MECHANICAL PROPERTIES AND ACOUSTIC EMISSION RESPONSE OF GRANITE AFTER TREATMENT OF CYCLIC HIGH TEMPERATURE AND RAPID COOLING

Based on the consideration of the temperature and the number of cycles on the internal structure damage of the granite sample, we studied the mechanical properties and acoustic emission response characteristics of the granite after high temperature-rapid cooling cycles by the uniaxial compression test and the acoustic emission monitoring test. The results show the follows. As the temperature and number of cycles applied to the granite increase, the uniaxial compressive strength of the granite continued to decrease, and the peak strain corresponding to the uniaxial compressive strength increased accordingly. There was a clear difference in the intensity and distribution characteristics of the acoustic emission signal of granite between the normal temperature and the high temperature treatment. As the temperature applied to the granite increased, the maximum acoustic emission count rate and the cumulative ring count of the acoustic emission increased first and then decreased. With the increase of the number of heating-cooling cycles for granite, the maximum value of AE count rate and cumulative AE ring count tended to decrease, while the intensity of AE signal tended to increase.