Micro-macro performance evolution behavior of fine-grained porous asphalt mixture exposed to ultraviolet-water-heat-load coupling action

In the Yangtze River Delta of China, porous asphalt pavement is significantly affected by UV radiation, water, heat, and traffic load. Therefore, research on its long-term performance evolution behavior under multi -factor coupling effect contributes to conducting engineering practice. The key pavement performance evolution of fine-grained porous asphalt mixture (PA -13), using SBS/crumb rubber (CR) composite modifier or TPS modifier, with multiple void ratios was studied. The evolution of high-temperature stability, water stability, and mesodrainage performance of PA -13, among the simulated 5-year service process, was respectively evaluated by dynamic creep test, immersion Marshall test, CT scanning and three-dimensional reconstruction. The findings demonstrate that the negative impacts of coupled conditions are mainly concentrated in the later stage of service. Under cyclic effect, the good anti-permanent deformation ability of SBS/CR PA -13 helps to alleviate the attenuation of its void structure and permeability. Besides, the transverse connectivity of void is more obvious than the vertical connectivity throughout the entire service process. In general, SBS / CR PA -13 has better antiattenuation ability than TPS PA -13 in high temperature stability, water stability and drainage performance, indicating SBS/CR porous asphalt mixture is more suitable for application in high temperature and rainy areas.