A Comparison of Two-Dimensional and Three-Dimensional Micromechanical Discrete Element Modeling of the Splitting Tests for Asphalt Mixtures

Simulation is an important approach for predicting the physical properties of asphalt mixtures. However, the simulation results are usually perfect because the model parameters or material properties were generally obtained by reverse modeling, and it is difficult to find the problems in simulation and distinguish superiority and inferiority of models by the results. Based on imaging and discrete element method (DEM), this study aims to compare two-dimensional (2D) and three-dimensional (3D) micromechanical modeling of the splitting tests for asphalt mixtures. The 2D and 3D microstructure-based discrete element models of a splitting test were established by a discrete element program called Particle Flow Code in Two/Three Dimensions (PFC2D/3D). The strengths and stresses at low temperatures were numerically simulated based on these models. The obtained results were compared, and then verified by an actual splitting test. Results reveal that the 3D discrete element simulations are more stable and more reliable than the 2D discrete element simulations.