Soil improvement and stabilization are important geotechnical issues when using soil as an engineering material. The most widely used material for soil treatment is cement, a trend that runs counter to environmentally friendly practice. In food and medical science, various biopolymers are commonly used as thickeners, stabilizers, binders, and so on. This study explores the feasibility of using environmentally friendly biopolymers for soil improvement. A commercial β-1,3/1,6-glucan polymer product was used to improve the strength of the Korean residual soil, hwangtoh. Liquid type β-1,3/1,6-glucan polymer solutions with different concentrations were mixed with hwangtoh and cured under different temperatures. The time-dependent compressive strength was measured in order to observe the strengthening mechanism of the β-1,3/1,6-glucan polymer-treated hwangtoh. The particle surface adsorption and tensile strength of the β-1,3/1,6-glucan polymers significantly increased the compressive strength of the hwangtoh. The strength improvement was maximized under a curing temperature of 60 °C. Furthermore, a simple economic/environmental analysis revealed that the β-1,3/1,6-glucan polymer treatment had advantages not only in strengthening the hwangtoh but also in lowering its environmental impact while offering financial competitiveness over ordinary cement treatments.
