A numerical study on mechanical performance of asphalt mixture using a meso-scale finite element model

Abstract

This paper concerns with meso-scale finite element (FE) modeling of asphalt mixtures. The proposed FE model is capable of simulating the complex geometry of several types of asphalt mixture in which different gradations of aggregates could be properly modeled. The meso-structure of the mixture is constructed by a novel technique identified in this paper. The main idea of such technique is that the aggregate particles could be randomly packed together into the simulation region, by defining a kind of artificial interaction forces among the particles. After that by the Voronoi tessellation method, the set of the generated discrete grains will alter to space-filling, adjoining polyhedrons with respect to the real geometry so that it were possible to investigate the behavior of mixture by finite element method. Such a model considers the main components of the asphalt mixture consisting of aggregate particles, mastic, interfacial zone and air voids. Moreover, different moving wheel loads with different passing velocities are considered and their effects on the mechanical responses of the asphalt mixture are examined. The FE model gives some better insights into the behavior of mixture's components under moving loads. The responses include vertical displacement of the pavement surface as well as the development of stress in mixture components. The proposed models give results that are in agreement with theoretical predictions and previous studies.