Enhancing the Properties of Expansive Soil Using Biopolymers—Xanthan Gum and Guar Gum

Abstract

Expansive soil poses problems to civil engineers in general and geotechnical engineers in particular. When geotechnical engineering structures such as foundations, retaining walls, pavements, side walls, canal beds and linings are proposed on expansive soil, they result in detrimental cracking due to alternate swelling and shrinkage. The methods of treating soil with chemical and cement grout are used widely in geotechnical projects. These conventional soil treatment methods have several shortcomings, especially from an environmental perspective. An attempt is made to use environmentally friendly materials, viz. biopolymers, to improve the soil properties. The present study illustrates the viability of two types of biopolymers, viz. xanthan gum and guar gum, as environmentally friendly additives for soil stabilization. Unconfined compression strength and one-dimensional consolidation tests are performed on both treated and untreated soil samples. It is observed that at 1% of xanthan gum there was an increase in strength of 630%, and at 1.5% of guar gum, it showed an increase in strength of 100% for 0 days. Use of xanthan gum and guar gum enhances the properties of expansive soil, resulting in an eco-friendly and sustainable substitute to traditional soil stabilization method.