Influence of cement-bentonite slurry mixing ratio on permeability of cutoff wall

As a kind of material for cutoff walls, cement-bentonite slurry was widely used in vertical anti-seepage system of landfills in the US and some European countries. The application and research of cement-bentonite slurry haven’t been well developed in China. Several different mixing ratios of slurry were prepared for study. The hydraulic conductivities of hardened slurry were tested using a permeameter. The influences of cement and betonite on the hydraulic conductivity of hardened slurry were explored. The results show that the influences of cement and bentonite on hydraulic conductivity of hardened slurry are interdependent. Only the participated amount of cement should reach a certain degree, the increase of bentonite used in the slurry can effectively decrease the permeability of hardened slurry. The hydraulic conductivities of hardened slurry also decrease evidently with curing time.