Anti-skid durability of porous drainage asphalt mixture based on discrete element

Abstract

Since late 20th century, China’s expressway construction has developed rapidly, and the mileage of expressways has become the world's first. However, the safety indicators of expressways, including skid-resistance and durability, decline with time. Public roads that have been in use for an extended period possess a higher level of danger to some extent. In order to improve the safety indicators such as skid-resistance and durability of the road, the discrete element method (DEM) is used to study the proportion of the asphalt mixture, and the spatial structure of the coarse aggregates and asphalt mortar are compared and analyzed. Relevant models are established to compare their pendulum values and structure-depth attenuation. The simulation results show that when the mixture ratio changes, the pendulum value also changes accordingly. When limestone replaces the fine aggregate in the andesite, its pendulum value is increased by 1.5%. When the fine aggregate is limestone and the surface polishing times do not exceed 3500 times, the 7/3S1 asphalt mixture has the best pendulum value. However, as the polishing times continue to increase, the mixture ratio also changes. Compared with the 7/3S1 asphalt mixture, the 8/2S1 asphalt mixture has better effect. When the fine aggregate is replaced by limestone, no matter what form the coarse aggregate is, the pendulum value has been improved to a certain extent comparing with the previous mixture. A2 S2, 5/5S2, 7/3S2 and 8/2S2 blends, compared with A2 A2, 5/5A2, 7/3A2 and 8/2A2 blends, the pendulum value was increased by 1.7 %, 0.5 %, 2.3 %, and 2.1 % respectively. The study shows that in different proportions of coarse aggregates, as the surface texture richness of the blended aggregate increases, the differences between the aggregates also increases, and skid-resistance and durability are also enhanced. The research results provide a blending method to increase the skid resistance and durability of asphalt pavement.