Influence of mineralogy and moisture content on plasticity and induced anisotropic damage of a claystone: application to nuclear waste disposals

The influence of mineralogy and moisture content on mechanical behaviour of a claystone rock is studied by the way of uniaxial and triaxial compressio n tests and microscopic observations. Some parameters characteristic of phe nomena like plasticity and induced anisotropic damage are discussed as a fu nction of these two factors. Rock behaviour becomes more brittle when calci te content grows or when clay or moisture content decreases. At the microle vel, plasticity is induced by slip of clay sheets and induced anisotropic d amage appears by growth of oriented microcracks at the interface between gr ains and matrix.