Long-Term Stability Characteristics of a Lime-Treated Plastic Soil

There are several questions that are not well understood with respect to the long-term stability characteristics of lime-treated expansive soils in spite of being used as a conventional technique to improve the properties of expansive soils. This paper examines the long-term stability characteristics of FoCa bentonite soil (FoCa represents the first two letters of the two towns between which this type of soil is excavated: Fourgues and Cahaignes) using 4% lime treatment. The long-term stability characteristics referred to as durability in the paper were interpreted taking into account the influence of wetting–drying and freezing-thawing cycles on key engineering properties which include swelling and strength behavior of both untreated and lime-treated FoCa. In addition, leaching tests were carried out to study the Ca2+ions and pH concentration changes of the percolating water from both treated and untreated compacted expansive soil specimens analyze the permanence of the clay treatment. Finally, to highlight the changes induced in the texture of the material, pore size volume and distribution were investigated by mercury intrusion tests.