Research on the permanent deformation mechanism and dynamic meso-mechanical response of porous asphalt mixture composite structure using the discrete element method

Abstract

This study proposed a heterogeneous 3D virtual rutting model to investigate the rutting evolution mechanism and the dynamic meso-mechanical response of a porous asphalt mixture composite structure. The 3D virtual rutting test model incorporated a three-phase asphalt mastic-aggregate-airvoids system with grain size distribution and genuine aggregate morphology. Innovative algorithms were developed for cyclic rolling loading to reflect repetitive wheel loading. In contrast to the indoor rutting tests, the 3D virtual rutting tests exhibited greater rutting deformation and weaker dynamic stability in the range of 3.16%–10.17% and 2.65%–11.77%, respectively. Shear forces were predominant in the virtual rutting tests. As the porous asphalt mixture composite structure's surface layer thickness increased, the shear contact force increased and the maximum parallel-bond (PB) contact force diminished. The 3D virtual rutting test model was demonstrated to be feasible for simulating rutting deformation and dynamic meso-structural responses in porous asphalt mixtures with cyclic rolling loading algorithms.