Effects of Cement–Sodium Silicate System Grout on Tropical Organic Soils

Abstract

Tropical organic soils, generally formed in a natural environment and accumulates wherever the conditions are suitable, that is, the area with excess rainfall and the ground is poorly drained, irrespective of latitude or altitude. These soils commonly occur as extremely soft, unconsolidated superficial deposits with very low shear strength. Cement, sometimes with other industrial binders, is widely used for the stabilization of these soils by deep mixing method. However, these soils lack a favorable structure for the chemical reactions, coupled with a high moisture content which is acidic in nature, the efficiency of the binders is low or making it an expensive option. This paper investigates the effect of different components of cement–sodium silicate grout system on the strength and moisture content of organic soils by carrying out vane shear test and scanning electron microscopy test on samples treated and cured for up to 90 days. The study showed that cement and sodium silicate (in specific ratios) were highly effective in improvement of the shear strength along with a reduction in the moisture content of the treated soil. Further, with an increase in calcium chloride concentration in the confection, the shear strength and moisture content were observed to vacillate. The organic content present in these soils was found to have an adverse effect on the stabilization process.