DEFORMATION AND FILTRATION IN CLAY MATERIALS CONSTITUTING TO THE SAFETY BARRIERS OF RADIATION HAZARDOUS FACILITIES

The paper focuses on the compression tests implemented to study one-dimensional deformation in dry and watersaturated state and pressure filtration in samples of dispersed materials developed as a construction material for waterproof barriers. These materials are made of kaolin, polymineral and bentonite clays and their mixtures. For the studied samples, the paper presents the plotted dependences between deformation, swelling pressure, capillary suction, permeability coefficients and the skeleton density (dry density). The study has confirmed that kaolinite containing materials tend to compaction and the montmorillonite – to swelling. The compression characteristics of a polymineral clay material and mixed materials do not always depend on the mineral composition alone. Swelling pressure manifests itself in case of bentonite and polymineral clay-based materials and is practically absent in materials made of kaolins and their mixtures with 30 wt. % bentonite. The permeability coefficients increase along with the growing ratio of kaolinite and montmorillonite contents, whereas it is the additivity that is characteristic for mixed materials.

 

Keywords: radioactive waste, waterproof barrier, kaolin, bentonite, effective pressure, skeleton density, odometer, deformation, swelling pressure, capillary suction, permeability coefficient.