SEM-EDX study of bentonite alteration under the influence of cement alkaline solutions

Bentonite is a key barrier for the isolation of high-level radioactive waste within Deep Geological Repository. However, bentonite may be altered by contact with cementitious materials and their alkaline pore fluids. This study offers an extensive morphological semi-quantitative characterization surface exposed to three types fluids released different cement-based materials. The surfaces were studied using thorough scanning electron microscopy exploration analysed energy-dispersive X-ray detector (SEM-EDX). In addition, statistical, element mappings, diffraction infrared spectroscopy analyses performed. aim was have picture chemical alterations at very early stages in accordance integrated approach necessary address stability long-term. As consequence reactivity, two morphologies stood out matrix bentonite: platelets coatings-like crusts characterized high Mg Ca content. These presented scope depending on type solution involved suggested precipitation authigenic magnesium silicate hydrates (M-S-H) and/or trioctahedral clay minerals Ca?carbonates. knowledge performance subjected these solutions can help evaluation most suitable used next bentonite.