Studies on resaturation processes and structural characteristics of the Callovo-Oxfordian claystone using X-ray microtomography and digital volume correlation

Abstract

Claystone formations in their natural state are favorable for geological disposal of radioactive waste. Nevertheless, disturbances and water loss generated around the excavated areas might change the favorable properties of formations. Similarly, water loss and resaturation during sample preparation can also cause variations in the mechanical properties. To investigate the influences induced by these actions, resaturation processes in a claystone were studied using X-ray microtomography and Digital Volume Correlation (DVC). Structural characteristics of Callovo-Oxfordian (COx) claystone inside the sample during resaturation processes are visualized in the form of images. Strain fields demonstrate the non-uniform deformation behavior of the sample during the resaturation processes, as well as details of local deformations. The results indicate that the effects of resaturation processes on the claystone cannot be ignored for the laboratory testing at the sample scale.