Studies on lithomargic clay stabilized using granulated blast furnace slag and cement

Abstract

Southwestern coast of India has vast deposits of problematic silty soil (locally called shedi soil) normally referred as lithomargic clay in the literature. This problematic silty soil is characterized by its high sensitivity to moisture content with high erosion potential and low shear strength, especially in wet conditions or when it absorbs sufficient moisture. In order to overcome these problems, an industrial by-product obtained from the iron industry i.e. granulated blast furnace slag (GBFS) has been used to improve the strength properties of the lithomargic clay. To achieve the study objectives, lithomargic clay was replaced with the GBFS in different proportions. From the experimental results, it was observed that lithomargic clay when replaced with 25% GBFS produced good improvement in UCC strength and shear strength. The study includes an investigation on a combination of lithomargic clay replaced by optimum percentage of GBFS with addition of varying percentage of cement on their shear strength parameters. The improvement in strength was justified by conducting microstructural analysis using SEM and XRD. The experimental results are used in numerical analysis i.e., in PLAXIS 2D for load-settlement analysis of a strip footing and for a typical embankment slope stability problem. In addition, studies were carried out to check the effectiveness of GBFS and cement in the production of compressed stabilized earth blocks (CSEB). From the current study, it is concluded that lithomargic clay stabilized with GBFS and cement can be effectively used in geotechnical applications, thereby increasing the rate of effective disposal of GBFS.