Experimental Study on the Evolution of Granite Permeability Under Thermal Shock

Abstract

In order to reveal the change law of permeability of high-temperature granite under thermal shock, the permeability of granite specimens at different temperatures was investigated under four cooling conditions: natural cooling in air and thermal shock cooling in water (20 ℃, 60 ℃, 100 ℃). The change rule was analyzed, and the thermal shock damage at different cooling temperatures was quantitatively characterized with the help of the 'thermal shock factor'. The research results show that the increase in the permeability of specimen under thermal shock is exponentially related to the increase in rock temperature; cooling medium and the temperature difference between high-temperature rocks and the convective heat transfer coefficient together affect the rate of heat exchange during thermal shock process and then affect the result of thermal shock damage; the thermal shock factor can be used as a physical quantity to measure thermal shock damage ability; and the penetration of granite after thermal shock damage increases monotonously with the thermal shock factor to a threshold, after which the permeability of specimen increases greatly with the increase of the thermal shock factor.

Keywords

• high temperature granite
• rock thermal shock
• permeability
• cooling medium temperature