Experimental study of damage in granite Available to Purchase

The results presented here on damage of a granite from the centre of France are obtained using new experimental devices and a specific methodology in which the relation between strain and stress is obtained at different stages of damage using local strain measurements under high pressure. Mechanical tests have been undertaken under the load paths such as deviatoric compression and isotropic compression. Thus, at different stages of damage, the evolutions of elastic and plastic characteristics are obtained. Variations of Young's modulus, damage criterion and strength are presented as functions of irreversible volumetric strain considered as an internal damage variable. Induced anisotropy of mechanical properties clearly appears under isotropic compression loading. For example, the ratio of lateral strain over axial strain can reach 2·5 when the irreversible volumetric strain is equal to 1%.