STUDY ON FAILURE MECHANICAL BEHAVIOR OF MARBLE AFTER HIGH TEMPERATURE

Laboratory tests were made to study the mechanical properties of marble from room temperature of 800℃. The changes of peak intensity, peak strain,the modulus of elasticity, the modulus of the deformation and complete stress-stain curve of marble after high temperature were analyzed in detail. An acoustic emission instrument and a scanning electron tester were used at the same time. The failure law of marble after high temperature was studied. The results showed that the length and diameter of a marble specimen after high temperature increase, the mass and density decrease, but change little at 200℃ ; The mechanical properties of marble change little when the temperature keeps to 200℃; The peak intensity, the modulus of elasticity and deformation modulus of marble decrease and peak strain becomes large as the temperature increases when the temperature is between 400℃ to 800℃, the changes became more obvious as the temperature increase; The ringing count of the acoustic emission has a good corresponding relationship with a stress curve, which fully reflects the rupture evolution law of marble in different stages; Temperature has a significant effect on the destruction law of marble, as temperature rise, the failure of marble is from brittle failure to ductile failure .