Effects of stabilization on the behaviour of Finnish sensitive soils

The proposed note presents the results of an experimental activity aiming at studying the hydraulic and mechanical behaviour of a Finnish sensitive soil treated by fly ash and lime. A laboratory testing program was carried out both on treated and untreated soil; soil-binders samples were prepared by wet mixing of the components and by Standard Proctor compaction. Hydraulic conductivity tests were carried out in flexible wall permeameters; the compressibility was studied by incremental load oedometric tests. The results have shown a general increase of the hydraulic conductivity and a significant reduction in compressibility after binders addition; the extent of modification of soil properties was observed to depend upon the compaction water content of the soil. The soil treatment is generally economically convenient if compared to disposal in waste landfills, which would represent the only alternative for the soil type of concern. In addition, if a by-product such as fly-ash is able to act as effective binder in the mixture, this surely constitutes a promising perspective in terms of sustainability in the field of earthen structures.