A framework for estimating the fracture resistance of hot mix asphalt using an energy approach

Abstract

This study developed a novel approach to evaluating the fracture resistance of HMA under the monotonic loading and the fatigue loading at the low and intermediate temperatures. In the monotonic loading test, the dissipated energy is divided into three parts: the plastic strain energy, the elastic strain energy, and the surface energy. In the fatigue loading test, fatigue life, dissipated energy in each cycle, the cumulative dissipated energy, and damage factor were used to analyze the fracture behaviors of HMA. In the monotonic test, a lower temperature or a greater notch depth could induce an earlier crack initiation. At −10 °C and 0 °C, the elastic strain energy absorbed before cracking was greater than the plastic strain energy. When the temperature increased to 25 °C, the plastic strain energy increased remarkably. For all the specimens, most of the external energy was converted to surface energy and then consumed by the crack propagation. Under the effect of tensile fatigue, the hysteresis loop under different stress ratios all showed loose - dense - loose behaviors. High stress ratios showed a greater growth rate of the cumulative dissipation energy, which indicated a faster accumulation of fatigue damage.