High Temperature Performance of Rubber-Modified Asphalt Mixtures in Water-Light-Heat Coupled Environment

Abstract

Asphalt pavement has been repeatedly subjected to vehicle loads during service. The probability and risk of water damage and asphalt deterioration of asphalt pavements is relatively higher in high temperature and rainy areas such as the Guangxi region of China. In this paper, the changes in rubbermodified asphalt and its mixtures under high temperature, water cycling, and ultraviolet light have been investigated. The coupled water-light-heat effects on asphalt pavements were simulated by developing a freeze-thaw cycle test protocol and a UV environment simulator. The high temperature performance of asphalt and asphalt mixtures before and after aging was compared and statistically analyzed by indoor tests of needle penetration, ductility, softening point, rutting factor and dynamic stability. Under water-light-heat coupling, rubberized asphalt showed a deeper degree of aging, accelerated conversion of asphalt to a highly elastic material, and an increased tendency to reduce flow capacity. The results showed decreasing dynamic stability of rubberized asphalt mixtures with decreasing needle penetration and ductility, increasing softening point, increasing rutting factor and decreasing phase angle. The effect of UV light on asphalt needle penetration was more significant, while the number of freeze-thaw cycles had a more pronounced effect on softening point.