Meso-damage behaviour of cement-stabilised macadam after long-time immersion based on particle flow theory

Abstract

Water can cause a certain degree of damage to cement-stabilised macadam (CSM), and the degree of damage is greater if CSM is immersed in water for a long time. In order to study CSM damage after lengthy water immersion, a discrete-element model of CSM was established. The Weibull distribution function was used to simulate the heterogeneous contacts between particles. The parallel bond model was used to simulate the material constitutive relationship. The microscopic parameters of CSM were obtained by trial-and-error method. The stress–strain curve was obtained from immersion tests. The micromechanical behaviour of the CSM after immersion was analysed. The results showed that the contact area and strength of the CSM immersed for 30 days were, respectively, 31.4% and 46% less than those of the non-immersed macadam. The force chains between particles were evenly distributed. At peak loading, the normal contact force between particles was much larger than the tangential contact force, and the vertical force chain was much larger than the transverse force chain. The distributions of cementation energy, friction energy and impact energy were not uniform in the middle/peak loading stage.