Evaluation of interlayer stability in asphalt pavements based on shear fatigue property

Abstract

Interlayer fatigue resistance is an important property to ensure the durability and stability of asphalt pavements. Shear fatigue damage is one of the main failure modes of asphalt pavements, but the existing design methods involve little in the way of shear fatigue property. In this work, the fatigue life of five different interlayer bonding conditions was studied by a direct shear fatigue test. The fatigue test data was processed by the Weibull distribution function. The laboratory prediction model of interlayer fatigue life was obtained with shear stress (τ) and interface stiffness (Kmin) as variables. A decay model of interlayer bonding property was proposed based on the fatigue life model. The axle-load conversion formula was obtained based on the laboratory prediction and decay models. The laboratory fatigue life prediction model was revised, and the final prediction model was obtained. Finally, a method to evaluate interlayer stability was proposed based on the shear fatigue model and conversion method of axle-load. The study provides a theoretical basis for the interlayer design and stability evaluation of asphalt pavement.