Mechanical behavior of asphalt mix: An experimental and numerical study

Asphalt mix is a composite material constituted with asphalt binder, stone aggregates and air voids. In this work a hierarchical approach is adopted for modelling asphalt mix behavior. Small size stone aggregates, asphalt binder and air voids, together, are assumed to behave like an effective homogeneous material and is termed as ‘binder mix’. The binder mix is modelled as an elastic–viscoplastic material. Asphalt mix is modelled as two phase material with a continuous phase (consisting of binder mix) and an explicitly represented dispersed phase (consisting of large elastic aggregates). The aggregates are simulated by generating non-overlapping ellipses of random shape and orientation. Samples with actual irregular shaped aggregates from experimental Marshall samples are as well considered. The overall behavior of the asphalt mix is studied by considering it to be an elastic–viscoplastic solid. The deformation of the asphalt mix is analysed with the finite element method allowing for large deformations. The numerical results are compared against experiments on line-loaded Marshall samples and observed to match well with experimental results.

► Asphalt mix is modelled as a two phase material.
► Continuous phase is binder mix and dispersed phase is large elastic aggregates.
► Hierarchical approach is adopted because a multitude of different length scales are involved.
► The predicted mechanical response of asphalt mix sample matches well with the experimental results.