Experimental Study on the Thermal Damage Characteristics of Limestone and Underlying Mechanism

This work discusses an experimental investigation on the thermal damage characteristics of limestone and underlying mechanism. Cylindrical rock samples were heated to a specific temperature level of 25, 100, 200, 300, 400, 500, 600, 700, 800, and 900 °C. Then the thermal damage evolution equation was established based on the experimental results and the characteristics of thermal damage were analyzed. Last, possible mechanisms for the observed thermo-physical and mechanical response are discussed. The results show that with the increase of temperature in the tested range of temperature, the P-wave velocity, peak compressive strength and elastic modulus decrease, but the peak strain increases; the damage factors increase faster in 200–600 °C; the development of high-temperature-induced cracks conforms to the dislocation theory; the decomposition of magnesium carbonate and dolomite is the main reaction in the tested temperature range.