Correlating Laboratory Conditioning and Field Performance in Permeable Friction Course Asphalt Mixtures

Abstract

Permeable Friction Course (PFC) is a type of hot mix asphalt (HMA) mixture designed to allow water to freely flow through it. PFC is used as a surface course on high-speed roadways to reduce standing water and eliminate hydroplaning. Additional benefits include improved visibility, safety, and driver comfort. Despite its many benefits the material is plagued by a shorter service life than dense-graded HMA due to its susceptibility to moisture damage which manifests through its primary pavement distress – raveling. The objective of this study was to recommend PFC laboratory testing and conditioning protocols to simulate field performance. These protocols are intended to be used in forensic analysis and to evaluate PFC mix design procedures. Morphological and physiochemical properties of asphalt mixture component materials were examined to reveal the component materials propensity for moisture susceptibility. Volumetrics, binder stiffness, aggregate morpholgy, and surface energy were evaluated. Compacted specimens of six asphalt mixtures were tested using the Hamburg-Wheel Tracking Test and a single conditioning protocol was used to evaluate the effect of moisture conditioning on IDT strength and Cantabro Loss. Test results were compared to previous observations of the field performance of laboratory mixtures to validate the testing and conditioning protocols. High variability of test results led to only one test, the Cantabro Loss test, being recommended to predict field performance. A laboratoryconditioning protocol was not recommended as the experimental protocol did not induce sufficient moisture damage to significantly impact test results.