Effect of stone-on-stone contact on porous asphalt mixes: micromechanical analysis

Within the pavement engineering community, porous asphalt (PA) mixes are regarded as mixes capable of reducing noise and improving wet skid resistance. However, these mixes are likely to have the distress of ravelling. In order to analyse the propensity of a given PA mix for ravelling, the homogenisation technique can be considered as an attractive method. Along the line of the homogenisation technique, micromechanical models have been used to predict the stiffness of asphalt mixes. However, it was found that the predicted results were not in good agreement with the experimental values due to the fact that the stiffness of interacted aggregates was not accurately accounted in the models. To deal with this issue, it is important for researchers to study the stiffness of the interacted aggregates network and its role in the behaviour of a given mix. Based on this realisation, this paper provided a methodology to estimate the stiffness of the stone-on-stone skeleton and its role in the overall response of PA mixes. The results showed that the predicted stiffness of the stone-on-stone skeleton is dependent on the loading frequency/temperature and the compaction effort. The frequency response of the stone-on-stone skeleton is similar to that of the mix.