Compaction and sealing properties of bentonite/claystone mixture: Impacts of bentonite fraction, water content and dry density

Compacted block composed of 70% crushed Callovo-Oxfordian claystone and 30% MX80 bentonite has been proposed as a possible material for sealing potential repository radioactive waste. In this study, the compaction property bentonite/claystone mixtures with various fractions water contents were first investigated to define an appropriate protocol fabrication blocks. Results show that increase fraction decreased overall compressibility achievable dry density at given stress. As content increased, relatively low vertical stress increased due increasing deformability aggregates decreasing inter-aggregate friction; contrarily, high stress, lower was observed samples higher because larger required squeeze within aggregates. During demoulding, demoulding pressure content. Then, assess suitability material, swelling pressures hydraulic conductivities compacted blocks determined. It found conductivity increases density. By contrast, more intercalated in interlayer spaces pore volume decreased, resulting reductions conductivity.