Macro and micro mechanics behavior of granite after heat treatment by cluster model in particle flow code

In this paper, a cluster model in particle flow code was used to simulate granite specimens after heat treatment under uniaxial compression. The results demonstrated that micro-cracks are randomly distributed in the specimen when the temperature is below 300 \({^{\circ }}\)C, and have partial coalescence when the temperature is up to 450 \({^{\circ }}\)C, then form macro-cracks when the temperature is above 600 \({^{\circ }}\)C. There is more inter-granular cracking than intra-granular cracking, and their ratio increases with increasing temperature. The micro-cracks are almost constant when the temperature decreases from 900 \({^{\circ }}\)C to room temperature, except for quartz \(\alpha \)–\(\beta \) phase transition temperature (573 \({^{\circ }}\)C). The fracture evolution process is obviously affected by these cracks, especially at 600–900 \({^{\circ }}\)C. Elevated temperature leads to easily developed displacement between the grains, and the capacity to store strain energy becomes weaker, corresponding to the plasticity of granite after heat treatment.