Gas transport in a binary bentonite mixture used in sealing systems

Binary mixtures composed of 80% high-density pellets and 20% granular bentonite at hygroscopic water content are currently considered for use in vertical sealing systems the deep longterm disposal radioactive wastes. By pouring dry components without compaction, mixturedisplays a density around 1.49 Mg/m3. However, these subjected to long-term hydrations from surrounding formations with possibility having zones entrapped generated gas that makes it challenging display homogeneous saturation seal. Therefore, transport through bentonite-based materials different degrees is crucial issue. Hence, several oedometer tests have been conducted evaluate impact injection on this mixture constant density. These injection/dissipation were performed stress or volume conditions. The results provided variation effective permeability breakthrough pressure aftersaturation. Furthermore, interpreted microstructural study focusing volumetric filling inter-pellet porosity.