A numerical study on the effect of aggregate gradation on mechanical response of asphalt mix

Various aggregate gradations are recommended in various guidelines/specifications for different types of asphalt mixes. These aggregate gradations have primarily evolved through experimental studies and experience on their field performances. Given a size range of aggregates, numerous aggregate gradations (and thereby numerous asphalt mixes) are possible. It is essentially a cumbersome and time consuming task to study the laboratory or field performances for all such possible asphalt mixes. The objective of the present work is to perform a micromechanical analyses on various asphalt mixes generated from computer simulated aggregate gradations. A hierarchical modeling scheme is used in the present work, where the asphalt mix is modeled as elastic-visco-plastic matrix with aggregates as rigid particulate intrusions with large volume fraction. In this process, a large number mixes can be simulated for their mechanical responses and some of them can be chosen for further laboratory verification. It is expected that such a process would save a considerable time and effort while finalizing a suitable gradation for the mix design.