Effects of quenching cycle on tensile strength of granite

Quenching cycle has practical significance in the study of rock properties with regard to the cooling of the drilling fluid, development of geothermal resources and tunnel fire rescue. In this study, a Brazil splitting experiment was conducted with granite that is subjected to different temperatures up to 650°C and quenching times of 1–20. The results indicate that the tensile strength of granite is negatively correlated with the temperature and the number of quenching cycles. The tensile strength and wave velocity decrease as the temperature increases for the same quenching cycle. When the number of quenching cycles is >5, the influence of the number of quenching cycles on the tensile strength and wave velocity is relatively small. A faster rate of decline of tensile strength occurs at temperatures higher than 450°C. In addition, it is concluded that the changes in the tensile strength and wave velocity are similar for the tested temperature range and number of quenching cycles.