Three-Dimensional Discrete-Element Modeling of Aggregate Homogeneity Influence on Indirect Tensile Strength of Asphalt Mixtures

Abstract

This study aims to investigate the influence of aggregate homogeneity on the indirect tensile (IDT) strength of asphalt mixtures using imaging and discrete-element method. An aggregate homogeneity index, which was used to assess the aggregate homogeneity in asphalt mixtures, was briefly described, and the aggregate homogeneities of different asphalt specimens were assessed by the index. A micromechanical model for predicting the IDT strength was established by a discrete-element program called Particle Flow Code in Three Dimensions. On the basis of this model and by loading asphalt specimens along different directions, the influence of aggregate homogeneity on the IDT strength at low temperatures was simulated; the simulation results were verified by an actual IDT test. Results show that the IDT strength exhibits anisotropy. There is no obvious correlation between the aggregate homogeneity and the IDT strength. However, there is an obvious correlation between the aggregate homogeneity and the variation in the IDT strength.