Extended finite-element modelling of asphalt mixtures fracture properties using the semi-circular bending test

The semi-circular bending (SCB) test is becoming a more popular candidate for measuring asphalt mixtures fracture properties. It is a simple and inexpensive test, the sample preparation is straightforward, and the mode of failure in SCB samples is due to tensile stress induced by bending. The objective of this study is to investigate the feasibility of using the SCB test to quantify asphalt mixture fracture properties. Seven asphalt mixtures were tested in the laboratory. Part of the experimental program results were used to develop and calibrate an extended finite-element model (XFEM) coupled with cohesive zone modelling (CZM). The XFEM-CZM model was then used to investigate crack propagation in SCB and to predict SCB simulations for experimental results not used in the calibration process. The model calibration had a very good agreement with the experimental results and the model successfully predicted the SCB testing results. Based on XFEM-CZM results, the crack propagation in SCB is mainly attributed to tensile stresses.