Simulation of the asymptotic behaviour of bituminous mixtures using the discrete element method

Abstract

Use of the Discrete Element Method (DEM) to simulate the asymptotic elastic behaviours of bituminous mixtures (low-temperature-high-frequency or high-temperature-low-frequency) is investigated. Aggregates are represented in the numerical specimen by 10,000 spherical particles, with size distribution according to the grading curve of the reference material (the French GB3 bituminous mixture). Aggregates below 1 mm and bitumen are considered in the mastic phase, represented through interaction laws between particles. The preparation procedure of the numerical specimens ensures isotropy and enables detection of the networks of direct (contact) interactions between aggregates and of interactions via the mastic interface. Normal and tangential elastic interaction laws were used for the simulation of the asymptotic behaviours. Several numerical tests were performed to assess the capability of the discrete model to reproduce the asymptotic behaviours of the reference material in terms of complex Young’s modulus and complex Poisson’s ratio.