关键词: 高温岩石, 遇水冷却, 物理特性, 力学特性, 扫描电镜(SEM)

Abstract: Laboratory tests are conducted to study the physico-mechanical properties of water cooling treated granite under room temperature to 500 ℃. Variations of physico-mechanical properties are analyzed in detail. Meanwhile, the physico-mechanical changing mechanisms of water cooling treated granite are revealed by the pictures of scanning electron microscope (SEM). The results show that: (1) The volume of the water cooling treated granite specimens under high temperature increases, while the mass and density decrease; for specimens treated at 500 ℃, the volume increases by 1.32%; the mass decreases by 0.21%; and the density decreases by 1.51%. (2) Longitudinal and transverse wave velocities of the water cooling treated granite both decrease; when temperature rises, and the decrease of longitudinal wave velocity is greater in rate than that of transverse wave velocity, when a granite specimen is heated to 500 ℃, longitudinal and transverse wave velocities decrease by 64.9% and 46.8%, respectively. (3) Uniaxial compressive strength and elastic modulus of water cooling treated granite decrease with temperature; and they decrease by 51.9% and 48.6% respectively at 500 ℃; the specimens show an obvious ductility characteristic when they are heated to 300 ℃. (4) The pictures of SEM show that many microcracks inside granite specimens are generated and extended after high-temperature treatment. With further increase of the temperature to 300 ℃, the quantity of microcracks rose gradually and the sizes of microcracks also increased gradually; and there will be a microcrack network appearing inside the granite specimen, causing deteriorations of physico-mechanical characteristics of water cooling treated granite.

Key words: heat-treated rock, water cooling, physico-mechanical properties, scanning electron microscope(SEM)