Semi-empirical method for the calculation of shear stress, stiffness and maximum shear strength of bituminous interfaces under in-service conditions

Abstract The structural response of a flexible pavement as a whole depends on the adherence between the bituminous layers, which are rarely found to be fully bonded or completely detached. In order to define the degree of bonding between the layers, the shear stiffness of the interface under in-service conditions is a fundamental property. The aim of this work is to propose a semi-empirical method based on laboratory test results for estimating the relative displacement speed between the sides of the interface, the shear stiffness, the shear stress and the shear strength from results of a direct shear test.