To investigate the effect of high temperature on physical and dynamic mechanical properties of limestone

basic physical tests were conducted on limestone specimens at room temperature and high temperature treatment from 100 ℃ to 800 ℃. Moreover

dynamic impact compression tests under the same loading conditions were also conducted using SHPB test device. Test results indicate that the main mineral composition of limestone is calcite and dolomite. At room temperature

the limestone has a compact structure. With the increase of treating temperature

the dolomite gradually decomposes into micro-sized particles

and the surface color of test specimens gradually changes from off-white to white. Moreover

the volume of test specimens increases

while its mass

density and P-wave velocity decrease. These variation rates are closely related to the temperature. Dynamic compression stress-strain curves of limestone specimens under different high temperatures are basically consistent. A small increase followed by a significant decrease can be observed for both the dynamic compressive strength and dynamic elastic modulus with the increase of the temperature. An obvious negative quadratic function relationship is also found between these dynamic parameters and the treating temperature

and the maximum value is observed at 200 ℃. However

parameters including the dynamic strain and strain rate of test specimens

and the treating temperature are in a positive quadratic function relationship. The failure modes of specimens transit from brittle to ductile brittle

and damage degree is the lowest at 200 ℃. The damage degree increases with the increase of temperature

and the size of limestone fragments gradually decreases

which basically becomes powder at 800 ℃.