Comparison of two criteria of stress intensity factor and fracture energy to investigate the behavior of asphalt mixtures under combined tensile-shear loading modes-A statistical approach

Abstract

Fracture energy and stress intensity factor are of the most prevalent criteria for determining the fracture behavior of asphalt mixtures. In this research, the fracture performance of asphalt mixtures under different modes of loading at different temperatures and loading rates was investigated, and the stress intensity factor and fracture energy were determined and compared to the fracture resistance criteria. For this purpose, loading modes of pure tension, pure shear and four different mixed shear-tension loading conditions were chosen, and the fracture tests were conducted on the SCB specimens at temperatures of −5 ℃, −15 ℃ and −25 ℃, loading rates of 1 and 5 mm/min and different loading modes. The results showed that the fracture behavior of asphalt mixtures is significantly dependent on testing temperature and loading rate. The studied parameters of fracture energy and stress intensity and the correlation between them are functions of the loading mode, loading speed, and testing temperature. Moreover, the changing trends of the parameters of fracture energy and stress intensity factor do not necessarily follow the same trend and each factor represents a specific concept of fracture performance of asphalt mixtures.