Modulus prediction of asphalt concrete with imperfect bonding between aggregate–asphalt mastic

Asphalt concrete (AC) is a kind of complex multi-phase engineering material. To date, the evaluation and determination of mechanical behavior of AC remain resorting to experiments. However, this approach is not able to directly reveal the influence of the microstructure of AC quantitatively. In this paper, a micromechanics-based model is described to simulate the elastic behavior of AC, with the emphasis on the influence of the interfacial zone on the overall mechanical properties of AC. Tests on asphalt mixture with varying microstructures are conducted to verify the proposed model. The effect of key factors on the behavior of AC is investigated, including the modulus of asphalt mastic and coarse aggregate, air void fraction, aggregate gradations, the largest aggregate and interface between asphalt mastic and coarse aggregates. The outcome resulting from this paper can be applied to guiding the design efficiently to obtain different functional AC.