Three-dimensional fracture simulation of cold in-place recycling mixture using cohesive zone model

• The X-ray CT and DIP techniques were employed to create numerical model of CIR mixture.
• Cohesive zone model was utilized to simulate the fracture behaviour of CIR mixture.
• Numerical Arcan tests were carried out and compared to the experimental Arcan tests.

Cold in-place recycling (CIR) shows a good performance in the resistance to cracks in the field and a newly developed Arcan configuration has been used to investigate the Mixed-Mode cracking behaviour of CIR mixture. In this research, a three-dimensional (3D) heterogeneous fracture modeling method was presented to simulate complex cracking development in CIR mixture. The X-ray computed tomography (CT) technique and digital image processing (DIP) method were employed to create 3D heterogeneous numerical model of CIR mixture. In the modeling, a cohesive zone model (CZM) was utilized to estimate the crack resistance of the interface based on laboratory fracture test. The coalescence of micro-cracks and the inception and propagation of macro-cracks in CIR mixture were carefully studied under fracture Mode I and Mode II, respectively. The fracture process zone was also investigated. Three types of displacements, including the Load-Line Displacement (LLD), Crack Mouth Opening Displacement (CMOD), and Crack Tip Opening Displacement (CTOD) were utilized to plot load-displacement curves and the corresponding fracture energies were calculated. The analyzing results of virtual numerical test are proved to be quite consistent with the actual experimental test. The validity of numerical model is verified.