Micro-cracking mechanism of cement stabilized macadam based on discrete element method

To investigate the micro-cracking evolution mechanism of cement stabilized macadam, a numerical model of mesoscale heterogeneous cement stabilized macadam was established. The microfracture network was introduced into the fine-scale inhomogeneous model and the relevant parameters were obtained using unconfined compressive strength tests. Then, the effect of different microfracture parameters on the micro-cracking degree was explored according to the displacement variation of particles in the model under vibration load. Finally, the energy evolution law of the system with different microfracture numbers was further analyzed. The results indicate that the numerical simulation results are in good agreement with the laboratory test results, the discrete element model of cement stabilized macadam can accurately characterize the mesoscopic failure characteristics of materials. Micro-cracking damage after the secondary vibration load together with the increase of microfracture width and microfracture number as a result. The microfracture density plays a decisive role in the degree of microcrack for cement stabilized macadam. With the increase of the microfracture number, the elastic strain energy storage capacity of the material decreases, and the total energy input of the cement stabilized macadam decreases. This study has proved that the positive effect of early micro-cracking on shrinkage stress reduction. In addition, the mechanical characteristics and fine mechanism of micro-cracking in cement stabilized macadam materials are revealed.