Interface effects on the creep characteristics of asphalt concrete

A micromechanical creep model is presented to predict the creep behavior of asphalt concrete (AC) and investigate the effect of imperfect interface between asphalt mastic and aggregates on the viscoelastic properties of AC. The linear spring layer model is introduced to characterize the interface imperfection. Based on the modified Mori-Tanaka method, the micromechanical model is developed. To describe the viscoelastic properties of AC with imperfect interface, micromechanical creep compliance formulation is obtained by incorporating the elastic-viscoelastic correspondence principle. The present prediction is compared with available experimental data in the literature to verify the proposed method. It is found that the micromechanical creep model has the capability to predict the creep behavior of AC. Interface effects on the creep behavior of AC are explored using the developed model. It is concluded that the imperfect interface between asphalt mastic and aggregates has a significant influence on the overall mechanical behavior of AC, and that the interfacial damage should be controlled within a certain extent.