Experimental investigation on rock mechanical properties and infrared radiation characteristics with freeze-thaw cycle treatment

Abstract

The effect of freeze-thaw weathering cycles caused by diurnal and seasonal temperature changes is a significant disadvantage in the stability of rock engineering in cold regions. To investigate the evolution rule of rock strength and infrared radiation characteristics of igneous, metamorphic, and sedimentary rock subjected to freeze-thaw weathering cycles, freeze-thaw weathering cycle treatment was conducted on coarse-grained granite, fine-grained marble and soft red sandstone from cold regions in Western China. The nondestructive detection technique of nuclear magnetic resonance (NMR) was used for rock damage detection. Infrared thermography was used to monitor the rock debris movement, crack propagation and average infrared radiation temperature (AIRT) during unconfined compressive strength (UCS) testing. The mechanisms of rock damage and change in AIRT induced by freeze-thaw weathering cycles were carefully analyzed. According to the UCS evolution rule, the ranking order (from high to low) of the results of rock resistance to freeze-thaw weathering processes is as follows: marble, granite and sandstone. An indicator called the infrared radiation rate was proposed to measure the rate of increase in infrared radiation temperature with increasing stress during the UCS tests. The rank order (from high to low) of the infrared radiation rate results is as follows: sandstone, marble and granite. Based on the infrared images and photographs of the failed rock specimens, the failure patterns and processes of the different rock types are investigated.