Impact of wetting—drying cycles on the mechanical properties of lime-stabilized soils

Abstract

This article addresses the results of an experimental study on the behavior of soil; this soil was exposed to long-term treatment with lime and numerous wetting-drying cycles. This research investigated the effect of a wide range of lime contents on the soil volume, soil water content evolution and durability (unconfined compressive strength (UCS), plasticity index (PI) and cation exchange capacity (CEC)) for stabilized soil in contact with water. This experimental study was performed on soil treated with lime (varying from no lime to 8%) corresponding to three levels of improvement: soil improvement only, stabilization and insensitivity to water, and long-term stabilization during wetting-drying cycles. The results indicated that the UCS increases, PI and CEC decreases with the lime level. For lime levels above 4%, the behavior of the treated soil under wetting-drying was satisfactory. Mineralogical analyses indicated that the formation of calcium silicate hydrate C-S-H, ettringite C-S-A-H is responsible for the increased or decreased strength of the treated soil. CaO, SiO2 and Al2O3 were three important minerals responsible for the increase or decrease in soil sample stabilization. Simple model executed in JMP statistical software was proposed and validated. We note that CaO and SiO2 have the most influential effects by very low values of probability for the responses studied, which confirms the hypothesis of that these models can be used to model UCS and PI in curing time and wetting-drying cycles.