Under uniaxial compressive and tensile loading

limestone’s meso-structure has been investigated by real-time under high temperature with advanced experiment instruments such as High Temperature Fatigue Testing System with Scanning Electron Microscope in Tsinghua University. Thermal damage evolution process

thermal crack growth and fracture characteristic of rock are discussed. The damage model of rock thermal crack growth is established. Combining test results with the concept of dislocation and diffusion creep

thermal damage deformation fracture mechanism of rock are researched. The results show that the thermal crack is intercrystalline crack mainly within the scope of 500 ℃.