Application of a General Methodology to Analyze Strain Data Obtained from Accelerated Pavement Testing

This study demonstrates the application of a general methodology that was developed by Francois et al. (2019) to analyze strain data collected during accelerated pavement testing on flexible or composite pavements sections. Five instrumented, full-scale test sections were evaluated in this study. The sections had similar supporting layers however, each section contained different asphalt overlay mixtures as their surface course. Section 1 contained a 76.2 mm, stone matrix asphalt overlay while section 2 contained a 50.2 mm, New Jersey high performance thin overlay. Sections 3, 4 and 5 contained a 50.2 mm, Superpave mixture, stone matrix asphalt mixture, and New Jersey High performance thin overlay respectively, placed on top of a 25.4 mm, binder rich intermediate course. The sections were loaded using a 60 kN, heavy vehicle simulator wheel load. Loading was applied uni-directionally at 8 km/h for 200,000 loading passes. Two parameters obtained from the general methodology; the stiffness index and damage index parameters, were computed using recorded strain measurements from all five sections. The relative reflection cracking susceptibility of all the sections were then evaluated and ranked based on these parameters. The APT strain data analysis procedure was successfully used to distinguish the fatigue resistance of asphalt overlays. The NJHPTO & BRIC overlay was found to be the most crack susceptible mixture to while the SMA overlay was found to be the least vulnerable to cracking.