Simulation Analysis of Cement-Stabilized Macadam Compaction Processing Based on the Discrete Element Method

Abstract

The mechanical properties of cement-stabilized macadam (CSM) base mixture are closely related to its forming process. Although the present study investigates the macroscopic effects of molding on cement-stabilized macadam, mesoscopic research analyses of the internal composition’s structural characteristics and change trends after molding lack sufficient intuitiveness. In this study, we built three-dimensional models of cement-stabilized macadam for heavy compaction molding and vibration molding tests based on the discrete element theory. The effects of different molding methods on cement-stabilized macadam’s internal structure were revealed from the mesoscopic perspective by tracking changes in porosity, coordination number, force chain development and internal particle position during the simulation molding process. The simulation results show that (1) the first 10 compactions had a significant influence on the molding effect, and specimens’ height and porosity decreased the fastest; (2) after the simulation experiments, the average coordination number of particles in the vibration molding specimen was 2.3% higher than that of the heavy compaction molding specimen; (3) after the simulation experiments, the vibration molding specimen’s porosity was 2.5% lower than that of the heavy compaction molding specimen; and (4) the vibration molding specimen’s particle distribution was more uniform, whereas the heavy compaction molding specimen’s particle distribution was dense at the top and sparse at the bottom. Overall, the effect of vibration molding is superior to that of heavy compaction molding.