Geotechnical Properties of a Low-Plasticity Clay with Biopolymer

Abstract

This study presents geotechnical characteristics of a low-plasticity clay improved by xanthan gum biopolymer, which is an innocuous microbially induced polymer with high tensile strength. The samples were prepared by mixing clay at various proportions by weight of xanthan gum biopolymer (, .5, 1., 1.5, 2., and 3.%), and then tested at the end of different curing times (, 7, 28, and 56 days). To demonstrate the influence of xanthan gum biopolymer on the clay, an intensive series of unconfined compressive strength, laboratory vane shear, fall cone, oedometer, permeability, swelling, and shrinkage tests were carried out on the samples. According to the testing results, strength of the clay samples increased with both the content of biopolymer and the curing time. The test results also indicated that permeability of the samples with xanthan gum biopolymer is lower, while the compression index and swelling percentage values are higher than the samples without treatment. Evidently, xanthan gum biopolymer application was identified as an environmentally friendly and sustainable alternative material for improving a clay.