Study on the rubber-modified asphalt mixtures' cracking propagation using the extended finite element method

Crumb rubber modified (CRM) asphalt mixtures have been widely used in highway asphalt pavement due to its environmental advantages and enhancement of mechanical performance. Numerical simulation analysis on rubber-modified asphalt mixtures' crack propagation has attracted more attention when characterizing the low temperature performance of asphalt pavement in recent years. However, in past numerical simulation processing, most researchers took the rubber-modified asphalt mixtures as a linear elastic material, which is incompatible with the viscoelastic characteristics of the rubber-modified asphalt mixtures. Thus, it cannot fundamentally evaluate the fracture characteristics of the rubber-modified asphalt mixtures. Based on this, viscoelastic mechanism of the rubber-modified asphalt mixtures are considered in this paper. The paper studied simulation of the rubber-modified asphalt mixtures crack growth using Extended Finite Element Method (XFEM), based on the notched semi-circular bending (SCB) test. This study investigated the stress distribution characteristics during the crack growth, the path of the crack growth, and the effect on the rubber-modified asphalt mixtures' fracture characteristics using the different rubber content. Thus, it can provide a theoretical guide for the forecast and control of the fracture damage caused by crack growth, which is one of the main early distresses of rubber-modified asphalt pavements.