Effect of aggregate packing on open AC: Micromechanical analysis

Abstract

Within pavement engineering community, Open Graded (OG) mixes are regarded as mixes capable of reducing noise and improving wet skid resistance. Due to the formation of interconnected aggregate network, aggregate packing plays an important role in the overall response of OG mixes. However, some of the models developed in the past do not consider the effect of aggregate packing in their predictions which leads to unreliable predicted results. Thus, it is important to understand the contribution of packed aggregates in the prediction of mechanical properties of OG mixes. In this paper, a procedure for obtaining the stiffness of packed aggregates in OG mixes was proposed by mean of micromechanics (the Mori-Tanaka model) and it was verified on the basis of laboratory tests. The results showed that the calculated stiffness of packed aggregates is frequency dependent which needs to be considered in the prediction of mechanical properties of OG mixes.