Investigation of the fracture properties of asphalt mixtures with different notch depths at intermediate temperatures: Finite element approach

Abstract

Recently, researchers have focused on investigating various properties of asphalt mixtures using finite element method. Thanks to this method, it is possible to simulate performance tests in the laboratory and get very similar results. In this study, semi-circular asphalt mixture samples were obtained in the laboratory, and then subjected to the Semi- Circular Bending (SCB) test to determine the fracture parameters. With the help of the finite element software, 2D asphalt mixture samples were created with five different notch depths of 1 cm, 1.5 cm, 2 cm, 2.5 cm, and 3 cm. The effect of notch depth on the fracture properties of asphalt mixtures was evaluated by simulating the SCB test at five different displacement rates 0.1, 0.5, 1, 5, and 10 mm/min. The results showed that the maximum load and fracture energy values decreased as the notch depth increased. Furthermore, the cracking strength of asphalt mixtures was calculated by using the elastic-plastic fracture mechanics approach (J-integral). Finally, Response Surface Methodology (RSM) analysis was performed to determine the degree of impact of the different variables on the results. Consequently, the notch depth was more significant than the displacement rate.