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 800A degrees C Results show that (1) the peak strength and elastic modulus of marble fluctuate at the temperature from normal to 400A degrees C; and they decrease gradually over 400A degrees C (2) With the rise of the temperature, the peak strength and elastic modulus of limestone show downward trend from normal temperature to 200A degrees C have little change from 200A degrees C to 600A degrees C and decrease sharply over 600A degrees C (3) The peak strength of sandstone shows a downward trend while a little change for elastic modulus at normal temperature to 200A degrees C and from 200A degrees C to 600A degrees 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 600A degrees C. (4) The peak strain of limestone shows little change at normal temperature to 600A degrees C, however, the peak strain increases rapidly over 600A degrees C; and for marble and sandstone, the peak strain decreases with the rise of the temperature from normal temperature to 200A degrees C, the peak strain increases rapidly over 200A degrees C. The result can provide valuable references for the rock engineering design at high temperature.