3D Mesomechanical Simulation–Based Approach to Determining Representative Volume Element of Asphalt Concrete

This study proposes a three-dimensional (3D) mesomechanical simulation–based approach to determining the representative volume element (RVE) of asphalt concrete. In this approach, 3D mesostructures of asphalt concrete were developed by parametrically modeling the morphological characteristics of coarse aggregates and air voids. To define the RVEs, the effects were assessed of several geometrical characteristics, such as the volume fraction, gradation, and spatial distribution of coarse aggregates in the mesostructures. Further, the geometrically defined RVE was verified by performing finite-element simulations and inspecting whether the effective mechanical properties of asphalt concrete, such as the viscoelastic dynamic modulus, were accurately simulated. This approach was applied to a typical dense-graded asphalt concrete with a nominal maximum aggregate size of 13.2 mm. The results indicate that the proposed approach can effectively define the RVE of the asphalt concrete, of which the effective properties can be precisely simulated from the RVEs with a size of 50 mm. In addition, in terms of accurately characterizing the dynamic modulus only, an RVE size of 45 mm can satisfy the requirement. Findings of this paper are consistent with the results of existing RVE studies performed based on the laboratory tests. Therefore, the proposed approach provides a novel simulation-based paradigm for efficiently defining the 3D RVEs of asphalt concrete in mesoscale/multiscale simulations.