Biopolymer as Environmentally Friendly Reinforcement to Overcome Cracked Soil Problems on Expansive Soil:

Abstract

The distribution of soft and expansive soil that is often found in Indonesia often causes problems in the structure above it. To build the infrastructure on expansive soil, it is necessary to improve the subgrade. One method to improve soil is to stabilize it by using biopolymers. Biopolymer was chosen because it is more environmentally friendly than the use of cement as soil stabilization. In this study, Xanthan Gum (XG) biopolymer was used, with concentrations of 1%, 2%, and 4%. Testing was carried out experimentally in the form of testing physical and mechanical properties as well as cyclic drying testing. From the results of the analysis, the XG biopolymer can reduce the number and width of cracks after experiencing a drastic reduction in water content. A positive impact was also obtained on the mechanical analysis with the addition of biopolymers that could increase the compressive strength of the soil up to 432% and the shear strength of the soil up to 482%.