Evaluation of deformation response of HMA under APT and wheel tracking tests

Abstract

This paper is based on a study into the rutting performance of HMA which forms part of the larger research initiative. The objective of this phase is to identify and develop appropriate test protocols and associated acceptance criteria for the assessment of rut resistance of hot mix asphalt(HMA). A road test section, surfaced with a standard continuously graded medium HMA material, was subjected to full scale Heavy Vehicle Simulator (HVS) and scaled Model Mobile Load Simulator (MMLS) testing. A laboratory test program to characterize the material was conducted as well. This paper contains a comparison between the Accelerated Pavement Testing (APT) in the field and wheel tracking tests performed as part of the laboratory study (Hamburg Wheel Tracking Tests and Transportek Wheel Tracking Test). The method of analysis of the creep curves is presented as well as the method used for comparing measured permanent deformation with mechanistically determined elastic strain values. The average elastic shear strain at the edge of the tire over the full thickness of the HMA layer was found to be the best indicator of plastic deformation potential at different temperatures