Dynamic compression test has been performed on sandstones subjected to 800℃ based on split Hopkinson pressure bar (SHPB) and high-temperature furnace MTS652.02. We study the dynamic properties of sandstone specimens whose strain rate varies within the range between 17.904 s-1 and 62.600 s-1. The test results show that

after heated to 800 ℃

dynamic stress-strain curves of sandstone can be roughly divided into compaction phase

elastic deformation stage

microcracks evolution stage

crack unstable growth stage

strain softening stage and unload stage. With the increasing strain rate

the dynamic elastic modulus and peak stress of sandstone increase with logarithmic trend

while the peak strain decreases with a logarithmic form. The failure mode of sandstone is mainly typical tensile failure in low strain rate

while the proportion of shear fracture surface gradually increases as the increasing of strain rate; failure mode changes from tensile failure to shear failure. Undergoing 800℃ heat treatment，sandstone failure is gradually severe with the elevated strain rate

and the degree of failure is more significant sensitivity at high strain rates.