An insight into grain interaction in bentonite/claystone mixtures

This paper investigates the swelling mechanism of Callovo-Oxfordian (COx) claystone grain in its mixtures with bentonite which are potential candidate for engineered barriers French high-level radioactive waste disposal. The pressures MX80 bentonite/COx various fractions and dry densities were first experimentally determined by carrying out infiltration tests under constant-volume conditions. According to experimental results, void ratio after hydration was estimated taking into account bentonite/claystone interaction. Then, volume change different applied swollen determined. volumetric strain found decrease linearly increase pressure. allowed indirect determination pressure grain. value be comparable that from relationship between direction perpendicular stratification intact COx claystone, confirming identified mixtures.