Performance of soil stabilized with biopolymer materials – xanthan gum and guar gum

Biogeotechnology is a subfield of geotechnical engineering that utilizes microbial approaches to improve the engineering parameters of soil. The use of biological processes in the soil reclamation process shows great potential in terms of sustainability and environmental friendly compared to treatment using chemicals such as cement and lime. These additives are recognized to have less ideal environmental impacts due to, in particular, the high quantities of greenhouses that are typically created during production. In this case, one of the potential environmentally friendly and sustainable material options is to use biopolymers obtained from living organisms for soil stabilization, especially in tropical residual soils. However, the physical characteristics of biopolymers fluctuate significantly depending on their types and compositions. The primary purpose of this research is to examine the effects of small quantities of biopolymers on the physical parameters of residual soil (1%, 2%, 4%, and 5%), namely xanthan gum and guar gum. Atterberg limits, optimum water content, maximum dry density, pH, and specific gravity are among the parameters discussed in this research. The shear strengths of both treated and untreated soil at various curing times were experimentally investigated by performing an unconfined compressive strength test. A small amount of biopolymers increased the pH values, reduced the maximum dry density, improved the optimum moisture content, decreased the specific gravity, and also increased the plasticity index. Furthermore, the unconfined compressive strength results highlight that the strength of the soil tends to improve with the addition of biopolymers, highlighting its promising potential for sustainable engineering. •Assessing the usage of biopolymers, xanthan gum and guar gum in soil stabilization.•The biopolymer concentration is 1–5% by the dry weight of the soil.•Biopolymers enhance the strength of soil via hydrogen bonding.•Shrank brittle dry biopolymers generates strengthening effect variability in soil.•Bio-mediated soil reclamation is sustainable and environmentally friendly.