Experimental study on the mechanical properties of rocks at high temperature

The mechanical properties of marble, limestone, and sandstone as well as the stress-strain curve, the varying characteristics of the peak strength, the peak strain and elastic modulus were studied by using the MTS810 Rock Mechanics Servo-controlled Testing System under the action of temperatures ranging from room temperature to 800°C Results show that (1) the peak strength and elastic modulus of marble fluctuate at the temperature from normal to 400°C; and they decrease gradually over 400°C (2) With the rise of the temperature, the peak strength and elastic modulus of limestone show downward trend from normal temperature to 200°C have little change from 200°C to 600°C and decrease sharply over 600°C (3) The peak strength of sandstone shows a downward trend while a little change for elastic modulus at normal temperature to 200°C and from 200°C to 600°C, the peak strength of sandstone increases while a little change for elastic modulus; the peak strength and elastic modulus decrease rapidly at the temperature over 600°C. (4) The peak strain of limestone shows little change at normal temperature to 600°C, however, the peak strain increases rapidly over 600°C; and for marble and sandstone, the peak strain decreases with the rise of the temperature from normal temperature to 200°C, the peak strain increases rapidly over 200°C. The result can provide valuable references for the rock engineering design at high temperature.