Quantitative analysis of the role of temperature in the mesoscale damage process of semi flexible pavement composite through finite element method

Poor cracking resistance is a widely known concern of semi-flexible pavement (SFP). However, most of the previous studies on SFP composite have focused on the crack evolution at the macroscale, while the corresponding studies on the mesoscopic damage process are very limited. Moreover, the cracking resistance of SFP composite was found to be significantly affected by temperature, but quantitative analysis on such effect is missing. To fill the knowledge gap, this study aims to understand the role of temperature on the mesoscale damage process of SFP composite using the finite element method (FEM). The cohesive elements for the asphalt binder and cement grout phases, and the adhesive element along the interface between asphalt and aggregate and along the interface between asphalt and cement grout were considered in the simulation process. An equivalent dynamic modulus of asphalt binder was also introduced to incorporate the interlocking effect in the analysis process. Similarly, the pull-off test was performed to incorporate the role of interface strength in the damage process. The change in the roles of different phases (asphalt binder or cement grout) and interfaces (cement grout-asphalt binder or asphalt binder-aggregate) in SFP composite in the damage evolution process with the change of temperature was clearly identified. Overall, this research is a steppingstone towards better understanding of the cracking mechanism of SFP at the mesoscale, which can help develop SFP composite with improved cracking resistance.