2D and 3D meso-scale finite element models for ravelling analysis of porous asphalt concrete

This paper presents 2D and 3D meso-level mechanical modelling for numerical analysis of ravelling resistance of porous asphalt concrete (PAC). The complex geometry of PAC was simplified so that the main components (aggregate particle, mortar, interfacial zone and air void) in the actual mixture were represented in the meso-scale model separately. Three different models, comprising 2D representations of different particle packing and 3D representations of the highest particle packing, were developed to gain insights into effects of geometric issues. Stress states linked to ravelling within bitumen-aggregate interfacial zones and mortar bridges were presented under moving wheel loads. In combination with computational results of 2D and 3D simulations insights into the correction error that follows from 2D representation were obtained. For the purpose of comparison, the relevant stress components were further transferred into various equivalent stresses using different failure criteria. Indicators including the stress/strength ratio and fatigue life were introduced to estimate the potential of material failures involved in grain contact region.