2013 Session: 207

• Innovative Approach for Asphalt Pavement Compaction Monitoring Using Ground-Penetrating Radar
  Abstract: This paper demonstrates that ground penetrating radar (GPR) is an effective tool for quality assurance and quality control during flexible pavement compaction and after construction. Density is one of the most important properties of asphalt concrete layers in flexible pavement. It is critical to monitor the asphalt concrete density change during compaction. GPR is able to measure the asphalt mixture density non-destructively and rapidly. However, it is challenging to apply GPR method during compaction because of the unknown effect of roller-sprayed water on the GPR signal. This paper presents a study on the effect of surface water to the GPR signal when a 2-GHz antenna is used. It is found that the higher frequency components of the ultra-wide band signal are affected by the water, but the lower frequency components are not significantly influenced. The process comprises a band-pass filter with passing band from 200 MHz to 800 MHz, and extracting surface reflection amplitude after filtering. The extracted feature is found to be insensitive to the presence of surface water. Thus, this technology can be used effectively during the compaction process. Field data collected from two construction projects were used for validating this approach. The proposed approach was found to be feasible to monitor compaction status. The thickness and density profiles were also obtained by GPR after the construction. The density values from GPR were similar to those obtained by nuclear gauge.
  Authors: Shangguan, Pengcheng; Al-Qadi, Imad L.; Leng, Zhen; Schmitt, Robert; Faheem, Ahmed Fatin
  Authors: Shangguan, Pengcheng; Al-Qadi, Imad L.; Leng, Zhen; Schmitt, Robert; Faheem, Ahmed Fatin
  Year: 2013
  Document Type: Paper
  Subject: Construction; Pavements
  Session: 207
  Paper Number: 13-2425
• Portable Seismic Pavement Analyzer for Paving Quality Assurance
  Abstract: Standard practice for evaluating flexible pavement construction focuses primarily on the compacted relative density of the pavement layer as means for quality assurance. Despite this trend, numerous studies show that mixtures compacted at the same density level may perform differently with respect to durability and mechanical stability. This paper investigates the potential of using the portable seismic pavement analyzer (PSPA) as quality assurance method during construction. The PSPA is used to estimate the seismic modulus of the pavement structure based on response to seismic excitation. The method repeatability was found to be acceptable; however, temperature must be factored for field quality assurance. The results show that seismic modulus testing is capable of identifying problematic areas within the pavement; specifically along the centerline longitudinal joint. The PSPA measurements were successfully correlated to the asphalt mixture voids in mineral aggregate (VMA) as determined in the laboratory, while the relative density showed no correlation with any of the mixture volumetric properties. Preliminary guidelines are proposed for using the PSPA as a tool for quality assurance to ensure that the final product meets expected service loads.
  Authors: Faheem, Ahmed Fatin; Schmitt, Robert; Al-Qadi, Imad L.
  Authors: Faheem, Ahmed Fatin; Schmitt, Robert; Al-Qadi, Imad L.
  Year: 2013
  Document Type: Paper
  Subject: Construction; Pavements
  Session: 207
  Paper Number: 13-4791
• Haul Time Effects on Unmodified, Foamed, and Additive-Modified Binders Used in Hot-Mix Asphalt
  Abstract: In recent years, “warm” technologies have made enormous changes to the flexible pavement industry in a variety of manners. Warm mix asphalt (WMA) is the most recognizable “warm” technology product, though there are other advantages associated with better compaction over a wide range of temperatures that have made very long haul distances appealing for some applications. This paper focuses on using warm mix technology at traditional hot mix production temperatures for the purpose of facilitating very long haul distances. The primary objective of this paper was to investigate how binder related properties change with haul time when material is mixed at hot mix temperatures, and a secondary objective was to determine if any behavioral differences were present between asphalt binders with no additive, foamed asphalt binders, and asphalt binders with a chemical additive. Plant mixed asphalt was used for the investigation. The overall conclusion of the research was that haul times of 1 to 8 hr produced no major differences in aging for a given binder type or between binder types. Subtle differences were observed between binder types in some instances (e.g. low temperature properties were slightly better for mixes using warm mix technologies relative to the one that did not use warm mix technology).
  Authors: Howard, Isaac L.; Baumgardner, Gaylon L.; Jordan, Walter Stephens; Menapace, Andrew Michael; Mogawer, Walaa S.; Hemsley, Mike
  Authors: Howard, Isaac L.; Baumgardner, Gaylon L.; Jordan, Walter Stephens; Menapace, Andrew Michael; Mogawer, Walaa S.; Hemsley, Mike
  Year: 2013
  Document Type: Paper
  Subject: Construction; Pavements
  Session: 207
  Paper Number: 13-3093
  Practice-Ready: Yes
• Evaluation of Non-Nuclear-Density Gauges for Measuring In-Place Density of Hot-Mix Asphalt
  Abstract: Ensuring that the hot mix asphalt (HMA) mat is compacted uniformly to an adequate density is critical to the performance of a pavement structure. Nuclear density gauges (NDGs) have been used for many years in pavement construction as a method of nondestructive density testing. Non-nuclear density gauges (NNDGs) perform the same function as NDGs. However, because NNDGs does not contain a nuclear source material, they are not subject to the same extensive fees and regulations as NDGs. Field and laboratory test results for two NNDGs, the Troxler PaveTracker and Transtech PQI 301 (referred to simply as the PQI in this paper), are analyzed in this paper to determine if NNDGs can serve as viable replacements for NDGs. Several potential factors that could affect the accuracy of NNDGs are examined. Global factors, such as aggregate mineralogy, the nominal maximum size of aggregate, HMA class, and aggregate absorption, are shown not to affect NNDGs stastistically significantly. Local factors, such as surface markings, likewise are shown not to have a statistically significant effect on NNDG readings. However, temperature and moisture are shown to affect NNDG readings. Overall, both the PaveTracker and PQI devices appear to be valid replacements for NDGs for quality assurance purposes, provided that the temperature and moisture conditions are met.
  Authors: Timm, Anthony; Wen, Haifang; Sharma, Sunil; Rose, Mark
  Authors: Timm, Anthony; Wen, Haifang; Sharma, Sunil; Rose, Mark
  Year: 2013
  Document Type: Paper
  Subject: Construction; Pavements
  Session: 207
  Paper Number: 13-3779
  Practice-Ready: Yes
• Innovative Approach for Asphalt Pavement Compaction Monitoring Using Ground-Penetrating Radar
  Authors: Shangguan, Pengcheng
  Authors: Shangguan, Pengcheng
  Year: 2013
  Document Type: Presentation
  Subject: Construction; Pavements
  Session: 207
  Paper Number: 13-2425
• Innovative Approach for Asphalt Pavement Compaction Monitoring Using Ground-Penetrating Radar
  Authors: Al-Qadi, Imad
  Authors: Al-Qadi, Imad
  Year: 2013
  Document Type: Presentation
  Subject: Construction; Pavements
  Session: 207
  Paper Number: 13-2425
• Haul Time Effects on Unmodified, Foamed, and Additive-Modified Binders Used in Hot-Mix Asphalt
  Authors: Howard, Isaac
  Authors: Howard, Isaac
  Year: 2013
  Document Type: Presentation
  Subject: Construction; Pavements
  Session: 207
  Paper Number: 13-3093
• Evaluation of Non-Nuclear-Density Gauges for Measuring In-Place Density of Hot-Mix Asphalt
  Authors: Timm, Anthony
  Authors: Timm, Anthony
  Year: 2013
  Document Type: Presentation
  Subject: Construction; Pavements
  Session: 207
  Paper Number: 13-3779
• Evaluation of Non-Nuclear-Density Gauges for Measuring In-Place Density of Hot-Mix Asphalt
  Authors: Rose, Mark
  Authors: Rose, Mark
  Year: 2013
  Document Type: Presentation
  Subject: Construction; Pavements
  Session: 207
  Paper Number: 13-3779
• Portable Seismic Pavement Analyzer for Paving Quality Assurance
  Authors: Faheem, Ahmed
  Authors: Faheem, Ahmed
  Year: 2013
  Document Type: Presentation
  Subject: Construction; Pavements
  Session: 207
  Paper Number: 13-4791