Effect of heat-treatment on the dynamic compressive strength of Longyou sandstone

Temperature plays an important role in many rock engineering practices. The increase or decrease of temperature induces the damage characterized by cracks/voids in the rock and thus reduces its strength. Therefore it is essential to quantify the damage induced by the heat-treatment and establish its correlation to the mechanical properties of rocks. In this study, X-ray Micro-computed tomography (CT), a non-destructive observation technique was utilized to quantify the damage induced by the heat-treatment. Using CT images, the damage variables were measured for Longyou sandstone (IS) at three heat-treatment temperatures, 250 degrees C, 450 degrees C, and 600 degrees C, and room temperature of 25 degrees C. The dynamic compressive strength of LS was then obtained by a modified split Hopkinson pressure bar system with the loading rate from 10(2) to 10(4) GPa/s. An empirical equation to quantify the correlation between the damage variable and the dynamic compressive strength was established from the experimental data. (C) 2015 Elsevier B.V. All rights reserved.