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Abstract The change of rock internal microstructure along with temperature increasing leads to the variation of physico-mechanical properties. The experiments on physico-mechanical properties evolution of granite were carried out at temperature ranging from room temperature to 800 ℃ by using MTS servo-controlled testing machine and heating furnace. The research results indicate that：(1) The rock physico-mechanical properties change with temperature can be divided into five stages：i.e. room temperature to 100 ℃，100 ℃ to 300 ℃，300 ℃ to 500 ℃，500 ℃ to 600 ℃ and 600 ℃ to 800 ℃. The first three stages of temperature range correspond to the vaporization escaping interval of adhered water，and bound water and structural water. (2) The phsyico-mechanical parameters of rock have larger changes in temperature between 400 ℃ to 600 ℃，specially at the temperature of 573 ℃，where quartz has a phase transformation，from α phase to β phase. In this process，it is leaded to the increase of rock internal microcracks，which can be described as increasing of volume，reducing of bearing capacity，increasing of permeability，and the mutation of wave velocity. (3) After the temperature higher than 600 ℃，rock strength and wave velocity continue to reduce，which is influenced by solid mineral inflation and fracture of metallic bonding.
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Received: 13 November 2012
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2013, Vol. 32 
