Stabilization Mechanism of Calcium Lignosulphonate Used in Expansion Sensitive Soil.

A series of tests were performed to investigate the macroscopic properties and the stabilization mechanism of calcium lignosulphonate modified expansive soil. Compared with natural soil, soil modified by 4% calcium lignosulphonate showed 56.5% increased 28 days unconfined compressive strength and 23.8% decreased free expansion rate. The X-ray diffraction analysis results indicate the existence of cation exchange and the reduction of montmorillonite interplanar spacing. The X-computed tomography results demonstrate that calcium lignosulphonate decreased the porosity and optimized the pore distribution. The calcium lignosulphonate also increased the stability of the suspension system according to the Zeta potential results. Moreover, the results of rheological tests show that the moderate amount of calcium lignosulphonate enhanced the yield stress and the plastic viscosity, proving the formation of a strong connection between soil particles. [ABSTRACT FROM AUTHOR]