Three-Dimensional Discrete Element Simulation of Asphalt Concrete Subjected to Haversine Loading An Application of the Frequency-Temperature Superposition Technique

Limited by the current computing power, it is impossible to simulate a full scale asphalt pavement with a three-dimensional (3D) microstructure-based discrete element (DE) model, when the time-dependent behaviors of the materials are considered. Researchers currently focus on modeling the microstructure of asphalt mixture materials and have not attempted pavement modeling. In addition, existing studies are limited to modeling asphalt mixtures without considering the time-dependent properties. In this paper, 3D DE models of asphalt mixtures under dynamic loads were developed with the assistance of X-ray Computed Tomography (X-ray CT). The time-dependent model was considered in the simulations. To shorten the computation, a frequency-temperature superposition technique was employed. Xray CT images were used to reconstruct the microstructure of asphalt concrete, while a time-dependent model was built by taking into consideration micro-scale interactions within the models. Through this study, it was observed that the dynamic modulus and phase angles of asphalt mixtures could be well-predicted from the component properties of those mixtures. It is anticipated that the techniques developed in this study can be used to simulate full scale pavements when the computation power is available.