Dynamic Characteristics of Coarse Aggregates within Epoxy Asphalt Mixture during Superpave Gyratory Compaction

Abstract

Abstract To investigate the dynamic characteristic of coarse aggregates within epoxy asphalt mixture, this study conducted a virtual simulation of the Superpave gyratory compaction (SGC) test based on the discrete element method and artificial neural network. A three-dimensional compaction model of epoxy asphalt mixture was built and verified, considering the irregular polyhedral morphology and the elastic property of coarse aggregates, the mastic volume and the thermosetting and viscoelastic properties of epoxy asphalt mastic. Subsequently, the SGC numerical model was applied to analyze the particle velocity, porosity distribution, and particle force status at different compaction levels. Results demonstrate that the compactness increment mainly depends on the movement and rotation of aggregates in the early stage, and rotation of aggregates in the later stage. The existence of gyration angle and the internal structure of epoxy asphalt mixture can affect the dynamic behavior of aggregates. The structure of mixture in the central area is relatively more stable during compaction, and the peripheral area of the specimen is more difficult to compact.