Behaviour of saline soils (sebkha soils) treated with a hydraulic binder

Abstract

Chemical stabilization through cement and lime treatment is a common technique for improving weak soils. Among these, Sebkha soil, usually found in arid and semi-arid regions, presents significant engineering due to its low bearing capacity and high compressibility. This soil consists mainly of fine particles, including quartz sand and silt, with minor clay content, naturally cemented by salt minerals such as halite, gypsum, and calcite. In nature, water infiltration and flooding cause the dissolution and migration of salt minerals in Sebkha soil, reducing its salinity and weakening the cementing bonds between particles. This deteriorates the soil's physical and mechanical properties. Therefore, quantifying the salinity effect on the geotechnical properties of untreated and treated Sebkha soil is of interest. In this study, Ain M'lila Sebkha soil, characterized by high salinity of =23.2 dS/m and classified as chloride-sulfate soil, was investigated. The first part of this study was devoted to the quick lime treatment effect of the physicochemical and mechanical properties of Sebkha with different salinity levels of ECe3= 23.2 dS/m, ECe2=8.3 dS/m, and ECe1= 2.32 dS/m. The second part was devoted to studying the potential stabilization of Sebkha at high salinity with sulfate-resistance cement (SRC). UCS, carbonation, and granulometry tests were carried out to assess the soil's physico-chemical and mechanical properties. Subsequently, XRD, FTIR, TGA, pH, and EC measurement tests were performed to understand better chemical reaction development and their potential interactions with water-soluble salt minerals.