Preliminary study on sodium soda residue as impermeable barrier material in landfill liners

A serie of tests were firstly performed for soda residue and two practical impermeable clay specimens(weathered clay and locm)from two different MSW landfills of Qingdao to evaluate three soils several main indexes of three soils including compactibility,permeability,shear strength and shrinkage ratio.It was shown that soda residue has poorer compactibility,higher shear strength and lower shrinkage ratio than other two clay specimens,and moreover its permeability could be in the order of 10-7 cm/s when it was compaced under optimum or near to optimum water contents.Based on the above experiments,the soda residue was combinted with two clay specimens respectively,forming two types of mixture of soils(soda residue+weathered clay and soda residue+sloam)and two interbedded soils(soda residue/weathering clay and soda residue/subclay),and then their coefficients of permeability were tested.It could be concluded that for both interbedded soils and the mixture of soils with 30%～40% additive,the permeability was ranged in the order of 10-8 cm/s.