Mechanistic Analysis of Asphalt Pavements, Using Superpave Shear Tester and Hamburg Wheel-Tracking Device

Abstract

A comparative evaluation of permanent deformation and moisture damage of asphalt mixtures using the Superpave shear tester and the Hamburg wheel-tracking device (HWTD) is presented. The damage analysis of simulated asphalt pavements is also included. The selected materials were a PG 64-22 asphalt binder and a sandstone aggregate with and without an antistripping additive. The repeated shear at constant height (RSCH) and HWTD tests were performed for the evaluation of permanent deformation. The results showed that the Superpave mixtures were less susceptible to permanent deformation than the Marshall mixture. The results of the HWTD tests performed at 40°C were consistent with those of the RSCH tests. Two permanent deformation models were compared to relate plastic strain accumulation with the number of load repetitions. The one selected for use in the Strategic Highway Research Program A-005 contract is generally better than the other model. For moisture susceptibility evaluation of these mixtures, the results of the AASHTO T283 tests were consistent with those of the HWTD tests at 40°C. The creep compliances calculated from the frequency sweep at constant height tests were applied to the KENLAYER program for pavement damage analysis. On the basis of the data analyses in this study, the simulated asphalt pavements are considered more of a material and mix design problem than a structural problem. The use of creep compliances of the above mixtures could not successfully predict the pavement performance in comparison with results of the RSCH and HWTD tests.

Uniaxial Penetration Testing for Shear Resistance of Hot-Mix Asphalt Mixtures

“…Common laboratory procedures to evaluate the rut resistance of HMA mixtures include the simulative wheel-tracking tests (such as the asphalt pavement analyzer and the Hamburg and French wheeltracking testers) and axial creep mode tests (such as flow number and flow time in the uniaxial or triaxial mode) (6)(7)(8)(9)(10)(11)(12). However, all of these procedures either require sophisticated equipment or usually take a long time to finish, thus making them difficult to implement into HMA mix design, field quality control-quality assurance procedures, or both.…”