Neogene clays from Poland as mineral sealing barriers for landfills: experimental study

Abstract Mineralogical and chemical compositions, as well as the physical properties of the Polish Neogene clays, justify the usage of this soil for mineral liners of waste disposal sites. However, low values of the strength parameters of these clays make them inapplicable as a raw material, but rather as a component of a mixture with another soil with higher values of mechanical parameters. Soil mixtures made of the clay from Budy Mszczonowskie and dune-sand in different weight proportions showed considerably better physical and mechanical properties as compared to raw clay. The values of isolation parameters were only slightly reduced. Mostly suitable soil mixtures containing 20% and 40% of sand have the following values of parameters: coefficient of permeability k f =1.83×10 −10 and 3.80×10 −10 m/s; cation exchange capacity CEC=270 and 229 mval/kg; angle of internal friction ρ =6.7° and 17.5°; void ratio e =0.37 and 0.35; and plasticity index of 16% and 12%, respectively. This set of parameters sufficiently characterizes the suitability of a given soil for use as a mineral base liner and may be used for the valorization of soils. The Neogene clays are widespread and readily available over a considerable part of Poland. They are prospective sealing materials applicable to the construction of landfills.