Influence of pore water phase change on service performance for permeable pavement in Sponge City

As the cornerstone of normal operation for Sponge City, the service performance of permeable pavement is directly related to the utilization rate of precipitation resources. However, the pore filling state (air, water and ice) of permeable pavement in Sponge City is easily affected by the service environment, especially low temperature. Thus, in the study, the influence of pore filling states and phase change processes on the service performance for permeable pavement were studied based on the models established on specimen section. Details of pore water phase change were visually displayed and described, and the strength variation of Marshall specimens after freeze-thaw cycle experiment also proved the rationality of simulation. Results show that the pore filling states in permeable pavement have different effects on the temperature field, and the influence of pore air on the temperature distribution for permeable pavement is greater than that of pore water (ice). In particular, weak positions between different pores are more susceptible to freezing stress, leading to stress concentration. Simulation results were also verified by macro experiments. Furthermore, the sustainable service performance of permeable pavement in Sponge City was inevitably affected. Therefore, the study results have certain significance for the development of permeable pavement in freezing and thawing regions, and are conducive to the wider application of Sponge City.