Volume 5, Issue 3 (March 2008)
Temperature Effects on Physical Properties and Mechanical Behavior of Granite: Experimental Investigation of Material Damage
In this paper, the effect of thermal treatment on physical and mechanical properties of a granitic rock is experimentally investigated. The open porosity, gas permeability, P-wave velocity (and their attenuation), ultimate strength, and Young’s modulus are measured on samples heated at temperatures ranging from 105°C to 600°C. First, results show good correlations between the evolution of physical properties and the amount of the damage induced by the thermal treatment. Second, the mechanical parameters are shown to be dependent on the microcracks’ density in the samples. The effect of temperature on the failure process in granite is also investigated using strain gauge measurements and permeability evolution in a uniaxial compressive test. The results show that the extent of the crack closure stage depends on the initial crack density and that the crack thresholds, which characterize the failure process of the rock under compressive loading, decrease with the thermal treatment.