2013 Session: 574

• Effects of Asphalt Concrete Anisotropy on Predicted Pavement Response at High Temperatures
  Abstract: In this study, predictions of strain gauge calibrated full-scale micromechanical (MM) finite element (FE) models were used to identify the effects of asphalt concrete anisotropy on predicted asphalt concrete pavement performance. The accuracy of layered elastic theory (LET) models that are used in pavement design today were also evaluated. The MM FE model was first developed to simulate a laboratory shear test. Second, model parameters determined for the laboratory shear tests were used to develop MM FE models for full-scale pavement test sections. A virtual strain gauge was also included in the MM FE models for calibration. LET models were also calibrated using the measured strain gauge responses. Predictions of calibrated MM FE and LET models were compared to determine the effects of the absence of anisotropy in LET models on predicted pavement responses. Recommendations were also made for future use of the MM FE models to improve the predictive capability of LET models.
  Authors: Coleri, Erdem; Harvey, John
  Authors: Coleri, Erdem; Harvey, John
  Year: 2013
  Document Type: Paper
  Subject: Design; Pavements
  Session: 574
  Paper Number: 13-2166
• Evaluation of the Structural Response of Cracked Pavements at CEDEX Test Track
  Abstract: Flexible pavement structural response is typically modeled by using multilayer linear elastic theory. This is applicable to almost all mechanistic-empirical design procedures, but also in other fields of pavement engineering, like the interpretation of deflection data in order to assess pavement structural condition. The applicability of this theory, even with some limitations, has been validated for new or undamaged pavements, where the hypothesis of continuity is reasonably realistic. But still an effort is required in order to understand the structural response of damaged pavements, where the presence of discrete cracks is not compatible with continuum mechanics theories.Three flexible sections were instrumented with sensors in order to measure the structural response under moving vehicles at CEDEX test track. The response was systematically measured in terms of different response variables during a full-scale experiment where 1.3 million loads where applied. Structural response measured at the beginning of the experiment, when asphalt damage was null, was used as a reference in order to compare the evolution during the test. It was shown that the evolution of the different response variables can be explained by continuum mechanics, in particular by linear elasticity, as soon as asphalt damage is uniformly distributed in the material. As soon as discrete cracking appears, response stars to deviate from that predicted by multilayer linear elastic models.The importance of adopting a rational approach for the determination of the modulus of the asphalt layers is also shown in this paper.
  Authors: Mateos, Angel; Ayuso, Javier P.; Cadavid Jáuregui, Belén
  Authors: Mateos, Angel; Ayuso, Javier P.; Cadavid Jáuregui, Belén
  Year: 2013
  Document Type: Paper
  Subject: Design; Pavements
  Session: 574
  Paper Number: 13-4458
• Evaluation of a Heavy Polymer-Modified Binder Through Accelerated Pavement Testing
  Abstract: In 2001, the Florida Department of Transportation (FDOT) conducted an experimental study to assess the effect of polymer modified PG76-22 asphalt binder on rutting resistance of Superpave mixtures through Accelerated Pavement Testing (APT). The success of this study led to the use of PG76-22 binder on the final structural course for traffic level D (10 to > 30 million equivalent single axle loads, or ESALs) mixtures and the top two structural courses for traffic level E (¡Ý 30 million ESALs) mixtures. At times, however, localized failures still do occur at locations with concentrated truck traffic and low speeds. In response, a follow-up APT study was conducted to evaluate the performance of a polymer-modified asphalt binder meeting PG82-22 requirements. Results of the study indicated that the use of a heavy polymer modified binder improved rutting and cracking performance of asphalt mixtures.
  Authors: Greene, James; Choubane, Bouzid; Chun, Sanghyun
  Authors: Greene, James; Choubane, Bouzid; Chun, Sanghyun
  Year: 2013
  Document Type: Paper
  Subject: Design; Pavements
  Session: 574
  Paper Number: 13-2150
  Practice-Ready: Yes
• Porous Asphalt Performance in Cold Climate: Research at MnROAD
  Abstract: There is limited data on full-depth porous asphalt (PA) pavement performance in wet-freeze regions in the USA. To further study cold-weather PA performance, research was performed at the Minnesota Road Research (MnROAD) Low Volume Road (LVR). The objective of this research was to study the durability, maintenance requirements, hydrologic benefits, and environmental considerations of a full-depth porous asphalt (PA) pavement, installed on a low-volume roadway in a cold climate. To meet the objective, two porous asphalt test cells were constructed on the LVR test loop. One porous asphalt cell was constructed over a sand subgrade (MnROAD cell 86) and one over a clay subgrade (cell 88). In addition, a sealed/impervious, dense graded hot mix asphalt (DGHMA) control section (cell 87) was constructed directly adjacent to the porous sections, for comparison of water runoff, pavement performance and durability.This paper summarizes the mixture design, thickness determination, construction, and performance aspects of the porous asphalt test cells. The data presented herein describes the PA cells after the first three years of service (December 2008 to December 2011) and approximately 40,000 applied asphalt equivalent single axle loads (ESALs). The PA test cells performed well, in spite of what is considered to be significant loading for this type of pavement. The significant pavement distresses observed were rutting in the loaded lane and shallow surface raveling. Findings resulting from this study and ongoing monitoring of the test cells will contribute to the design and maintenance of full-depth porous asphalt pavements in Minnesota and other cold climates. Data collection for the initial project ended in December 2011, the final report was published in April. 2012.
  Authors: Dai, Shongtao; Lebens, Matthew
  Authors: Dai, Shongtao; Lebens, Matthew
  Year: 2013
  Document Type: Paper
  Subject: Design; Pavements
  Session: 574
  Paper Number: 13-4381
  Practice-Ready: Yes
• Evaluation of a Heavy Polymer-Modified Binder Through Accelerated Pavement Testing
  Authors: Greene, James
  Authors: Greene, James
  Year: 2013
  Document Type: Presentation
  Subject: Design; Pavements
  Session: 574
  Paper Number: 13-2150
• Effects of Asphalt Concrete Anisotropy on Predicted Pavement Response at High Temperatures
  Authors: Coleri, Erdem
  Authors: Coleri, Erdem
  Year: 2013
  Document Type: Presentation
  Subject: Design; Pavements
  Session: 574
  Paper Number: 13-2166
• Porous Asphalt Performance in Cold Climate: Research at MnROAD
  Authors: Dai, Shongtao
  Authors: Dai, Shongtao
  Year: 2013
  Document Type: Presentation
  Subject: Design; Pavements
  Session: 574
  Paper Number: 13-4381
• Evaluation of the Structural Response of Cracked Pavements at CEDEX Test Track
  Authors: Mateos, Angel
  Authors: Mateos, Angel
  Year: 2013
  Document Type: Presentation
  Subject: Design; Pavements
  Session: 574
  Paper Number: 13-4458