Experimental Study of Swelling Characteristics of Backfill Mixture

Bentonite as deep geological disposal of high level radioactive waste in the buffer / backfill material,it is very necessary to study the physical and mechanical properties. In this paper,calcium bentonite and sand mixture were carried out to a series of swelling deformation studies using oedometer,to analyze the relationship between the deformation characteristics and initial dry density and water content. The test results show that swelling strain of bentonite and sand mixed depends on initial dry density and the bentonite content of mixture with increasing initial dry density increases,and the deformation decreasing with increasing the initial moisture content of the bentonite or mixture.