Performance changes of hot recycled asphalt mixture in different layers under coupling of multiple aging factors

Abstract A climate simulation test system (CSTS) was developed to couple the aging factors including light, heat, oxygen and moisture. In the paper, 16 kinds of hot recycled asphalt mixtures modified by 3.5 wt‰ granular polymer reinforcing agent (GPR) were obtained and the pavement performances (high temperature performance, low temperature performance, water stability and fatigue resistance) of them were tested. The results indicated that the aging had a negative impact on the low temperature performance and fatigue resistance of the hot recycled asphalt mixture, especially after 30 days of long-term aging, the low temperature performance of the hot recycled asphalt mixture decreased obviously. However, the water stability of hot recycled asphalt mixture had a peak value with aging time. Besides, in the early and middle stage of long-term aging, GPR could significantly improve the pavement performances of hot recycled asphalt mixture.