Abstract:The mechanical properties of coarse sandstone specimens such as longitudinal wave velocity,compressive strength,average and deformation moduli,peak strain are studied under uniaxial compression after being heated to different temperatures(100 ℃–900 ℃). The servo-controlled testing machine RMT–150B is adopted to conduct the experiments. Though the experimental results are discrete,the general law is obvious. The longitudinal wave velocity of specimens changes little below 100 ℃ and declines linearly with the increase of temperature when the temperature exceeds 100 ℃. The compressive strength and average modulus of sandstone increase slightly when the temperature ranges from 100 ℃ to 500 ℃,while the deformation modulus has a slightly decrease. When the temperature exceeds 500 ℃,the compressive strength,average modulus,deformation modulus have a little decrease,while the peak strain increases slightly. The experimental results also demonstrate that the temperature has two different effects on the mechanical properties of sandstone. On the one hand,high temperature can induce deformation,making some pre-existing fissures close and improving the degree of density;the contact state of mineral grain in sandstone and the friction character are improved;and the bearing capacity and non- deformability of samples are enhanced. On the other hand,different thermal expansion coefficients can induce the incoordinate thermal stress between different grains;and then the new tiny crack produces in the specimens. In the meantime,the stiffness of cemented material decreases,so the bearing capacity and non-deformability of sandstone specimen are weakened.