Shear fatigue between asphalt pavement layers and its application in design

Abstract The performance and usable life of an asphalt pavement mainly depend on the interlayer bonding state. To design an asphalt pavement, tensile fatigue stress of the asphalt layer and permanent deformation of the asphalt surface are commonly used as the design criteria in many countries. However, the shear fatigue damage at the interface of asphalt pavement layers is usually neglected; therefore, the study of shear fatigue in the interface of asphalt pavement layers and its application in design has some theoretical and practical importance. Based on the indoor shear fatigue test carried out using tack coat materials, in this study, the shear fatigue formula and prediction models of indoor shear fatigue life were established and modified as per the engineering experience and actual working conditions of tack coat materials in the asphalt pavement structure. Based on the material’s shear fatigue failure at the interface of asphalt pavement layers, an interlayer design method for asphalt pavement was proposed. Using the traditional design method for asphalt pavement in China, the shear fatigue formula and prediction models were applied in the design example, and the results show that it is a rational approach. The results of this study provide a quantitative reference for the design of an asphalt pavement.