Thermal Influence on Mechanical Properties of Granite: A Microcracking Perspective

The particle mechanics method is used to simulate the process of thermally induced micro- and macrocracks in granite, to elucidate the mechanisms responsible for temperature-dependent mechanical properties. The numerical results are quantified and compared with existing results from other experimental data in the literature. The results indicate that heating generally reduces the compressive and tensile strengths of granites, first because of increasing thermal stresses, and second because of the generation of tensile microcracks. Rock mechanical properties are reduced in specimens subjected to heating–cooling cycles, solely because of the increase in density of thermally induced tensile microcracks. The presence of a thermal gradient induces the formation of macrocracks, which propagate from relatively cool to relatively warm areas. It is also observed that the boundary condition of the specimen can also affect the development of microcracks.