Modeling the mechanical behavior of cement stabilized macadam with defects based on particle flow theory

Abstract

Abstract The material of cement stabilized macadam is a discontinuous, inhomogeneous and quasi-brittle material. When it is locally damaged, it will be very limited to analyze the crack propagation and stress transfer with the theory of homogeneity and continuum. In order to study the meso-mechanical properties of cement stabilized macadam, a discrete element model of cement stabilized macadam was constructed in this paper by random theory according to the gradation and porosity of the laboratory material. The linear bond contact model, parallel bond contact model and smooth joint contact model were used between aggregates. Pre-added cracks of a certain density and width are set up separately in the interior of the discrete element model. The mechanical behavior of cement stabilized macadam under external loads was studied. The results show that: The data of discrete element model is highly justified by the stress-strain curves and the distribution of micro-cracks. The peak stress gradually decreases as the density of pre-added cracks increases. The peak stress for a crack density of 0m/m2 is 45.3%, 67.7%, 77.4% and 84.2% greater than that of 20m/m2, 30m/m2, 40m/m2 and 60m/m2 respectively. The stress peak for pre-added cracks with a width of 0 mm is 13.3%, 20.1% and 27.7% greater than that of 0.15 mm, 0.3 mm and 0.43 mm respectively. Most of the breakage cracks extend in the direction of the pre-added cracks. The angle of the broken cracks is predominantly 70° − 110°, accounting for about 45%.