Fatigue cracking performance evaluation of laboratory-produced polymer modified asphalt mixture containing reclaimed asphalt pavement material

Abstract

This study investigated the effect of reclaimed asphalt pavement (RAP) on the rheological properties of a polymer modified binder and the fatigue cracking performance of polymer modified asphalt mixture. Performance grading, master stiffness curve and black space analysis were conducted on the asphalt binders at different laboratory ageing conditions. The repeated loading semi-circular (R-SCB) test was conducted on the mixtures. Test results of the asphalt binder showed that the addition of RAP increased the stiffness and the Glove-Rowe (G-R) Parameter value of asphalt binder. Higher RAP binder could be susceptible to non-load-associated cracking after long-term ageing or in a cold climate as binders with more than 30% RAP after the PAV 40 h ageing condition had a G-R value greater than 180 kPa. The fatigue damage in R-SCB test were analyzed by energy consumption approach and can be divided into three stages including the steady and cumulative damage stage and jump damage. The cumulative energy increased linearly with the loading cycles and the cumulative energy evolution meets Linear Miner’s Law in R-SCB test, then the average consumption per cycle (ECPCAVE) was selected as the index to evaluate the fatigue cracking performance of asphalt mixtures. It is found that higher ECPCAVE, faster cumulative rate of fatigue damage causing a lower fatigue life and poor fatigue cracking performance of asphalt mixtures. The addition of RAP contributed to the increase of ECPCAVE and the cumulative rate of fatigue damage. The higher RAP contents, the faster the cumulative rate of fatigue damage was, which caused smaller fatigue life. This paper suggests that ECPCAVE is a useful indicator to evaluate the fatigue cracking performance of asphalt mixture with and without RAP.