Comparative experimental study on the physical and mechanical properties of quartz sandstone after water-cooling and natural-cooling under high temperature

Abstract

Experimental tests were conducted to study the influence of natural cooling and water cooling on the physical and mechanical properties of quartz sandstone. This study aims to understand the effect of different cooling methods on the physical and mechanical properties of quartz sandstone (such as mass, volume, density, P-wave velocity, elastic modulus (E), uniaxial compressive strength (UCS), etc.). The results show that the UCS and E of the specimens cooled by natural cooling and water cooling decrease with heating temperature. At 800°C, after natural cooling and water cooling, the average value of UCS decreased by 34.65 and 57.90%, and the average value of E decreased by 87.66 and 89.05%, respectively. Meanwhile, scanning electron microscope (SEM) images were used to capture the development of microcracks and pores within the specimens after natural cooling and water cooling. It was found that, at the same temperature, water-cooling treatment was more likely to cause microcracks and pores, which can cause more serious damage to the quartz sandstone. These results confirm that different cooling methods have different effects on the physical and mechanical properties of quartz sandstone, and provide a basis for the stability prediction of rock mass engineering in cases such as a tunnel suffering from exposure to fire.