ABSTRACT
Aggregates account for most of the mixture’s weight and volume and, consequently, they play a key role in defining the overall mechanical response of these materials. In asphalt mixtures, the aggregate phase is composed of thousands of different discrete aggregates, each having a unique set of morphological properties that strongly contribute to the heterogeneity of the material. The objective of this work is to use a computational approach to study the isolated impact of the form and angularity of coarse aggregates on the linear viscoelastic material properties of an asphalt mixture, i.e. their axial Dynamic modulus (|E*|) and Phase angle (δ). To accomplish this goal, a recently developed Random Microstructure Generator was adapted and used to computationally produce two-dimensional microstructures of asphalt mixtures with coarse aggregates having controlled average values of Angularity and Form indexes (AI and FI, respectively). These microstructures were then implemented in Finite Elements (FE) and subjected to controlled—stress cyclic loading to determine |E*| and δ. In summary, the results show that variations in the morphology of the aggregates affect the overall contribution of the linear viscoelastic properties of the mixture, and they also impact the final variability of these parameters.
