Mesomechanical modeling of asphalt concrete considering full aggregate size range and conjunctive shell mechanism of interface transition zones

Existing mesostructural modeling methods for asphalt concrete mostly simulate coarse aggregates only and treat fine aggregates as part of the homogenized asphalt mortar matrix, thus offering a narrow perspective into the mesomechanical behavior of asphalt concrete and potentially misinterpreting the actual mesomechanisms. To overcome these deficiencies, the current modeling methodology needs a breakthrough in allowing for the presence of a full size range of aggregates and the interface transition zones (ITZs). To this end, this study proposed a Voronoi-mesh based (VMB) mesostructural modeling approach, which first generates relatively large aggregates via a Voronoi technique and then meshes the residual model space into remaining size ranges of aggregates, ITZs and asphalt mastic. A conjunctive shell mechanism was proposed to account for the overlapped ITZs induced solidifying reinforcement effects. The proposed mesomechanical modeling method was validated via complex modulus tests. Mechanisms of solidifying reinforcement and load transfer in asphalt concrete were revealed.