, Muhannad; Yaman, Ismail Ozgur; Guler, Murat
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 288
  Paper Number: 13-1578
  Practice-Ready: Yes
• Internal Curing of Concrete Bridge Decks in Utah: Preliminary Evaluation
  Abstract: The objectives of this research were to 1) monitor in-situ bridge deck properties such as moisture and diffusivity for both conventional concrete and concrete containing pre-wetted lightweight fine aggregate (LWFA), which is intended to provide internal curing, 2) compare deck performance in terms of early-age cracking, and 3) evaluate the concrete mixtures in the laboratory in terms of compressive strength and chloride permeability using cylinders cast in the field at the time of deck construction. The research scope included four bridges, two constructed using conventional concrete and two containing pre-wetted LWFA, in northern Utah. Data from sensors embedded in the concrete decks indicate that the moisture content of the internally cured concrete was 2 to 3 percent higher at 28 days than the moisture content of the conventional concrete. Although the internally cured concrete had a higher moisture content, the electrical conductivity values were approximately the same for all the decks after a couple of months, suggesting that the two types of concrete have similar diffusivity. At 28 days, the average strength of the internally cured concrete was 1 percent higher than that of the conventional concrete, and the internally cured concrete passed between 2 and 30 percent less current during the rapid chloride permeability test than the conventional concrete. After 2 months, three to five cracks about 0.2 to 0.3 mm in width were found on each of the conventional concrete bridge decks, while no visible signs of cracking were found in the bridge decks with internal curing.
  Authors: Guthrie, W. Spencer; Yaede, Joseph M.
  Authors: Guthrie, W. Spencer; Yaede, Joseph M.
  Year: 2013
  Document Type: Paper
  Subject: Construction; Materials; Pavements
  Session: 799
  Paper Number: 13-5374
• Moisture-Sensitive and Stress-Dependent Behavior of Pavement Unbound Materials from In Situ Falling-Weight Deflectometer Tests
  Abstract: In an instrumented flexible pavement with subsurface drainage system, a field study was performed to investigate the influence of water on the response of the pavement structure. The drainage system of the structure was clogged during a three month period, allowing the water table to rise and the structure to undergo high moisture conditions. Thereafter the drainage was reopened allowing the structure to approach its previous hydrological equilibrium state. Along with subsurface groundwater level and moisture content monitoring, the structural response of the pavement was studied by conducting frequent Falling Weight Deflectometer measurements with multilevel loads. The stress sensitivity of the unbound layers and the influence of moisture on their stiffness were studied using the data with an effort to determine the unbound materials nonlinear parameters through a backcalculation algorithm. The study showed that the response of the pavement moisture content to changes in drainage system condition was very fast. The rise in the groundwater level significantly affected the overall stiffness of the pavement structure and the backcalculated stiffness of the unbound layers decreased as their moisture content increased. It was further observed that the unbound layers exhibited stress dependent behavior to multilevel loads. The granular layer showed stress hardening behavior but the subgrade showed stress softening response in unsaturated condition and stress independent behavior in saturated state. Backcalculation of the unbound nonlinear parameters according to the universal extended k ? model revealed that the k1 parameter decreased with increasing moisture content for both the unbound granular layer as well as unsaturated fine grained subgrade material.
  Authors: Salour, Farhad; Erlingsson, Sigurdur
  Authors: Salour, Farhad; Erlingsson, Sigurdur
  Year: 2013
  Document Type: Paper
  Subject: Geotechnology; Materials; Pavements
  Session: 293
  Paper Number: 13-1936
  Practice-Ready: Yes
• Experimental Evaluation of Shear Resistance of Improved Steel-Asphalt Interfaces
  Abstract: Although steel orthotropic deck is currently the most widely adopted solution for long-span bridges, the poor adhesion to the upper asphalt layers still represents a serious problem with a not clear solution. In recent decades many techniques, which involve the use of special bituminous bonding coats, reinforced asphalt membranes, net-reinforced steel deck surfaces or epoxy asphalt binders, have been applied, with varying results, to improve the level of adhesion of the asphalt pavement to the steel surface. In this experimental study two of such techniques were adopted in order to investigate the shear resistance of steel-asphalt pavement systems. The first technique uses epoxy asphalt both as a bonding coat and as a binder of the upper asphalt layer while the second technique concerns the use of a reinforced asphalt membrane that is applied on the steel deck before overlaying with conventional HMA.The ASTRA shear test device was used in order to evaluate the shear resistance of different types of HMA-steel interfaces and to investigate the effects of temperature and normal stress. The results have been compared with the shear properties of bitumen-coated interfaces, studied in a previous research. The results showed that epoxy asphalt guarantees high performance regardless of the test temperature. On the other hand, the shear resistance of the system with the asphalt membrane is lower than with the epoxy asphalt, although it is higher than the resistance of bitumen-coated interfaces at high temperatures.
  Authors: Bocci, Edoardo; Canestrari, Francesco
  Authors: Bocci, Edoardo; Canestrari, Francesco
  Year: 2013
  Document Type: Paper
  Subject: Bridges and Other Structures; Materials
  Session: 651
  Paper Number: 13-1938
  Practice-Ready: Yes
• Reducing Specimen Size of Concrete Flexural Strength Test for Safety and Ease of Handling
  Abstract: This study examines the feasibility of using smaller size concrete beam specimens for conducting flexural strength of concrete, using simple beam with third-point loading, according to AASHTO T97 procedure. A total of 22 mixtures, containing four different coarse aggregates (limestone, diabase, gravel and granite) with maximum size varying from ¾ in to 1.5 inch, were prepared. A total of 132 4x4x14 inch specimens and 132 6x6x21 inch standard specimens size were tested. The 4x4 inch specimens yielded higher flexural strengths, as expected from the literature review. Analysis of the flexural strength test data revealed a very good correlation between the smaller and standard size beams. A model is proposed to convert the flexural strength of the small size specimen to flexural strength of the standard size specimen.
  Authors: Ardani, Ahmad Allen; Tanesi, Jussara; Leavitt, John
  Authors: Ardani, Ahmad Allen; Tanesi, Jussara; Leavitt, John
  Year: 2013
  Document Type: Paper
  Subject: Construction; Materials; Pavements
  Session: 427
  Paper Number: 13-1986
  Practice-Ready: Yes
• Isothermal Calorimetry as a Tool to Evaluate Early-Age Performance of Fly-Ash Mixtures
  Abstract: This paper documents the use of an isothermal calorimeter as scanning tool to evaluate early age behavior of high volume fly ash (HVFA) mixtures. A series of paste and mortar mixtures containing different fly ashes (one Class C fly ash and two Class F fly ashes) with replacement levels ranging from 20% to 60%, with high and low alkali cement were evaluated. Materials testing included ASTM C109, compressive strength of mortar cubes at different ages; ASTM C1437, flow; ASTM C403, time of setting and ASTM C1679, isothermal calorimetry. In most cases, for the same water-binder ratio (0.40) and replacement level, Class C fly ash mixtures exhibited higher strength but delayed setting when compared with Class F fly ash mixtures. Isothermal calorimetry proved to be a good scanning tool for prediction of setting time, early age compressive strength and identifying materials incompatibility.
  Authors: Tanesi, Jussara; Ardani, Ahmad Allen
  Authors: Tanesi, Jussara; Ardani, Ahmad Allen
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 286
  Paper Number: 13-1987
  Practice-Ready: Yes
• Ruggedness Study of Coefficient of Thermal Expansion of Concrete Test Method AASHTO T336
  Abstract: A ruggedness study on AASHTO T336 was performed in order to evaluate the most likely factors to affect the test results. Seven factors were evaluated: time at temperature extremes, water level, position of the LVDT, number of segments, saturation criterion, specimen length and temperature of the first segment. Four laboratories participated and a total of five commercially made CTE devices from two different manufacturers were used. Two different concrete mixtures were used in this study. Based on the results obtained, saturation criterion was found to be the most significant factor. All the other factors, either were found not to have a significant impact on the tests results, have already been addressed in the most current version of the test method or, in the authors’ opinion don’t need to be addressed.
  Authors: Tanesi, Jussara; Gudimettla, Jagan M.; Crawford, Gary L.; Ardani, Ahmad Allen
  Authors: Tanesi, Jussara; Gudimettla, Jagan M.; Crawford, Gary L.; Ardani, Ahmad Allen
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 206
  Paper Number: 13-2167
  Practice-Ready: Yes
• Leaching Behavior of Aluminum, Arsenic, and Chromium from High-Carbon Fly-Ash Amended Highway Structural Fills
  Abstract: Coal power plants are very important in production of electricity in the United States. Approximately 50% of the electricity in Unites States is generated by coal combustion processes. As a result of this, large amounts of coal combustion byproducts, particularly fly ashes, are produced annually. Only 40% of these fly ashes can be reused successfully. The majority of the remaining landfilled or stockpiled fly ashes are high carbon fly ashes (HCFA). Continuous disposal of these HCFAs cause significant environmental and economical problems andhighway structures pose great potential for use of these landfilled HCFAs. While mechanical properties of the fly ash-amended highway base layers and embankments are deemed satisfactory, one key issue that precludes highway embankments built with fly ash is the potential for groundwater impacts caused by metals in the fly ash. To evaluate the environmental suitability, a series of column leach tests were conducted to determine the leaching of metals (Al, As and Cr) from fly ash amended soils. In addition, numerical computer modeling programs were used to predict the metal concentrations in soil vadose zone and groundwater. Results from laboratory tests indicated that metal concentrations increased with an increase in fly ash content and do not exceed the maximum concentration limits for drinking waters with few exceptions. Numerical modeling techniques predicted that leached metal concentrations decreased in the soil vadose zone with time and predicted concentrations of leached metals were below the environmental regulatory limits.
  Authors: Cetin, Bora; Aydilek, Ahmet H.; Li, Lin
  Authors: Cetin, Bora; Aydilek, Ahmet H.; Li, Lin
  Year: 2013
  Document Type: Paper
  Subject: Geotechnology; Materials
  Session: 746
  Paper Number: 13-2251
  Practice-Ready: Yes
• Leaching of Alkaline Substances and Heavy Metals from Recycled Concrete Aggregate Used as Unbound Base Course
  Abstract: There is an increased trend towards use of recycled concrete aggregate (RCA) in construction. However, concerns have been expressed about the highly alkaline leachate from RCA in laboratory studies and associated high-pH leaching patterns and heavy metal release from RCA (e.g., Cr, Pb, and As). In this study, seven samples of RCA from a wide geographical area were investigated. Physical, chemical, and mineralogical properties were characterized, and laboratory column leaching tests were conducted. Two field test sites were installed and instrumented, one at the MNROAD facility in Minnesota and a second at surface parking facility on the campus of the University Wisconsin-Madison. The MNROAD site showed a neutral leachate pH between 6.5 and 8.0 after 7 months of service life (1.2 pore volumes of flow); however, pH from column leaching tests ranged between 11.0 and 12.5 and showed no decline over 100 pore volumes of flow (PVF). Due to the large difference between the field and laboratory results, two samples of RCA in Wisconsin, one from a recent demolition of concrete pavement (WR-F) and the other from an RCA stockpile with an age of 5-10 years (WR-SP), were used in the Wisconsin field site to verify the Minnesota data and investigate the long-term leaching of alkaline compounds and heavy metals. WR-F RCA started with a high leachate pH (12.6) and remained constant for the first 5 pore volumes of flow (PVF); however, WR-SP RCA started at a lower pH (7.3) but with a gradually increasing trend, up to pH = 11.9 for the first 2 PVF. The pH from both RCAs were higher than the USEPA drinking water standard. Arsenic, chromium, lead, and selenium in the RCA field leachate were also observed to be higher than the maximum contaminant level (MCL) for the USEPA drinking water standard.
  Authors: Chen, Jiannan; Tinjum, James M.; Edil, Tuncer B.
  Authors: Chen, Jiannan; Tinjum, James M.; Edil, Tuncer B.
  Year: 2013
  Document Type: Paper
  Subject: Geotechnology; Materials
  Session: 746
  Paper Number: 13-2412
  Practice-Ready: Yes
• Mechanistic Structural Properties of Foamed Asphalt Stabilized Base Materials
  Abstract: Foamed asphalt stabilized base (FASB) combines reclaimed asphalt pavement (RAP) and/or recycled concrete (RC) with a foamed asphalt binder. The pavement structural properties of FASB fall somewhere between conventional graded aggregate base (GAB) and hot mix asphalt (HMA). When FASB is used in place of GAB, the required thickness of the pavement section can be reduced, resulting in cost savings in addition to recycling benefits. The objective of this study is to address the most important performance related parameters of FASB material: stiffness and permanent deformation resistance, particularly with regard to the new mechanistic-empirical pavement design guide (MEPDG). Triaxial dynamic modulus tests were performed on cores of a field compacted and cured FASB mixture consisting of 40% RAP+ 60% RC+ 2.8% foamed asphalt to assess the distinct behavior of FASB under triaxial dynamic loading. Evaluation of the effects of stress states (confining pressure, and deviator stress), loading rate, and temperature on DYNAMIC MODULUS found that loading rate and temperature were the most significant factors influencing FASB stiffness. Insights were also gained regarding the influence of construction and curing conditions in the field. Triaxial repeated load permanent deformation (RLPD) tests were also performed to assess the resistance of FASB material to rutting. The results suggest satisfactory resistance of FASB material to rutting.
  Authors: Khosravifar, Sadaf; Schwartz, Charles W.; Goulias, Dimitrios
  Authors: Khosravifar, Sadaf; Schwartz, Charles W.; Goulias, Dimitrios
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 597
  Paper Number: 13-2544
  Practice-Ready: Yes
• Measurement and Prediction of Coefficient of Thermal Expansion for Concrete Pavement Design in Georgia
  Abstract: The study to investigate the relationship between Coefficient of Thermal Expansion (CTE), aggregate type, gradations, and proportion of coarse and fine aggregate in mixture was conducted using the American Association of State Highways and Transportation Officials (AASHTO) T 336-11. Concrete specimens were fabricated in the laboratory to produce different mixes using Type I cement. Mix design variables were coarse and sand aggregate types, 2) fly ash type and content (Class C/Class F, High/Low), 3) air-entraining admixture (3%/6%), and 4) coarse aggregate contents (High Stone Volume/Low Stone Volume). For each combination of factors, five specimens from each batch were prepared for the CTE measurements and thus, total number of specimens tested in this study was 320. To properly account for the effect of aggregate content changes on the CTEs, the slump was held to approximately 2-inch on all the concrete mixture designs by adjusting the amount of water used in the mixes. The results showed that concretes composed of high stone volume of granite with manufactured sand have the lowest CTE while those composed of low stone volume of dolomite with siliceous natural sand have the highest CTE value. It implies that the stone volume, aggregate type, and sand type significantly affect the CTE value. In this study, a multiple regression model was also developed to estimate the CTE as a function of coarse aggregate and sand types and contents. The prediction model was validated with field cored specimens, and overall R-square value of the prediction model was over 86%.
  Authors: Kim, Sung-Hee; Jeong, Jin-Hoon
  Authors: Kim, Sung-Hee; Jeong, Jin-Hoon
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 206
  Paper Number: 13-2727
  Practice-Ready: Yes
• Electrical Resistivity Measurements in Cementitious Systems: Observations of Factors That Influence the Measurements
  Abstract: The electrical resistivity of concrete is increasingly measured as an indicator of its fluid transport properties, for use in quality control or for service life prediction. While electrical tests have the advantage of being easy and rapid to perform, there are several key factors that can influence the results including: 1) specimen geometry, 2) specimen temperature and 3) sample storage and conditioning. This paper addresses these issues and compares the measurements from several commercially available testing devices. First, the role of sample geometry is explained using three common geometries: surface, uniaxial and embedded electrodes. If the geometry is properly accounted for, measurements from different test geometries result in electrical resistivity values that are similar. Second, the role of sample temperature is discussed for both pore solution and bulk tests on cylinders. Third, the paper examines the importance of sample curing, storage and conditioning. Sample storage and conditioning influences both the degree of hydration and the degree of saturation. The role of sample volume to solution volume is discussed as this may influence alkali leaching. This paper is intended to identify factors that influence the results of the rapid electrical test measurements and to help identify areas of future research that are needed so that robust specifications and standard test methods can be developed. This will enable electrical tests to be used to provide rapid, accurate, repeatable measurements of concrete’s electrical properties.
  Authors: Spragg, Robert; Villani, Chiara; Snyder, Kenneth; Bentz, Dale P.; Bullard, Jeffrey; Weiss, William Jason
  Authors: Spragg, Robert; Villani, Chiara; Snyder, Kenneth; Bentz, Dale P.; Bullard, Jeffrey; Weiss, William Jason
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 287
  Paper Number: 13-2857
  Practice-Ready: Yes
• Evaluation of Aggregate Imaging Techniques for Quantification of Morphological Characteristics
  Abstract: Aggregate morphological characteristics, including shape, angularity and surface texture, have a significant impact on the engineering properties of construction materials, such as hot-mix asphalt, and hydraulic cement concrete, etc. Consequently, quantification of morphological characteristics of aggregates are essential for quality control of both aggregate production and pavement construction. Imaging techniques provide a cost-effective means to conveniently measure the aggregate morphological characteristics without laborious work. However, these imaging techniques adopt various mathematical methods with different instrument setups, resulting in different definitions of morphological descriptors that are usually incomparable with each other. This paper evaluates prevalent image techniques used for aggregate morphological characteristics analysis, including equipment cost, repeatability and reliability, etc. Three imaging techniques, i.e., the second generation aggregate imaging measurement system (AIMS II), the first generation University of Illinois Aggregate Image Analyzer (UIAIA), and Fourier Transform Interferometer (FTI) system, are further evaluated by comparing the analysis results of seven types of aggregates of passing 3/4’’ sieve and retaining on 1/2’’ sieve in size with manual measurements and visual rankings. Analysis of variance between measurements using different methods is also conducted to evaluate the accuracy of each aggregate imaging system. Based on the data analysis, recommendations are made for the selection of appropriate imaging analysis techniques depending on which morphological characteristics engineers are most interested in.
  Authors: Wang, Linbing; Sun, Wenjuan; Tutumluer, Erol; Druta, Cristian
  Authors: Wang, Linbing; Sun, Wenjuan; Tutumluer, Erol; Druta, Cristian
  Year: 2013
  Document Type: Paper
  Subject: Geotechnology; Materials
  Session: 745
  Paper Number: 13-2955
  Practice-Ready: Yes
• Review of Precast Portland Cement Concrete Panel Technologies for Use in Expedient Portland Cement Concrete Airfield Pavement Repairs
  Abstract: Currently, there is a resurgent interest in the use of precast portland cement concrete (PCC) technologies for pavement construction and repairs. Precast PCC slabs using conventional materials have been utilized at irregular intervals for the last 50 or more years and can offer similar reductions in field installation time as cast in-place PCC with rapid strength gaining materials. This paper documents the history of precast pavement panels around the world for airfield and highway pavements for both repair and new construction work. This information will be used to assist in the development of a methodology for use in rapid full-depth airfield repairs ranging from temporary patches to permanent replacement slabs for rehabilitation. Specific challenges related to military airfield pavement repairs using precast PCC panels are also presented for optimization of a repair panel system for emergency airfield repairs.
  Authors: Priddy, Lucy Phillips; Bly, Peter Grant; Flintsch, Gerardo W.
  Authors: Priddy, Lucy Phillips; Bly, Peter Grant; Flintsch, Gerardo W.
  Year: 2013
  Document Type: Paper
  Subject: Construction; Materials; Pavements
  Session: 427
  Paper Number: 13-2956
  Practice-Ready: Yes
• Assessment of Warm-Mix Asphalt for Heavy-Traffic Airfields
  Abstract: This paper presents the results from testing warm mixed asphalt (WMA) mixtures designed for airfield pavements. The study was conducted in two phases. The first phase included laboratory tests on eleven WMA technologies. The tests in phase two were performed on three WMA mixtures and one hot mix asphalt (HMA) mixture produced in an asphalt plant. The evaluation included performance tests to assess WMA susceptibility to permanent deformation and moisture damage compared to HMA produced using the same aggregate blend. Test results indicate WMA is a potentially viable product for surface mixtures on airfield pavements. Although WMA exhibited poorer performance than HMA in moisture damage tests on laboratory-produced specimens, the plant-produced mix indicated very little difference compared to HMA. Rutting potential for WMA was somewhat greater than for HMA for mixtures produced both in the laboratory and in an asphalt plant according to asphalt pavement analyzer (APA) and Hamburg wheel tracking tests. Differences in performance among WMA mixtures were not attributed to a specific WMA technology category. Variations in performance test results between laboratory-produced specimens and plant-produced specimens were noted, indicating a need to require performance testing as part of a comprehensive quality assurance plan.
  Authors: Rushing, John F.; Mejias, Mariely; Doyle, Jesse D.
  Authors: Rushing, John F.; Mejias, Mariely; Doyle, Jesse D.
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 704
  Paper Number: 13-3017
  Practice-Ready: Yes
• Evaluation of Reclaimed Asphalt Pavement Materials from Ultrathin Bonded Bituminous Surface
  Abstract: Ultra-thin bonded bituminous surface (UBBS), also known as Novachip, is a preventive maintenance or thin surface treatment that consists of a thin, gap-graded hot-mix asphalt(HMA) layer applied over a thick polymer-modified emulsion. The Kansas Department of Transportation (KDOT) has been using UBBS since 2002. However, some of these projects are now being rehabilitated. The objective of this study is to evaluate whether reclaimed asphalt pavement (RAP) materials from existing UBBS layers can be used in chip seal and Superpave mixtures. UBBS millings were studied with two different polymer-modified emulsions to assess their performance as precoated aggregates in chipseal. The ASTM D7000-04 sweep test was used to assess chip retention of UBBS millings. Three different mix designs were developed for both 12.5-mm and 9.5-mm nominal maximum aggregate size (NMAS) Superpave mixtures using a PG 70-22 asphalt binder and three different percentages (0%, 10%, and 20%) of reclaimed UBBS materials. The designed Superpave mixes were then tested for performance in terms of rutting and stripping using the Hamburg wheel tracking device (HWTD) and moisture sensitivity by the modified Lottman tests. Sweep test results showed that UBBS millings did not improve chip retention. Superpave mix design data indicated volumetric properties of Superpave mixes with UBBS millings met all requirements specified by KDOT. HWTD and modified Lottman test results indicated all designed mixes performed better with the addition of UBBS millings as RAP materials.
  Authors: Musty, Haritha
  Authors: Musty, Haritha
  Year: 2013
  Document Type: Paper
  Subject: Geotechnology; Materials; Pavements
  Session: 285
  Paper Number: 13-3060
  Practice-Ready: Yes
• Use of Blast Furnace Slag as a Sustainable Material in Concrete Pavements
  Abstract: Slag materials are by-products of metallurgical processes that include metals production from ore and refinement of impure metals. They are residues from lime-based inorganic fluxes used in metal purification that solidify upon cooling. Slags are essentially waste materials that can be used in sustainable applications. Blast furnace slags and steel slags have been used for different pavement-related applications. In this paper, sustainability aspects of using air-cooled blast furnace slag (ACBFS) as a coarse aggregate in concrete pavements and considerations for its use in this application are presented.On the subject of sustainability, appropriate use of ACBFS rather than disposing of it as waste can significantly enhance sustainability by effectively contributing to all aspects of the “triple-bottom line,” resulting in economic, environmental, and social benefits as long as the performance of the concrete structure is not compromised through the use of ACBFS because any short-term economic and environmental gain will be rapidly eclipsed by the economic, environmental, and social costs of poor pavement performance. Thus, it is essential that engineers and contractors who use ACBFS aggregates in concrete understand its unique properties to make sure that the expected performance of the pavement over its design life will be achieved.Chemical and physical properties of ACBFS along with their effects on fresh and hardened concrete properties are discussed in the paper. Also discussed, are pavement design and construction considerations for using ACBFS as coarse aggregate in concrete for pavement applications.
  Authors: Jahangirnejad, Shervin; Van Dam, Thomas John; Morian, Dennis A.; Smith, Kurt D.; Perera, Rohan W.; Tyson, Samuel S.
  Authors: Jahangirnejad, Shervin; Van Dam, Thomas John; Morian, Dennis A.; Smith, Kurt D.; Perera, Rohan W.; Tyson, Samuel S.
  Year: 2013
  Document Type: Paper
  Subject: Geotechnology; Materials; Pavements
  Session: 284
  Paper Number: 13-3101
  Practice-Ready: Yes
• Impact of Modulus-Based Device Variability on Quality Control of Compacted Geomaterials Using Measurement System Analysis
  Abstract: The advances in technology have resulted in new generation of in-situ nondestructive testing devices that can estimate stiffness parameters of compacted geomaterials. These include the light weight deflectometers , portable impulse plate load test devices, electro-mechanical stiffness devices and seismic devices. Despite a number of formal research and pilot studies, only a few agencies are attempting to implement these devices in their acceptance specifications. One of the main concerns is with the large variability in the stiffness parameters obtained with these devices when compared to densities measured with traditional devices (e.g. nuclear density gauge). The sources of the variability can be material-related, operator-related or device-related. It would be beneficial to systematically delineate the contributions of these sources of variability so that the equipment developer can improve their devices, highway agencies can modify their testing protocols, and pavement geotechnical engineers can address the material-related issues. This paper contains the results of an effort to quantify the equipment- and operator-related variability in a systematic manner. Measurement system analysis principles were applied to a database of stiffness measurements made with four stiffness-measuring devices on eighteen separate specimens that were prepared from the same material at similar densities and moisture contents. It was found that most devices are reasonably repeatable and reproducible as long as the moisture content and density are rigidly controlled. Most of the site specific variability reported in the literature may be due to lack of rigid process control during construction.
  Authors: Mazari, Mehran; Garcia, Gerardo; Garibay, Jose; Abdallah, Imad N.; Nazarian, Soheil
  Authors: Mazari, Mehran; Garcia, Gerardo; Garibay, Jose; Abdallah, Imad N.; Nazarian, Soheil
  Year: 2013
  Document Type: Paper
  Subject: Geotechnology; Materials
  Session: 291
  Paper Number: 13-3192
  Practice-Ready: Yes
• Investigation of Factors Affecting Surface Resistivity Through Ruggedness Testing
  Abstract: Many entities currently use permeability specifications in portland cement concrete (PCC) pavements and structures. Recent studies have shown surface resistivity testing correlates well with rapid chloride penetration (RCP) testing. The success of this research has led to surface resistivity testing on portland cement concrete cylinders being implemented in Louisiana. However, many of the studies have questioned the impact of various factors on surface resistivity measurements. This project investigates a ruggedness factorial using many of the factors in question to determine the level of impact of each factor. A partial factorial consisting of 35 combinations of factors was developed using eleven factors and sixteen mixtures. Some factors were mixture dependent, so RCP testing was also performed on a portion of the factorial to determine if factors influence the surface resistivity meter or permeability in general. The ruggedness study showed age and aggregate type as significant factors for surface resistivity. Additional comparisons against a control suggested age, calcium nitrite, aggregate size, and aggregate type as significant factors for surface resistivity. However, comparative RCP testing on the same sample sets concluded that all significant factors determined either affect the permeability of the sample in general or will influence rapid chloride permeability as well.
  Authors: Icenogle, Patrick; Rupnow, Tyson; Johnson, Katelyn
  Authors: Icenogle, Patrick; Rupnow, Tyson; Johnson, Katelyn
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 206
  Paper Number: 13-0727
  Practice-Ready: Yes
• Design and Constructability of Emulsion-Stabilized Bases forFull-Depth Reclamation
  Abstract: Full-depth reclamation (FDR) of base courses with calcium-based stabilizers has been a common practice in many areas of Texas. Owing to its speed of operation and minimal lane closure period, asphalt emulsion has been recently used in a number of FDR projects in low volume roads as well. A few cases of premature failure of these stabilized bases primarily due to improper (or lack of) mix design or construction techniques led to a thorough evaluation and recommendations for an improved mix design and construction specification. The outcomes of a thorough evaluation of construction-related, material-related and environmental-related parameters that significantly impact the performance of emulsion-treated base materials were used to propose laboratory test procedures for mix design and guidelines for the construction of bases with emulsion. The practical aspects of this study that are incorporated in a trial specification are discussed in this paper.
  Authors: Nazarian, Soheil; Yuan, Deren
  Authors: Nazarian, Soheil; Yuan, Deren
  Year: 2013
  Document Type: Paper
  Subject: Geotechnology; Materials; Pavements
  Session: 740
  Paper Number: 13-2256
  Practice-Ready: Yes
• Durability Assessment of Coarse Aggregates for Hot-Mix Asphalt in Maine
  Abstract: In this study, Micro-Deval and L.A. Abrasion were used to evaluate the durability of 72 individual coarse aggregates used for HMA in Maine. Aggregates used in hot-mix asphalt (HMA) must be durable and resistant to abrasion and degradation. Material loss in HMA pavements has recently been observed by MDOT and aggregate degradation has been hypothesized as a possible contributor. The Micro-Deval results showed no correlation with results from the L.A. Abrasion and the range in values was quite large. Two alternative methods of analyzing Micro-Deval were employed to measure the change in gradation of aggregate samples. A relatively large portion of tested aggregate sources were found to degrade significantly in the Micro-Deval test while having acceptable AASHTO Micro-Deval loss values, this presumably due to fracturing instead of abrasion. The weighted average method and area between curves method proved to be effective in measuring the change in particle size distribution not captured with the Method 1 Micro-Deval loss value. In addition, a significant influence of initial grading size was found in all of the Micro-Deval data with finer initial gradations producing higher loss values. The alternative analysis methods for Micro-Deval are recommended for use in detecting degradation not captured by the traditional Micro-Deval value.
  Authors: Nener-Plante, Derek
  Authors: Nener-Plante, Derek
  Year: 2013
  Document Type: Paper
  Subject: Geotechnology; Materials; Pavements
  Session: 285
  Paper Number: 13-2713
  Practice-Ready: Yes
• Investigating the Potential to Alleviate the Expansive Nature of Steel Slag Aggregate in Portland Cement Concrete
  Abstract: Sustainability in the built environment is of increasing importance, particularly in the transportation sector. Slags from the iron and steel industries can be used in some cases to replace natural aggregates in construction. State DOT’s do not permit the use of steel slag, a by-product of the production of steel, as an aggregate in portland cement concrete (PCC). However, that potential exists provided the expansive nature of untreated steel slag can be alleviated. In this study, a review of world-wide research and case studies was undertaken. Although a few case studies and limited field applications were found, the vast majority of the research has been in the laboratory. Much of this work has shown that steel slag can be treated to be non-expansive and acceptable for use in PCC. It should be noted that when evaluating these research results, it is important to carefully consider the properties of the slags used, which may differ significantly from slags produced in the U.S. due to differences in sources or industrial processes. While the various treatment processes discussed have shown various degrees of success in reducing the expansive nature of steel slag, there is variability in the properties of steel slag, current treatment processes are not uniformly adopted, testing has not been performed on a large enough scale, and the processes do not reduce all risk of volume instability. Hence, more study is needed, and therefore at this time the use of steel slag in rigid pavement applications is not recommended.
  Authors: Fronek, Brad; Bosela, Paul A.; Delatte, Norbert Joseph
  Authors: Fronek, Brad; Bosela, Paul A.; Delatte, Norbert Joseph
  Year: 2013
  Document Type: Paper
  Subject: Geotechnology; Materials; Pavements
  Session: 284
  Paper Number: 13-2869
  Practice-Ready: Yes
• Development of Fog Seal Field Test Methods and Performance Evaluation Using Polymer-Modified Emulsions
  Abstract: One of the most cost-effective pavement preservation treatments used in North Carolina is the bituminous surface treatment, or so-called chip seal. However, the major concern with chip seals is aggregate loss. Fog seals can be used to prevent or at least reduce the occurrence of aggregate loss in chip seals and extend the service life of the pavement. Other benefits of fog seal are low cost, ease of construction, and a desirable black appearance, to name a few. A few disadvantages of fog seals, such as delay in opening to traffic and reduction in skid resistance, also have been reported. In order to achieve a satisfactory fog seal performance, it is necessary to understand the fog seal emulsion properties (e.g., curing time and adhesive behavior). In this study, polymer-modified emulsions (PMEs) are compared to unmodified emulsions as fog seal materials. The study shows that polymer modification can improve certain properties of emulsions, such as an increase in adhesion. The evaporation test and the pneumatic adhesion tension testing instrument (PATTI) test are used to investigate the emulsion curing and adhesive behavior. Also, the rolling ball test and the damping test have been developed as in situ test methods to determine an appropriate traffic opening time for roadways treated with fog seals. Finally, the third-scale model mobile load simulator (MMLS3) is employed to compare the performance properties of the fog seal emulsions. The main findings presented in this paper are that: (1) the use of PMEs improves the emulsion bond strength and lessens the time a road is closed to traffic; (2) PMEs show more effective emulsion curing rates than unmodified emulsions; (3) strong relationships exist between the bond strength and both the rolling distance and the percentage of stained area that are measured from the rolling ball test and damping test, respectively; (4) the field test methods can be used to help determine whether emulsions are fully cured or not; and (5) PMEs exhibit better aggregate retention and bleeding performance properties than unmodified emulsions as a fog seal.Keywords: pavement preservation treatments, fog seal, polymer-modified emulsions (PMEs), curing time, adhesive behavior, field test methods
  Authors: Im, Jeong Hyuk; Kim, Y. Richard
  Authors: Im, Jeong Hyuk; Kim, Y. Richard
  Year: 2013
  Document Type: Paper
  Subject: Maintenance and Preservation; Materials; Pavements
  Session: 654
  Paper Number: 13-2996
  Practice-Ready: Yes
• Improving the Properties of Reclaimed Asphalt Pavement for Roadway Base Applications Through Blending and Chemical Stabilization
  Abstract: Finding innovative ways to incorporate Reclaimed Asphalt Pavement (RAP) into highway base course applications will provide both environmental and economic benefits by allowing in situ recycling of material for projects such as widening or shoulder addition. RAP is a well-drained granular material, however 100% RAP has low bearing strength and creeps under load. The objective of this research was to develop methods to improve RAP’s strength while reducing creep to an acceptable level through blending with high quality crushed limestone aggregate and/or by chemical stabilization with asphalt emulsion or Portland cement. RAP/aggregate blends with and without chemical stabilization were compacted by modified Proctor method, cured, and tested for strength and creep. Strength was tested by the limerock bearing ratio (LBR), a variant of the CBR test. Specimens were tested dry and soaked to evaluate retained strength. One dimensional creep testing was performed using seven day oedometer tests. RAP/aggregate blends have the potential to be used successfully as base course material. Blends of RAP with 50% limerock (LR) base material attained acceptable LBR strength and creep with the addition of 1% of either asphalt emulsion or cement. Blends of RAP with 75% or more limerock attained close to acceptable LBR and low levels of creep without any chemical stabilizer. Significant variability was noted between results with different blends and stabilizing agents. Performance testing should be conducted to establish the suitability of a specific RAP/aggregate blend.
  Authors: Bleakley, Albert M.; Cosentino, Paul J.
  Authors: Bleakley, Albert M.; Cosentino, Paul J.
  Year: 2013
  Document Type: Paper
  Subject: Geotechnology; Materials; Pavements
  Session: 285
  Paper Number: 13-2062
  Practice-Ready: Yes
• Aggregate Size and Shape Evaluation using Segmentation Techniques and Aggregate Image Processing Algorithms
  Abstract: Morphological properties of mineral aggregates are known to affect pavement and railroad track mechanistic behavior and performance significantly in terms of strength, modulus and permanent deformation. With imaging technology, an objective and accurate measurement of aggregate particle size and shape properties can be obtained in a rapid, reliable and automated fashion. Yet, there is a need to bring these advances in aggregate imaging to project sites and quarries in the field. This paper introduces field image acquisition and processing techniques for extraction and analyses of individual aggregate particle size and shape properties. Referred to as segmentation techniques, image processing methods developed in this study analyzed 2-D field images of aggregates captured by a Digital Single Lens Reflex (DSLR) camera. The segmented aggregate images were fed into the validated University of Illinois Aggregate Image Analyzer (UIAIA) to quantify particle size and shape properties by means of its image processing algorithms for Flat and Elongated Ratio (FER), Angularity Index (AI), and Surface Texture Index (STI). The developed method successfully determined the properties of coarse aggregate samples collected from various depths in a railroad track ballast layer. The promising preliminary results indicate that these segmentation techniques can be considered in the field to capture several aggregate particles rapidly and reliably in a single image so that individual particle size and shape properties can be analyzed and further, both spatial property variability and property changes with layer depth and usage, i.e., property degradation in time, can be evaluated under service loading.
  Authors: Moaveni, Maziar; Wang, Shengnan; Hart, John M.; Tutumluer, Erol; Ahuja, Narendra
  Authors: Moaveni, Maziar; Wang, Shengnan; Hart, John M.; Tutumluer, Erol; Ahuja, Narendra
  Year: 2013
  Document Type: Paper
  Subject: Geotechnology; Materials
  Session: 745
  Paper Number: 13-4167
  Practice-Ready: Yes
• Analysis of Texas Superheavy Load Criteria for Bridges
  Abstract: The number of permits for superheavy loads crossing Texas bridges has steadily increased over the years, and, compared with several other states, the criteria that establish superheavy-load status is generous. The result is that many Texas bridges experience routine, high-stress loads that cause accelerated deterioration. In this study, bridge load and rating factors and the validity of the criteria for establishing superheavy load status are evaluated. The primary objective of this study was to evaluate Texas Superheavy load criteria for bridges. To accomplish this, field tests for the response behavior of a bridge subjected to overweight vehicles and parametric study using finite element analysis were utilized to extract bridge criteria triggers. The field calibrated solid model and related parametric study show that the Texas superheavy load criteria are valid for the study bridge type. Bridge rating, using the distribution factors determined in the study, show that the bridge has much reserve capacity, even with short 230 kip and longer 311 kip superheavy loads applied. The parametric study using finite element modeling shows that the criteria adequately protect this bridge type. Because the criteria are based on TxDOT’s prior permitting, a graphical version of the criteria might serve TxDOT and carriers better than does the gross vehicle weight limits alone. Data collected long term of frequency and load level from a relevant bridge would help TxDOT determine what effects stress level variations have on the life of Texas bridges.
  Authors: Chang, Byungik; Bourland, Mark Cleve; Couch, Todd; Zou, Hao
  Authors: Chang, Byungik; Bourland, Mark Cleve; Couch, Todd; Zou, Hao
  Year: 2013
  Document Type: Paper
  Subject: Bridges and Other Structures; Maintenance and Preservation; Materials
  Session: 401
  Paper Number: 13-4119
  Practice-Ready: Yes
• Performance of Various Pavement Repairs in Low-Volume Roadways over Expansive Soil
  Abstract: Expansive soil is considered one of the most common causes of pavement distresses. Depending upon the moisture level, expansive soils will experience changes in volume due to moisture fluctuations from seasonal variations. The objective of this research was to evaluate existing repair projects on selected roadways. Those roadways experienced failures in the form of fatigue and rutting in the wheel path, and longitudinal (faulted) cracking including edge cracking. The causes of those failures were mainly linked to high plasticity expansive soil and narrow pavement. The study involved visual survey, field and laboratory testing, surface condition/ride data and structural design calculations for three project sites. The study concluded, from 3-14 years of performance records, that geogrid reinforcement, lime-treated subgrade and cement-treated base were found to be effective treatment options for low-volume roadways where high plasticity expansive soil exists.
  Authors: Dessouky, Samer H; Oh, Jeong Ho; Bourland, Mark Cleve; Ilias, Mohammad; Lee, Sang Ick; Park, Dae-Wook
  Authors: Dessouky, Samer H; Oh, Jeong Ho; Bourland, Mark Cleve; Ilias, Mohammad; Lee, Sang Ick; Park, Dae-Wook
  Year: 2013
  Document Type: Paper
  Subject: Maintenance and Preservation; Materials; Pavements
  Session: 808
  Paper Number: 13-4208
  Practice-Ready: Yes
• Analytical and Laser Scanning Techniques to Determine Shape Properties of Mineral Aggregates
  Abstract: The fundamental shape attributes of aggregates used in pavements i.e., form, angularity, and surface texture have not been accurately quantified historically, because of their irregular and non-ideal shapes. This paper presents selected results using a laser-based scanning technique to determine the form of aggregates used in construction of pavements in South Africa. A three-dimensional (3-D) laser scanning system was used to scan aggregate materials from different sources, and the data were processed to reconstruct 3-D models of the aggregate particles. The models were further analyzed to determine the form properties. In this paper, two analysis approaches, based on aggregate physical properties and spherical harmonic analysis, were employed to determine the aggregate form indices. The aggregate form indices obtained from the physical aggregate properties were compared with the form indices computed based on the spherical harmonic analysis. The indices based on the physical properties include sphericity computed from the surface area and volume, sphericity computed from three orthogonal dimensions, and flat and elongated ratio computed from the longest and shortest dimensions of an aggregate particle. Good correlations were observed between the form indices obtained from the aggregate physical properties, and the spherical harmonic form index. It is concluded that laser scanning technique could be employed to better quantify the form properties of aggregate materials used in pavements.
  Authors: Anochie-Boateng, Joseph; Komba, Julius; Steyn, Wynand Jacobus van der Merwe
  Authors: Anochie-Boateng, Joseph; Komba, Julius; Steyn, Wynand Jacobus van der Merwe
  Year: 2013
  Document Type: Paper
  Subject: Geotechnology; Materials
  Session: 745
  Paper Number: 13-4454
  Practice-Ready: Yes
• Performance Characterization of High Binder Replacement with Recycled Asphalt Shingles for Low N-design Mixture
  Abstract: ABSTRACTRecycled materials can be used effectively in asphalt mixtures to replace virgin asphalt binder or virgin aggregates. Virgin material (asphalt binder or aggregate) can be replaced utilizing reclaimed asphalt pavement (RAP) and recycled asphalt shingles (RAS) in asphalt mixtures. In this paper, the effect of high asphalt binder replacement for a low N-design asphalt mixture including RAP and RAS on performance indicators such as permanent deformation, fracture, and fatigue potentials, and stiffness, was studied. A developed experimental program included complex modulus, fracture, overlay reflective cracking resistance, wheel track permanent deformations, and push-pull fatigue tests. The asphalt binder replacement, combinations of RAS and RAP asphalt binder, levels in the mix were in a range of 43 to 64%. Permanent deformation resistance of the mixtures was improved in the presence of RAS. Fracture tests at low temperature did not reveal any significant difference between the specimens prepared at varying percentages of asphalt binder replacement. Fatigue potential of mixtures increased with increasing RAS content and asphalt binder replacement. The specimens prepared with 2.5% RAS and PG 46-34 showed the best fatigue performance. The impact of asphalt binder bumping was highlighted by the results of all tests. The improvement in fatigue life and fracture energy was noticeable when the asphalt binder type was changed from PG 58-28 to PG 46-34 at the highest asphalt binder replacement level. The results showed that complex modulus test results can provide crucial information about the mix viscoelastic properties such as relaxation potential and long-term stiffness that can be used, along with fracture tests, to evaluate mix brittleness at relatively high asphalt binder replacement levels.
  Authors: Ozer, Hasan; Al-Qadi, Imad L.; Kanaan, Ahmad; Lippert, David Leslie
  Authors: Ozer, Hasan; Al-Qadi, Imad L.; Kanaan, Ahmad; Lippert, David Leslie
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 656
  Paper Number: 13-4500
  Practice-Ready: Yes
• Effect of Accelerated Curing on Surface Resistivity and Rapid Chloride Permeability of High-Performance Concrete
  Abstract: Recently, many bridges were built using High Performance Concrete (HPC) to increase their durability. However, when subjected to cracking or exposed to aggressive environments, their durability would gradually diminish, causing corrosion of reinforcement in the deck. This phenomenon is one of the major factors causing delamination and structural deficiencies of concrete decks. The corrosion risk is directly related to the chloride ion permeability of the concrete, which can be determined using permeability testing at a minimum of 56 days. Since the permeability testing is time consuming and labor–intensive, many of State Department of Transportations (DOT’s) are exploring the use of more expedient and less variable testing methods. To evaluate the long-term durability aspects of HPC at an earlier acceptance age but with lower cost, accelerated curing and concrete resistivity measurement are proposed as a potential replacement. There is a need to understand the effect of accelerated curing on concrete resistivity and chloride ion permeability as a measure of durability.This paper conducts an experimental program to evaluate the effects of accelerated curing on durability performance of HPC. Both the Surface Resistivity (SR) and the Rapid Chloride Permeability (RCP) tests were performed on concrete cylinders cured under accelerated as well as normal wet curing conditions. Results show that RCP testing can be substituted by SR testing as a measure of the durability of concrete. Moreover, accelerated curing can expedite the time needed to test permeability. Additionally, SR testing combined with accelerated curing correlated well with results from RCP testing.
  Authors: Salvador, Michael; Na, Chaekuk; Nassif, Hani; Corso, Frank
  Authors: Salvador, Michael; Na, Chaekuk; Nassif, Hani; Corso, Frank
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 287
  Paper Number: 13-4676
  Practice-Ready: Yes
• Field and Laboratory Evaluation of Winter Season Pavement Patching Materials in Tennessee
  Abstract: Field survey and laboratory tests were conducted to evaluate the performance of four patching materials used in winter season pothole repair in Tennessee. The adhesiveness, cohesion, moisture susceptibility and loaded wheel test were conducted to investigate the bonding, freeze-thaw resistance and rutting resistance of the patching materials. Statistical analysis on the six month field survey showed that edge disintegration and missing patch are the mainly distress of “throw and roll” patching in winter season. Severe freeze condition, high traffic level and vehicle speed accelerated the deterioration of patching. Patchings with lower depth and larger size especially longer longitudinal length deteriorated faster. Both field and adhesiveness test showed that the cold dump mix had high potential to edge disintegration and missing patch, which is probably caused by the insufficient binder content or an excessive stiff binder. One cold bag mix showed high potential to deformation and low strength performance, mainly due to its single size gradation and weak aggregate skeleton. Cohesion test conducted at different temperature and compaction times presented consistent ranking of materials. 25°C and 15 blows were recommended to evaluate the cohesion of materials at moderate temperature. Two cold mixes did not withstand the 60°C water bath in the freeze-thaw cycling due to the high air voids and 25°C was suggested instead. Reduced wheel load is recommended to improve the effectiveness of loaded wheel test for cold patching mixtures.
  Authors: Dong, Qiao; Huang, Baoshan; Shu, Xiang
  Authors: Dong, Qiao; Huang, Baoshan; Shu, Xiang
  Year: 2013
  Document Type: Paper
  Subject: Maintenance and Preservation; Materials; Pavements
  Session: 808
  Paper Number: 13-4772
  Practice-Ready: Yes
• Linking Small and Large Strain Behavior of Soils Using Shear Wave Velocity Measurements in the Laboratory
  Abstract: Current geotechnical practice relies on empirical relationships with in situ tests to determine the effective stress strength parameters for dense cohesionless soils. Although these methods work reasonably well in practice, they cannot account for in situ effects related to time, fabric, and cementation. These factors are especially important for brittle or sensitive soils, such as loess and cemented sands. To develop methods that can predict strength in these types of soils, a better understanding of the link between small and large strain behavior is needed. The objective of this paper is to evaluate the hypothesis that there is a unique relationship between the small strain shear modulus (G0) and the effective stresses at failure (s'1f) for dilatant soils. To accomplish this objective, isotropically consolidated-drained triaxial compressional tests were performed with shear wave velocity measured throughout the tests. The soils tested in this study include a quartz sand and non-plastic silt, and the results are compared to previous studies by the authors on weakly cemented sands.It was found that the ratio G0/s'1f was approximately 197 ± 16 for the three different soils tested, and was independent of density, degree of cementation, and confining stress. If true for other soils, this finding could have important implications for evaluating staged construction on sensitive soils and estimating the strength of dilative soils in situ.
  Authors: Guadalupe, Yaurel; Baxter, Christopher; Sharma, Ravi
  Authors: Guadalupe, Yaurel; Baxter, Christopher; Sharma, Ravi
  Year: 2013
  Document Type: Paper
  Subject: Geotechnology; Materials
  Session: 291
  Paper Number: 13-4893
  Practice-Ready: Yes
• Soil Stiffness Assessment of Stabilized Pavement Foundations
  Abstract: The quality of constructed pavement foundation layers was studied using rapid and near-continuous soil stiffness measurements as alternatives to traditional nuclear gauge moisture/density measurements. Sixteen different stabilized pavement foundation sections covering 4.8 miles were studied with ground conditions ranging from soft to very stiff. Measurements from falling weight deflectometer, light weight deflectometer, and roller-integrated compaction monitoring systems were used to assess soil stiffness. Statistical analyses of the results are reported in the form of coefficient of variation and empirical correlations between measurements. Results of soil stiffness were compared to two independent groups of nuclear moisture/density measurements to demonstrate some of the shortcomings of traditional nuclear gauge testing for quality assessment. The findings from this paper show the value in characterizing ground variations using soil stiffness measurements. Cost data is also reported for the stabilized sections. (135 words)
  Authors: White, David J.; Becker, Peter; Vennapusa, Pavana Kumar Reddy; Dunn, Mark; White, Christianna
  Authors: White, David J.; Becker, Peter; Vennapusa, Pavana Kumar Reddy; Dunn, Mark; White, Christianna
  Year: 2013
  Document Type: Paper
  Subject: Geotechnology; Materials; Pavements
  Session: 564
  Paper Number: 13-5073
  Practice-Ready: Yes
• Development of Optimum Fractionation Method for High-RAP Mixturesby Sieve-by-Sieve Analysis of RAP Materials
  Abstract: The main objective of this research is to examine the effects that different methods of RAP stockpile fractionation have on the volumetric mix design properties for high-RAP content surface mixes, with the goal of meeting all specified criteria for standard HMA mix designs. To determine the distribution of fine aggregates and binder in RAP stockpile, RAP materials were divided by each sieve size. The composition of RAP materials retained on each sieve was analyzed to determine the optimum fractionation method. Fractionation methods were designed to separate the stockpile at a specified sieve size to control the amount of fine RAP materials which contain higher amounts of fine aggregates and dust contents. These fine RAP materials were used in reduced proportions or completely eliminated, thereby decreasing the amount of fine aggregate materials introduced to the mix. Mix designs were performed using RAP materials from three different stockpiles and the two fractionated methods were used with high-RAP contents up to 40% by virgin binder replacement. By using an optimum fractionation method, a mix with 40% RAP was successfully designed while meeting all Superpave criteria and asphalt film thickness requirement by controlling the dust content from RAP stockpiles.
  Authors: Shannon, Cory; Lee, Hosin; Tang, Sheng; Williams, Ronald Christopher; Schram, Scott Alan
  Authors: Shannon, Cory; Lee, Hosin; Tang, Sheng; Williams, Ronald Christopher; Schram, Scott Alan
  Year: 2013
  Document Type: Paper
  Subject: Geotechnology; Materials; Pavements
  Session: 285
  Paper Number: 13-5098
  Practice-Ready: Yes
• Observed Variability in Tests of Fresh Concrete Propertiesfrom NHI Highway Materials Engineering Course
  Abstract: From 1990 to 2008 an integral component of the PCC module of the annual NHI Highway Materials Short Course was a series of independent and parallel evaluations of fresh and hardened properties for a single load of concrete. Up to six testing teams independently sampled concrete from the truck and tested the fresh concrete for temperature, slump, and air content by pressure and by volume meter. The experiment was repeated annually to demonstrate test procedures and the variability in test results for concrete from a single load. Results indicate the time-dependency in both slump and apparent air content, the relationship between slump and apparent air content, and the difference between air content as indicated by the AASHTO T152/ASTM C231 pressure air meter and the AASHTO T196/ASTM C173 volumetric air meter
  Authors: Hover, Kenneth Clark
  Authors: Hover, Kenneth Clark
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 206
  Paper Number: 13-5257
  Practice-Ready: Yes
• Economic Evaluation of Commercial Remote Sensors for Bridge Health Monitoring
  Abstract: The Michigan Tech Transportation Institute (MTTI) and Michigan Tech Research Institute (MTRI), in cooperation with the Center for Automotive Research (CAR) and the Michigan Department of Transportation (MDOT), have completed research that investigates the use of remote sensing technologies to assess and monitor the condition of bridge infrastructure. This study was funded largely by the USDOT Research and Innovative Technology Administration as part of an effort to improve the efficiency and cost-effectiveness of bridge inspection, repair, and rehabilitation efforts. Remote sensing technologies were correlated with in-place sensors and traditional inspection methods to obtain bridge condition assessment data and evaluate them as part of an integrated decision support environment to move them toward practical use in structural health monitoring. As part of the overall effort, CAR researchers conducted an evaluation of the cost-effectiveness of a broad deployment of remote sensing techniques for bridge condition assessment and a decision support system (DSS) for bridge infrastructure management. After background research, laboratory testing, field demonstration, and interviews with bridge inspection experts, three technologies emerged as having the most potential for cost-effective implementation: 3D Optical Bridge Evaluation System (3DOBS), Thermal Infrared Imagery (ThIR), and Ultra Wide Band Imaging RADAR System (UWBIRS). The researchers conclude that investment in remote sensing technologies for bridge health monitoring can enhance technical performance of bridge inspection and improve the resource allocation decision process for transportation agencies. Use of these technologies can be especially beneficial when combined with a decision support system (DSS), such as that developed by the research team.
  Authors: Hong, Qiang; Wallace, Richard; Ahlborn, Theresa M.; Brooks, Colin Neil; Dennis, Eric Paul; Forster, Mike
  Authors: Hong, Qiang; Wallace, Richard; Ahlborn, Theresa M.; Brooks, Colin Neil; Dennis, Eric Paul; Forster, Mike
  Year: 2013
  Document Type: Paper
  Subject: Bridges and Other Structures; Maintenance and Preservation; Materials
  Session: 401
  Paper Number: 13-3978
  Practice-Ready: Yes
• Scour Assessment of Bridge Foundation Using In Situ Erosion Evaluation Probe
  Abstract: AbstractWork in this paper presents the use of the In Situ Erosion Evaluation Probe (ISEEP) for the assessment of scour depth a bridge pier. Numerical modeling and deployment of the device at a North Carolina Barrier Islands site after Hurricane Irene in 2011 demonstrated the applicability of the proposed concept. The CFD software Flow 3D was used to evaluate scour at bridge piers with the scour depth also estimated based on ISEEP data using excess stream power. The scour depth was also computed using empirical equations assuming the same conditions used in the numerical analysis. The parametric analyses indicated that among the parameters commonly used for defining the scour depth, entrainment coefficient (Ce) has the largest effect, whereas drag coefficient (Cd) has the smallest effect on the estimated scour depth. Scour depth estimated based on ISEEP data agreed relatively well with values obtained from the numerical analyses, as the data reflected the change in the properties of the sand layer with depth. On the other hand, the scour depth estimates from empirical equations were unconservative mainly due to not accounting for the two-layered profile. The use of ISEEP data provides the advantage of in situ assessment of scour parameters as the properties of the soil layers vary with depth. Further validation of the device and data reduction approach is however needed including its applicability in soils with fine contents.
  Authors: Kayser, Mohammad; Gabr, Mohammed A.
  Authors: Kayser, Mohammad; Gabr, Mohammed A.
  Year: 2013
  Document Type: Paper
  Subject: Geotechnology; Materials
  Session: 291
  Paper Number: 13-4010
  Practice-Ready: Yes
• Forensic Study on Cracking Distress of New Jersey’s LTPP SPS-5 Sections: 30% RAP Versus Virgin Hot-Mix Asphalt
  Abstract: In 2010, New Jersey’s Long Term Pavement Performance (LTPP) SPS-5 sections closed out. Prior to the rehabilitation of these pavement sections, an extensive coring and forensic study was conducted to characterize the material properties of the Virgin and 30% RAP asphalt mixtures utilized on the project. Along with field cores, raw materials (i.e. – aggregates, binder, loose mix) was procured from FHWA-LTPP Materials Reference Library. Visual distress surveys from the LTPP database were collected and utilized to compare the mixture performance to the general field performance. Overall, the field performance indicated that both the virgin and 30% RAP sections initiated cracking within 1 to 3 years of each other, depending on the section evaluated. However, once cracking had been initiated, the 30% RAP sections cracked at a faster rate than the Virgin sections resulting in higher crack counts, even though the 30% RAP section was using a softer binder than the virgin section (i.e. – AC-10 vs AC-20). The Overlay Tester, Disk Shaped Compact Tension (DC(T)), and Low Temperature IDT and Creep Compliance were used to characterize intermediate and low temperature cracking properties of the mixtures. Asphalt binder characterization included PG grading, master stiffness curves, and Linear Amplitude Sweep (LAS) testing to characterize the stiffness and fatigue properties of the asphalt binders. The material testing program showed that the mixture test results matched the observed field cracking performance better than the asphalt binder testing conducted on the extracted and recovered asphalt binders. The Overlay Tester and DC(T) tests appeared to be the most sensitive to the cracking performance differences between the Virgin and 30% RAP mixtures, while the LAS test appeared to rank the fatigue performance of the 30% RAP mixture better than the Virgin mixture, which contradicted the observed field performance.
  Authors: Bennert, Thomas A.; Maher, Ali
  Authors: Bennert, Thomas A.; Maher, Ali
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 656
  Paper Number: 13-4289
  Practice-Ready: Yes
• Potential Issues with Generation and Stability of Air-Void System due to Incompatibility of Components in Plain and Fly Ash Cementitious Mixtures
  Abstract: Continuing desire to create more sustainable and durable infrastructure leads to the increased usage of various mineral and chemical admixtures as components of present-day concrete mixtures. Unexpected incompatibility problems may arise in certain mixtures as a result of complex interactions that frequently take place between these components. This paper presents an investigation on identifying combinations of component materials which can result in problems related to generation and stability of air-void system (AVS) in both plain and fly ash mixtures.A low (0.3%) alkali Type I cement, a class F fly ash and four chemical admixtures were used in this study. Two out of these four admixtures included different types of air entraining agents (AEA): a) vinsol resin based air entraining agent and b) synthetic type air entraining agent. The other two admixtures included the lignin based Type A water reducing agent (WRA) and polycarboxylate type superplasticizer. In addition to plain cementitious mixtures prepared from various combinations of these components, fly ash mixtures (with 20 and 60% weight replacement of cement by Class F fly) were also studied. The potential degree of difficulty in generating air-voids in fresh concrete was evaluated using the foam index tests (performed on paste slurries) and by measuring the air content of mortar mixtures (performed according to the AASHTO T137). Stability of air-void system in concretes was evaluated using the foam drainage test (performed on paste slurries).The results showed that the amount of the AEA required to obtain the target air percentage increased with the increase in the fly ash content in the mixture. The lignin based WRA had, in general, a higher air entraining effect than the super-plasticizer when used in combination with air entrainers. In general mixtures prepared with synthetic air entraining agent exhibited more stable foam system than mixtures prepared with vinsol resin based air entraining agent.
  Authors: Paleti, Chaitanya
  Authors: Paleti, Chaitanya
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 287
  Paper Number: 13-4537
  Practice-Ready: Yes
• Estimation of Subgrade Resilient Modulus Using Unconfined Compression Test
  Abstract: Resilient modulus test is the recommended test to characterize subgrade soil for pavement design in 1993 AASHTO pavement design guide as well as new proposed Mechanistic-Empirical Pavement Design Guide (MEPDG). This test requires significant resources including high level of technical capability to conduct. For smaller projects where costly and complex resilient modulus testing is not justified, correlation with other simpler tests could be used. Virginia Department of Transportation uses a simple correlation with California Bearing Ratio (CBR) to estimate resilient modulus for their current AASHTO design. As the correlation with CBR was found to be poor, a simpler unconfined compression test is explored for a better estimation of resilient modulus of fine grained soils. A model is proposed to estimate the resilient modulus of fine grained soil from the results of unconfined compression test.
  Authors: Hossain, Shabbir; Kim, Wan Soo
  Authors: Hossain, Shabbir; Kim, Wan Soo
  Year: 2013
  Document Type: Paper
  Subject: Geotechnology; Materials; Pavements
  Session: 564
  Paper Number: 13-4564
  Practice-Ready: Yes
• Moisture Damage Evaluation of Asphalt Mixes containing Mining By-products (Taconite Tailings) using Traditional and Fracture Energy Tests
  Abstract: The availability of mineral aggregates for pavement construction is continuously depleting. The aggregate manufacturing process requires significant amount of energy ranging from 10-30 MJ/ton. The process also produces 5 kg/ton of CO2 causing significant amounts of greenhouse gas emissions. With annual consumption of approximately 1.2 billion tons of aggregates in the United States, significant environmental impact is caused. Annually more than 125 million tons of fine grained crushed siliceous material is generated through iron ore mining in Northern Minnesota. This material is typically referred to as “taconite tailings” and usually ends up as landfills near mining operations.This paper describes moisture damage evaluation of asphalt mixes containing significant fraction of aggregate as taconite tailings. The evaluation is conducted using conventional AASHTO T-283 test procedure as well as fracture energy based approach. The paper presents comparative results for two mixes, one made with taconite tailings and other one using conventional granite aggregates. The results indicate that mix containing taconite has acceptable moisture damage resistance. The results also point out the limitations of AASHTO T-283 procedure, especially the process of moisture conditioning. The fracture energy results indicate that while mixes undergo reduced tensile strength, the overall capability of mix to strain without cracking significantly increased after AASHTO recommended moisture conditioning process. The study also included a set of samples that were field conditioned over the period of winter and spring months. The mechanical behavior of field conditioned samples was quite different as compared to those conditioned in lab using the AASHTO procedure.
  Authors: Dave, Eshan V.; Baker, Justin
  Authors: Dave, Eshan V.; Baker, Justin
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 597
  Paper Number: 13-4613
  Practice-Ready: Yes
• Effect of Temperature-Time History on Concrete Strength in Mass Concrete Structures
  Abstract: Concrete maturity method is a popular non-destructive testing method to estimate in-place strength development of concrete structures. Many state highway agencies adopted procedures for using maturity method to obtain better quality control while monitoring in-place strength development in real time. In this study, maturity method was used to estimate in-place strength of large concrete placements. Four 6-foot cube blocks were constructed in four different locations and calibration curves for those concrete mixtures were established using 6x12 inch cylinder specimens collected from the construction site. Temperature sensors were embedded in specific locations throughout the depth of the cubes, and the equivalent age of the in-place concrete was calculated. 4-inch diameter core samples, with 6-foot in length, were taken from the cubes at four-day after construction and the core strengths were compared with the predicted strengths using maturity. In addition, activation energy values were determined in the laboratory and used for equivalent age calculations as recommended in ASTM C 1074. According to the test results, the concrete top surface strength prediction is always higher than the actual core strength. For three cube constructions, core results from mid-section were close to the predicted strengths and core results from the bottom section were higher than the predicted values. Results show that in-place concrete strength is being influenced by several factors other than temperature, including the location of the sample in the structure, lack of compaction quality, higher air content and in-situ water-cement ratio, so that establishing a reliable maturity and in-place strength relationship is rather difficult within given circumstances. The results of this study provide useful information to examine the accuracy of the maturity method used in the estimation of in-place concrete strength in large structures.
  Authors: Yikici, Tahsin Alper; Chen, Roger H. L.
  Authors: Yikici, Tahsin Alper; Chen, Roger H. L.
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 286
  Paper Number: 13-4969
  Practice-Ready: Yes
• Fracture Energy Index Concept: Comparing Monotonic Loading Hot-Mix Asphalt Crack Tests
  Abstract:

  In this study, the concept of the Fracture Energy (FE) Index was explored as a fracture parameter to characterize and quantify the cracking resistance potential of hot-mix asphalt (HMA) mixes subjected to monotonic loading in the laboratory. Mathematically, the FE Index was defined as a parametric ratio of the total FE to the HMA tensile strength and tensile strain at peak failure load per unit crack length. The concept was put into practice by testing commonly used Texas HMA mixes, with cracking resistance potential ranging from poor to good, under the Overlay Tester -monotonic loading setup (OTM) along with two other more commonly used monotonic loading tests, namely: the Indirect Tensile Test (IDT) and the Semi-Circular Bending Test (SCB). Corresponding results indicated that the FE Index has promising potential to be used as a fracture parameter to discriminate and rank the cracking resistance potential of HMA mixes in the laboratory. As expected of monotonic loading crack tests, variability was within acceptable tolerances, except for the SCB that exhibited high variability, particularly at higher asphalt-binder contents. The FE Index also exhibited sensitivity to HMA mix-design variables such as the asphalt-binder content, particulalry for the OTM and IDT tests. Overall, the OTM and the IDT tests exhibited supperiority over the SCB test and would readily serve as surrogate crack tests for routine HMA mix-design and screening in the laboratory. The SCB test appeared to be better suited for low asphalt-binder content mixes and/or low temperature testing.

  Authors: Faruk, Abu Nayeem Md.; Walubita, Lubinda F.; Oh, Jeong Ho; Izzo, Richard; Haggerty, Brett; Scullion, Tom
  Authors: Faruk, Abu Nayeem Md.; Walubita, Lubinda F.; Oh, Jeong Ho; Izzo, Richard; Haggerty, Brett; Scullion, Tom
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 653
  Paper Number: 13-3422
• Effect of Temperature on Shear Strength of Recycled Asphalt Shingles
  Abstract:

  The effect of seasonal field temperature variations on shear strength of recycled asphalt shingles (RAS) improved by mixing with bottom ash (BA) was evaluated for use as structural fill material in highway embankments. Typical field temperatures ranging from 5 oC to 35 oC were induced to the compacted RAS:BA specimens. The increase in temperature reduced the shear strength of the compacted RAS:BA mixture and, therefore, temperature effects should be taken into consideration in design. The friction angle of the compacted RAS:BA mixtures, however, remains within a range suitable for stability of embankment fills. Thermal cycling induces thermal preloading to the mixtures containing RAS, which in turn increases shear strength. Based on these results, to achieve the optimum behavior, construction of highway embankments made with materials containing RAS is recommended during warm seasons. Use of RAS in high-volume structural fill applications can contribute to more sustainable roadway infrastructure.

  Authors: Soleimanbeigi, Ali; Edil, Tuncer B.; Tinjum, James M.
  Authors: Soleimanbeigi, Ali; Edil, Tuncer B.; Tinjum, James M.
  Year: 2013
  Document Type: Paper
  Subject: Geotechnology; Materials
  Session: 696
  Paper Number: 13-3109
  Practice-Ready: Yes
• Influence of Aggregate Packing and Asphalt Binder Characteristics on Performance of Stone Matrix Asphalt
  Authors: Apeagyei, Alex
  Authors: Apeagyei, Alex
  Year: 2013
  Document Type: Presentation
  Subject: Materials
  Session: 670
  Paper Number: 13-0622
• Evaluating Laboratory Compaction Techniques of Reclaimed Asphalt Pavement
  Authors: Cosentino, Paul
  Authors: Cosentino, Paul
  Year: 2013
  Document Type: Presentation
  Subject: Geotechnology; Materials; Pavements
  Session: 564
  Paper Number: 13-1220
• Evaluating Laboratory Compaction Techniques of Reclaimed Asphalt Pavement
  Authors: Bleakley, Albert
  Authors: Bleakley, Albert
  Year: 2013
  Document Type: Presentation
  Subject: Geotechnology; Materials; Pavements
  Session: 564
  Paper Number: 13-1220
• Thermomechanical Model to Study Impact of Internal Void Structure on Mechanical Performance of Asphalt Mixtures
  Authors: Castillo, Daniel
  Authors: Castillo, Daniel
  Year: 2013
  Document Type: Presentation
  Subject: Materials
  Session: 826
  Paper Number: 13-1420
• Thermomechanical Model to Study Impact of Internal Void Structure on Mechanical Performance of Asphalt Mixtures
  Authors: Caro, Silvia
  Authors: Caro, Silvia
  Year: 2013
  Document Type: Presentation
  Subject: Materials
  Session: 826
  Paper Number: 13-1420
• Cementitiously Stabilized Materials Using Ultrasonic Testing
  Authors: Edil, Tuncer
  Authors: Edil, Tuncer
  Year: 2013
  Document Type: Presentation
  Subject: Geotechnology; Materials; Pavements
  Session: 564
  Paper Number: 13-1435
• Evaluation of Rejuvenator's Effectiveness with Conventional Mix Testing for 100% RAP Mixtures
  Authors: Zaumanis, Martins
  Authors: Zaumanis, Martins
  Year: 2013
  Document Type: Presentation
  Subject: Materials; Pavements
  Session: 307
  Paper Number: 13-1447
• Maintenance Cost Justification for Chloride Treatment and Aggregate on Unsealed Roads
  Authors: Huntington, George
  Authors: Huntington, George
  Year: 2013
  Document Type: Presentation
  Subject: Geotechnology; Materials; Pavements
  Session: 740
  Paper Number: 13-1543
• Limit Analysis for Historic Masonry Bridge with CFRP Reinforcements
  Authors: Catalani, Giulio
  Authors: Catalani, Giulio
  Year: 2013
  Document Type: Presentation
  Subject: Bridges and Other Structures; Design; Materials
  Session: 300
  Paper Number: 13-1658
• Nanoscale Evaluation of Effect of RAP on Virgin Asphalt Binder Properties
  Authors: Nazzal, Munir
  Authors: Nazzal, Munir
  Year: 2013
  Document Type: Presentation
  Subject: Materials; Pavements
  Session: 307
  Paper Number: 13-0153
• Laser Spectrographic Pattern Matching for Rapid Mineral Aggregate Classification
  Authors: Chesner, Warren
  Authors: Chesner, Warren
  Year: 2013
  Document Type: Presentation
  Subject: Geotechnology; Materials
  Session: 745
  Paper Number: 13-0480
• Investigation of Factors Affecting Surface Resistivity Through Ruggedness Testing
  Authors: Icenogle, Patrick
  Authors: Icenogle, Patrick
  Year: 2013
  Document Type: Presentation
  Subject: Materials
  Session: 206
  Paper Number: 13-0727
• First Observation of Blending-Zone Morphology at Interface of Reclaimed Asphalt Binder and Virgin Bitumen
  Authors: Nahar, Sayeda
  Authors: Nahar, Sayeda
  Year: 2013
  Document Type: Presentation
  Subject: Materials; Pavements
  Session: 307
  Paper Number: 13-0763
• Effect of Air Content on Rapid Chloride Permeability
  Authors: Crouch, Lewis
  Authors: Crouch, Lewis
  Year: 2013
  Document Type: Presentation
  Subject: Bridges and Other Structures; Materials; Pavements
  Session: 162
  Paper Number: 13-0777
• PERFORMANCE OF FRP CONCRETE BEAMS EXPOSED TO SEVERE ENVIRONMENTS
  Authors: Zaki, Amr
  Authors: Zaki, Amr
  Year: 2013
  Document Type: Presentation
  Subject: Bridges and Other Structures; Design; Materials
  Session: 300
  Paper Number: 13-1833
• Reducing Specimen Size of Concrete Flexural Strength Test for Safety and Ease of Handling
  Authors: Ardani, Ahmad
  Authors: Ardani, Ahmad
  Year: 2013
  Document Type: Presentation
  Subject: Construction; Materials; Pavements
  Session: 427
  Paper Number: 13-1986
• Significance of Mixture Parameters on Binder Aging in Hot-Mix Asphalt Mixtures
  Authors: Morian, Nathan
  Authors: Morian, Nathan
  Year: 2013
  Document Type: Presentation
  Subject: Materials
  Session: 670
  Paper Number: 13-2070
• Ruggedness Study of Coefficient of Thermal Expansion of Concrete Test Method AASHTO T336
  Authors: Tanesi, Jussara
  Authors: Tanesi, Jussara
  Year: 2013
  Document Type: Presentation
  Subject: Materials
  Session: 206
  Paper Number: 13-2167
• Design and Constructability of Emulsion-Stabilized Bases for Full-Depth Reclamation
  Authors: Nazarian, Soheil
  Authors: Nazarian, Soheil
  Year: 2013
  Document Type: Presentation
  Subject: Geotechnology; Materials; Pavements
  Session: 740
  Paper Number: 13-2256
• Analysis of Temperature Effect on Bituminous Mixture Fatigue Behavior using the EBADE Test
  Authors: Perez-Jimenez, Felix
  Authors: Perez-Jimenez, Felix
  Year: 2013
  Document Type: Presentation
  Subject: Materials
  Session: 840
  Paper Number: 13-2477
• Laboratory Test Methods for Polishing Asphalt Surfaces and Predicting Their Skid Resistance
  Authors: Do, Minh-Tan
  Authors: Do, Minh-Tan
  Year: 2013
  Document Type: Presentation
  Subject: Materials; Pavements
  Session: 517
  Paper Number: 13-2444
• Evaluation of Environmental Susceptibility of Bituminous Mastic Viscosity as a Function of Mineral and Biomass Fillers
  Authors: Hesami, Ebrahim
  Authors: Hesami, Ebrahim
  Year: 2013
  Document Type: Presentation
  Subject: Materials
  Session: 743
  Paper Number: 13-2501
• Linear and Nonlinear Viscoelastic Analysis of Bituminous Mortar
  Authors: Woldekidan, Milliyon
  Authors: Woldekidan, Milliyon
  Year: 2013
  Document Type: Presentation
  Subject: Materials
  Session: 374
  Paper Number: 13-2557
• Effect of Air Content on Rapid Chloride Permeability
  Authors: Browning, Allen
  Authors: Browning, Allen
  Year: 2013
  Document Type: Presentation
  Subject: Bridges and Other Structures; Materials; Pavements
  Session: 162
  Paper Number: 13-0777
• Comparison of Gravimetric and Hardened Air Content with Pressure Method Air Content of Tennessee Bridge Deck Mixture
  Authors: Crouch, Lewis
  Authors: Crouch, Lewis
  Year: 2013
  Document Type: Presentation
  Subject: Bridges and Other Structures; Materials; Pavements
  Session: 162
  Paper Number: 13-0778
• Comparison of Gravimetric and Hardened Air Content with Pressure Method Air Content of Tennessee Bridge Deck Mixture
  Authors: Browning, Allen
  Authors: Browning, Allen
  Year: 2013
  Document Type: Presentation
  Subject: Bridges and Other Structures; Materials; Pavements
  Session: 162
  Paper Number: 13-0778
• Reducing Specimen Size of Concrete Flexural Strength Test for Safety and Ease of Handling
  Authors: Tanesi, Jussara
  Authors: Tanesi, Jussara
  Year: 2013
  Document Type: Presentation
  Subject: Construction; Materials; Pavements
  Session: 427
  Paper Number: 13-1986
• Measurement and Prediction of Coefficient of Thermal Expansion for Concrete Pavement Design in Georgia
  Authors: Kim, Sung-Hee
  Authors: Kim, Sung-Hee
  Year: 2013
  Document Type: Presentation
  Subject: Materials
  Session: 206
  Paper Number: 13-2727
• Measurement and Prediction of Coefficient of Thermal Expansion for Concrete Pavement Design in Georgia
  Authors: Jeong, Jin-Hoon
  Authors: Jeong, Jin-Hoon
  Year: 2013
  Document Type: Presentation
  Subject: Materials
  Session: 206
  Paper Number: 13-2727
• New Developments in Selecting Chemical Treatments for Gravel Roads
  Authors: Jones, David
  Authors: Jones, David
  Year: 2013
  Document Type: Presentation
  Subject: Geotechnology; Materials; Pavements
  Session: 740
  Paper Number: 13-2957
• Evaluation of Aggregate Imaging Techniques for Quantification of Morphological Characteristics
  Authors: Wang, Linbing
  Authors: Wang, Linbing
  Year: 2013
  Document Type: Presentation
  Subject: Geotechnology; Materials
  Session: 745
  Paper Number: 13-2955
• Review of Precast Portland Cement Concrete Panel Technologies for Use in Expedient Portland Cement Concrete Airfield Pavement Repairs
  Authors: Priddy, Lucy
  Authors: Priddy, Lucy
  Year: 2013
  Document Type: Presentation
  Subject: Construction; Materials; Pavements
  Session: 427
  Paper Number: 13-2956
• Effect of Temperature on Shear Strength of Recycled Asphalt Shingles
  Authors: Soleimanbeigi, Ali
  Authors: Soleimanbeigi, Ali
  Year: 2013
  Document Type: Presentation
  Subject: Geotechnology; Materials
  Session: 696
  Paper Number: 13-3109
• Development of Service-Life Model of I-99 High-Performance Concrete Bridge Decks in Pennsylvania
  Authors: Ghosh, Pratanu
  Authors: Ghosh, Pratanu
  Year: 2013
  Document Type: Presentation
  Subject: Bridges and Other Structures; Materials; Pavements
  Session: 162
  Paper Number: 13-3400
• Measurement of Subgrade Thermal Conductivity Using a Modified Triaxial Test
  Authors: McCartney, John
  Authors: McCartney, John
  Year: 2013
  Document Type: Presentation
  Subject: Geotechnology; Materials
  Session: 696
  Paper Number: 13-1866
• Evolution of Crossover Modulus with Oxidative Aging: Method to Estimate Change in Viscoelastic Properties of Asphalt Binder with Time and Depth on the Road
  Authors: Farrar, Michael
  Authors: Farrar, Michael
  Year: 2013
  Document Type: Presentation
  Subject: Materials
  Session: 374
  Paper Number: 13-3059
• Comparative Experimental Performance of Bridge Deck Slabs with AFRP and Steel Prestressed Precast Panels
  Authors: Head, Monique
  Authors: Head, Monique
  Year: 2013
  Document Type: Presentation
  Subject: Bridges and Other Structures; Design; Materials
  Session: 461
  Paper Number: 13-3207
• Effects of Shear Stress on Pavement Cracking and Interface Debonding: Case Study in Arkansas
  Authors: Zou, Xiaoling
  Authors: Zou, Xiaoling
  Year: 2013
  Document Type: Presentation
  Subject: Materials
  Session: 840
  Paper Number: 13-3506
• Flexural Behavior of Hybrid FRP-Ultra-High-Performance Fiber-Reinforced Concrete Composite Beams
  Authors: Nguyen, Hai
  Authors: Nguyen, Hai
  Year: 2013
  Document Type: Presentation
  Subject: Bridges and Other Structures; Design; Materials
  Session: 461
  Paper Number: 13-3699
• Aggregate Size and Shape Evaluation using Segmentation Techniques and Aggregate Image Processing Algorithms
  Authors: Moaveni, Maziar
  Authors: Moaveni, Maziar
  Year: 2013
  Document Type: Presentation
  Subject: Geotechnology; Materials
  Session: 745
  Paper Number: 13-4167
• Evaluation of Semiflexible Composite Mixture Using Indirect Tensile Tests
  Authors: Shen, Shihui
  Authors: Shen, Shihui
  Year: 2013
  Document Type: Presentation
  Subject: Materials
  Session: 670
  Paper Number: 13-4304
• Leaching of Alkaline Substances and Heavy Metals from Recycled Concrete Aggregate Used as Unbound Base Course
  Authors: Chen, Jiannan
  Authors: Chen, Jiannan
  Year: 2013
  Document Type: Presentation
  Subject: Geotechnology; Materials
  Session: 746
  Paper Number: 13-2412
• Automated Measurement and Control of Slump and Water Content for Concrete Quality Assurance
  Authors: Koehler, Eric
  Authors: Koehler, Eric
  Year: 2013
  Document Type: Presentation
  Subject: Construction; Materials; Pavements
  Session: 427
  Paper Number: 13-3031
• Assessment of Pavement Impacts due to Energy Developments in Texas
  Authors: Oh, Jeong Ho
  Authors: Oh, Jeong Ho
  Year: 2013
  Document Type: Presentation
  Subject: Maintenance and Preservation; Materials; Pavements
  Session: 808
  Paper Number: 13-2235
• Leaching Behavior of Aluminum, Arsenic, and Chromium from High-Carbon Fly-Ash Amended Highway Structural Fills
  Authors: Cetin, Bora
  Authors: Cetin, Bora
  Year: 2013
  Document Type: Presentation
  Subject: Geotechnology; Materials
  Session: 746
  Paper Number: 13-2251
• Influence of BituTech RAP Bioasphalt on Viscoelastic Properties of Reclaimed Asphalt Mixtures
  Authors: Hajj, Elie
  Authors: Hajj, Elie
  Year: 2013
  Document Type: Presentation
  Subject: Materials
  Session: 743
  Paper Number: 13-2253
• Assessment of Warm-Mix Asphalt for Heavy-Traffic Airfields
  Authors: Rushing, John
  Authors: Rushing, John
  Year: 2013
  Document Type: Presentation
  Subject: Materials
  Session: 704
  Paper Number: 13-3017
• Externally Bonded GFRP and NSM Steel Bars for Enhanced Strengthening of Concrete T-beams
  Authors: Wuertz, Augustine
  Authors: Wuertz, Augustine
  Year: 2013
  Document Type: Presentation
  Subject: Bridges and Other Structures; Design; Materials
  Session: 461
  Paper Number: 13-3120
• Local Practice of Assessing Dynamic Modulus Properties for Washington State Mixtures
  Authors: Shen, Shihui
  Authors: Shen, Shihui
  Year: 2013
  Document Type: Presentation
  Subject: Materials
  Session: 826
  Paper Number: 13-4181
• Experimental Evaluation of Connections in Hybrid FRP-Concrete Bridge Truss Girders
  Authors: El-Badry, Mamdouh
  Authors: El-Badry, Mamdouh
  Year: 2013
  Document Type: Presentation
  Subject: Bridges and Other Structures; Design; Materials
  Session: 461
  Paper Number: 13-4134
• Stiffness Evolution of Granular Materials Stabilized with Foamed Bitumen and Cement
  Authors: Halles, Felipe
  Authors: Halles, Felipe
  Year: 2013
  Document Type: Presentation
  Subject: Geotechnology; Materials; Pavements
  Session: 740
  Paper Number: 13-4177
• Asphalt Binder Contribution to Mixture Workability and Application of Asphalt Lubricity Test to Estimate Compactability Temperatures for Warm-Mix Asphalt
  Authors: Hanz, Andrew
  Authors: Hanz, Andrew
  Year: 2013
  Document Type: Presentation
  Subject: Materials
  Session: 704
  Paper Number: 13-4332
• 4.75-mm SMA on Thin Durable Asphalt Overlays
  Authors: Son, Songsu
  Authors: Son, Songsu
  Year: 2013
  Document Type: Presentation
  Subject: Materials; Pavements
  Session: 517
  Paper Number: 13-4378
• Analytical and Laser Scanning Techniques to Determine Shape Properties of Mineral Aggregates
  Authors: Anochie-Boateng, Joseph
  Authors: Anochie-Boateng, Joseph
  Year: 2013
  Document Type: Presentation
  Subject: Geotechnology; Materials
  Session: 745
  Paper Number: 13-4454
• Evaluation of Low-Temperature Properties of Asphalt Binders and Mixtures
  Authors: Premkumar, Laxmikanth
  Authors: Premkumar, Laxmikanth
  Year: 2013
  Document Type: Presentation
  Subject: Materials
  Session: 374
  Paper Number: 13-4529
• Estimation of Subgrade Resilient Modulus Using Unconfined Compression Test
  Authors: Hossain, Shabbir
  Authors: Hossain, Shabbir
  Year: 2013
  Document Type: Presentation
  Subject: Geotechnology; Materials; Pavements
  Session: 564
  Paper Number: 13-4564
• Comparison Between Mechanistic Properties of Laboratory and Field-Produced Warm-Mix Asphalt Mixtures from Manitoba, Canada
  Authors: Hajj, Elie
  Authors: Hajj, Elie
  Year: 2013
  Document Type: Presentation
  Subject: Materials
  Session: 704
  Paper Number: 13-4603
• Effect of Warm-Mix Technologies and Testing Protocol on Moisture Susceptibility of Asphalt Mixtures
  Authors: Willis, James
  Authors: Willis, James
  Year: 2013
  Document Type: Presentation
  Subject: Materials
  Session: 467
  Paper Number: 13-4673
• Continuum-Coupled Moisture-Mechanical Damage Model for Asphalt Concrete
  Authors: Shakiba, Maryam
  Authors: Shakiba, Maryam
  Year: 2013
  Document Type: Presentation
  Subject: Materials
  Session: 467
  Paper Number: 13-4763
• Field and Laboratory Evaluation of Winter Season Pavement Patching Materials in Tennessee
  Authors: Huang, Baoshan
  Authors: Huang, Baoshan
  Year: 2013
  Document Type: Presentation
  Subject: Maintenance and Preservation; Materials; Pavements
  Session: 808
  Paper Number: 13-4772
• Evaluating Rut Resistance Performance of Warm-Mix Asphalts in North Dakota
  Authors: Suleiman, Nabil
  Authors: Suleiman, Nabil
  Year: 2013
  Document Type: Presentation
  Subject: Materials
  Session: 704
  Paper Number: 13-4855
• Effectiveness of Antistrip Agents in Asphalt Mixtures
  Authors: Watson, Donald
  Authors: Watson, Donald
  Year: 2013
  Document Type: Presentation
  Subject: Materials
  Session: 670
  Paper Number: 13-5061
• Scanning Laser Detection of Crack Precursors in High RAP Content Asphalt Mixture with Improved Fatigue Performance
  Authors: Ajideh, Hossein
  Authors: Ajideh, Hossein
  Year: 2013
  Document Type: Presentation
  Subject: Materials
  Session: 840
  Paper Number: 13-5136
• Use of Moisture-Induced Stress Testing to Evaluate Stripping Potential of Hot-Mix Asphalt
  Authors: Pinkham, Rudy
  Authors: Pinkham, Rudy
  Year: 2013
  Document Type: Presentation
  Subject: Materials
  Session: 467
  Paper Number: 13-4538
• Influence of Cecabase on Mechanistic, Economical, and Environmental Attributes of Polymer-Modified Asphalt Mixture
  Authors: Hajj, Elie
  Authors: Hajj, Elie
  Year: 2013
  Document Type: Presentation
  Subject: Materials
  Session: 743
  Paper Number: 13-3133
• Development of Predictive Model for Laboratory Compaction of Asphalt Mixtures
  Authors: Kassem, Emad
  Authors: Kassem, Emad
  Year: 2013
  Document Type: Presentation
  Subject: Materials
  Session: 826
  Paper Number: 13-5250
• Investigation of Possible Chloride Contamination in Posttensioning Grout
  Authors: Kelley, Paul
  Authors: Kelley, Paul
  Year: 2013
  Document Type: Presentation
  Subject: Bridges and Other Structures; Maintenance and Preservation; Materials
  Session: 464
  Paper Number: P13-5034
• Protocols for Inspecting Tendons Embedded in Grout with Potentially Elevated Chlorides
  Authors: Kelley, Paul
  Authors: Kelley, Paul
  Year: 2013
  Document Type: Presentation
  Subject: Bridges and Other Structures;