2013 Session: 555

• Three-dimensional Finite Element Analysis of Hot-Mix Asphalt Overlay Mix Design to Control Reflective Cracking
  Abstract: This study examines the effectiveness of HMA overlay design strategies for the purpose of controlling the development of reflective cracking. A parametric study was conducted using a 3D Finite Element (FE) model of a rigid pavement section including Linear Viscoelastic (LVE) material properties for the Hot Mix Asphalt (HMA) overlay and non-uniform tire-pavement contact stresses. Several asphalt mixtures were tested in the surface, intermediate, and leveling course of the HMA overlay. Results obtained show that no benefits can be anticipated by using either Polymer-Modified (PM) or Dense-Graded (DG) mixtures instead of Standard Binder (SB) mixtures in the surface or intermediate course. For the leveling course, the use of a PM asphalt binder was found beneficial in terms of mitigating reflective cracking. As compared to the SB mix, the use of PM asphalt mixture in the leveling course reduced the level of longitudinal tensile stress at the bottom of the HMA overlay above the PCC joint by approximately 30%.
  Authors: Ghauch, Ziad
  Authors: Ghauch, Ziad
  Year: 2013
  Document Type: Paper
  Subject: Design; Pavements
  Session: 555
  Paper Number: 13-0223
• Hot In-Place Recycling of Open-Graded Friction Course
  Abstract: ABSTRACTOpen graded friction course (OGFC) is widely used in Florida and many southern states as a final friction surface in high speed roads. FDOT friction policy requires the use of OGFC on multilane highway facilities with design speeds greater than 50 miles per hour. OGFC reduces the possibility of hydroplaning and water splash during rain, thereby reducing crashes. About half the Florida State Highway System is surfaced with OGFC, amounting to about 22,000 lane miles of roads.The use of FC-5, the current OGFC mix type in Florida, started in 2000. Some roads with FC-5 have reached the end of their useful life and have been milled and resurfaced. Given the high cost of FC-5 mix, it made economic sense to try to reuse the prime aggregate and high quality material incorporated in OGFC using the hot in-place recycling (HIR) process. The HIR process heats, hot-mills the surface pavement layer, applies a rejuvenating agent, mixes and then places the material in one pass. The process uses 100% of the existing road material and can produce significant cost and environmental savings (1).This paper reports on three attempts to hot in-place recycle OGFC in Florida. One was to hot in-place recycle an FC-5 mix as part of a hot in-place recycling project in Pasco County, Florida (SR-54) in 2012. The second is laboratory study of recycling FC-5 mix based on samples taken at SR-60 in Polk County, Florida in 2011. The third references SR-471 case study conducted by FDOT in 2002 in which an OGFC (type FC-2) was hot in-place recycled, lasted 10 years to date and still remains in service.The three referenced projects have shown that HIR of OGFC can be done successfully and should be considered as a cost effective rehabilitation option in the future. FC-5 is 0.75 inch thick. The recycling thickness for successful HIR is 1.0 to 2.5 inches. Thus, recycling FC-5 requires blending it with the dense-graded mix beneath it. The blending ratio of the two mixes depends on the thickness of each layer. The gradation of the recycled mix was dense graded. The blending ratio can be varied by changing the recycling depth and can produce either coarse or fine mix. While the recycled mix is not open- graded and does not meet FDOT’s requirement, it provides an economical option to milling and resurfacing OGFC. That option is to recycle the old OGFC into the structural layer and resurface with a new OGFC. Current resurfacing practice entails milling the FC-5 and a portion of the structural layer underneath it, replacing the structural layer then replacing the FC-5 course. FC-5 cannot be overlaid and must be removed before overlay. The OGFC can be in-place recycled and mixed with the structural layer underneath, and then a new friction course can be placed over the recycled mix. This can save money as it eliminates the need to mill and replace the top structural layer under the FC-5. Raising the road grade by 0.75 inch, the thickness of the new FC-5 layer, while increasing the section’s structural number, remains an issue in this approach. This may be acceptable if there are no limitations on raising the road elevation in the selected project.Among the interesting findings is the increased amount of fines in the mix compared to construction gradation. Over time, the voids in the mix get filled with dirt and dust. Water flow brings fines into the mix and as the water evaporates, it leaves the fines in the voids, reducing the drainage capacity and resulting in a finer mix.
  Authors: Ali, Hesham A.; Sayed, Sayed M.
  Authors: Ali, Hesham A.; Sayed, Sayed M.
  Year: 2013
  Document Type: Paper
  Subject: Design; Pavements
  Session: 555
  Paper Number: 13-0924
• Premature Cracking in Foamed Asphalt Pavement: Peru-Brazil Highway Case Study
  Abstract: The granular base stabilization with foamed bitumen is an alternative whose application is expanding by the increasing demand to preserve and minimize the use of virgin materials and reduce energy consumption. The purpose of this paper is to analyze the origin of premature cracks in the asphalt foaming of the road section I of Brazil Peru that began within hours of completion of the construction process and the evolution continued even when the surface treatment was placed. The scope of this work includes the evaluation and analysis of three critical components, the construction process, the mix design and structural capacity based on an extensive laboratory program and in situ evaluations. The total extension of the project is 470 miles, with foamed bitumen sections of 200 miles (the largest section of foamed bitumen built in South America) of which approximately 50 miles showed premature failure. The failures were mainly concentrated in areas with altitudes between 8,000 and 15,000 feet above sea level. Premature cracks were mainly due to a combination of poor curing process, low relative humidity, excessive fines content, and reduced structural capacity. It is recommended that similar projects should consider an early curing process, a quick surface seal, and adopt standards that consider at least a minimum required thickness, a tolerable range for fine contents, and a maximum allowable deflection.
  Authors: Menendez, Jose Rafael
  Authors: Menendez, Jose Rafael
  Year: 2013
  Document Type: Paper
  Subject: Design; Pavements
  Session: 555
  Paper Number: 13-2381
• Responses and Performance of Stabilized Full-Depth Reclaimed Pavements at MnROAD
  Abstract: This paper details the efforts regarding the construction and analysis of three stabilized full-depth reclamation (SFDR) sections (cells 2, 3, and 4) constructed at the Minnesota Road Research Facility (MnROAD) on I-94 in 2008. Three test sections with varying pulverized asphalt concrete/granular base ratios were constructed in order to study the performance of full-depth reclaimed (FDR) pavements stabilized with engineered emulsion. Emulsion content and base structure varied between test sections. Each test section was designed for 3.5 million ESALs over a period of five years. The sections have been subjected to approximately 2.2 million ESALs as of 30 June 2012.Strain gages were embedded at the bottom of the hot-mix asphalt (HMA) and SFDR layers in each test section to measure responses. The strain gages indicate that both the bottom of the HMA and SFDR layers are subject to horizontal tensile strain from falling weight deflectometer (FWD) and heavy vehicle loading. Pavement performance in terms of rutting, cracking, and international roughness index (IRI) has been measured periodically. The results indicate that all three cells are performing well. The only crack in the three cells exists in cell 3, IRI values are well within the acceptable range, and rutting, while progressing, is still acceptable. Finally, the paper concludes with modeled responses and performance predictions from DARWinME and BISAR. Model predictions indicate that a SFDR layer will provide greater structural benefits and increased performance than similar structures with unstabilized FDR or granular base layers.
  Authors: Johanneck, Luke A; Dai, Shongtao
  Authors: Johanneck, Luke A; Dai, Shongtao
  Year: 2013
  Document Type: Paper
  Subject: Design; Pavements
  Session: 555
  Paper Number: 13-3135
• Recycling of Urban Road Using Foam Bitumen: Indian Experience
  Abstract: Recycling of pavements is a relatively new technique in India and gaining popularity in recent times due to several merits over conventional pavement rehabilitation techniques. The first recycling work of flexible pavements was undertaken nearly a decade ago and since then milling and recycling of pavements has been adopted in some parts of urban and high volume roads in India. However there have been no research studies reported on these works. In recent times, foam bitumen recycled pavement work was undertaken on some urban roads of Kolkata city in India, Detailed investigation on milling and foam bitumen recycling work of these pavements was performed and presented in this paper. Laboratory investigation on milled and recycled material, field evaluation using Falling weight deflectometer (FWD) before and after rehabilitation was carried out.. Results indicate that the foam bitumen recycling is a very promising alternative to rehabilitate the pavements and to address the concern of conservation of energy and natural resources.
  Authors: Muppi Reddy, Amaranath Reddy; Reddy, K. Sudhakar; Pandey, Braj Bushan
  Authors: Muppi Reddy, Amaranath Reddy; Reddy, K. Sudhakar; Pandey, Braj Bushan
  Year: 2013
  Document Type: Paper
  Subject: Design; Pavements
  Session: 555
  Paper Number: 13-3740
• Laboratory and Field Evaluation of Cold-in-Place RAP Recycling
  Abstract: Cold in-place recycling (CIR) is a viable pavement rehabilitation technique that recycles 100% of the reclaimed asphalt pavement (RAP) in situ, without heat. Six test sections were constructed on a heavy traffic road in the south of Brazil using CIR with cement and cationic slow set polymer modified emulsion (CSS-1P). Different thickness of the recycled layer (80mm, 110mm, and 150mm) and two types of asphalt surface layers (HMA and Microsurfacing) were investigated. The RAP was sampled during the recycling operations and brought to the laboratory for its characterization and further mechanical tests evaluation (tensile strength, moisture sensitivity, and triaxial resilient modulus). Field samples were obtained from the test sections to evaluate the performance of recycled mixture. They were tested for rutting resistance (LCPC wheel tracking test) and indirect tensile resilient modulus. Structural evaluation of the test sections were performed through the FWD in different seasons of the year. It was observe a decrease in the modulus of the recycled layers during the rainy season, in comparison with the dry season results. The laboratory tests also indicated a moderate moisture sensitivity material. The backcalculated resilient moduli of the CIR layer presented the same order of magnitude of the moduli obtained in the laboratory tests. The CIR presented reduced permanent deformation in the laboratory and low rutting in the field after two years of the rehabilitation.
  Authors: Marcandali da Silva, Amanda Helena; Vasconcelos, Kamilla L.; Aranha, Ana Luisa; Bernucci, Liedi Bariani; Chaves, José Mario
  Authors: Marcandali da Silva, Amanda Helena; Vasconcelos, Kamilla L.; Aranha, Ana Luisa; Bernucci, Liedi Bariani; Chaves, José Mario
  Year: 2013
  Document Type: Paper
  Subject: Design; Pavements
  Session: 555
  Paper Number: 13-4178
• Three-dimensional Finite Element Analysis of Hot-Mix Asphalt Overlay Mix Design to Control Reflective Cracking
  Authors: Ghauch, Ziad
  Authors: Ghauch, Ziad
  Year: 2013
  Document Type: Presentation; Poster
  Subject: Design; Pavements
  Session: 555
  Paper Number: 13-0223
• Premature Cracking in Foamed Asphalt Pavement: Peru-Brazil Highway Case Study
  Authors: Menendez, Jose
  Authors: Menendez, Jose
  Year: 2013
  Document Type: Presentation; Poster
  Subject: Design; Pavements
  Session: 555
  Paper Number: 13-2381
• Responses and Performance of Stabilized Full-Depth Reclaimed Pavements at MnROAD
  Authors: Johanneck, Luke
  Authors: Johanneck, Luke
  Year: 2013
  Document Type: Presentation; Poster
  Subject: Design; Pavements
  Session: 555
  Paper Number: 13-3135
• Recycling of Urban Road Using Foam Bitumen: Indian Experience
  Authors: Pandey, Braj
  Authors: Pandey, Braj
  Year: 2013
  Document Type: Presentation; Poster
  Subject: Design; Pavements
  Session: 555
  Paper Number: 13-3740