Discrete particle element analysis of aggregate interaction in granular mixes for asphalt: combined DEM and experimental study

The conventional approach to modeling asphaltic materials is to treat them at macro-scale using continuum-based methods. Numerous research works, however, show that for these mixtures it's very important to take into account their micromechanical behaviour, at the scale of aggregate particles, because it is a primary factor in terms of overall system performance. In this way the Distinct Particle Element Method (DEM) represents a very useful tool. In previous research works the authors have performed a DEM analysis of the fatigue performances of a road pavement and they have observed a great influence on the materials response of shape and interlocking of aggregates. In order to investigate this influence, a series of triaxial tests have been conducted and numerical results have been compared with the lab ones. The samples, in particular, are composed of different types of steel elements (spheres and angular grains), because this ideal granular material allows an accurate geometrical representation of physical test specimens to be made in DEM simulation.