ABSTRACT
Beside mineral liner materials, bentonite and bentonite-soil mixtures play an important role as a lining material for landfills. The reduction in hydraulic conductivity of a sand-bentonite mixture depends on the bentonite type used, as well as on the percentage of bentonite introduced in the mixture. It is clear that in a sand-bentonite mixture the sealing properties are a function of the bentonite content: the higher this content, the more severe the increase in the hydraulic conductivity of the mixture may be, due to the partial loss of bentonite unique properties. The scope of the experimental programme in the laboratory was to study the effects that leachates and chemical fluids that may be present in a sanitary landfill have on the hydraulic conductivity of a sand-bentonite mixture. Laboratory tests were performed to find out the effects of the permeation of the fluids on bentonite and sand-bentonite mixtures and on the fluids themselves.
