Effect of Bio-Cementation with Rice Husk Ash on Permeability of Silty Sand

Abstract

The scarcity of competent soils in the desired locations has forced geotechnical engineers to look for soil stabilization that is sustainable and environment-friendly. In this regard, bio-cementation technology has received a lot of interest in this area because of its benefits over traditional soil stabilization techniques. The present study aims to examine the influence of the bio-cementation technique with and without Rice Husk Ash (RHA) on the permeability property of silty sand. Biocemented soil samples were prepared with various combinations of the bacterial solution (0.5, 1.0, and 1.5 optical density (OD)) and cementation solution (0.5, 1.0, and 1.5 molarity) at 0, 3, 7, 14, and 28 curing days. The RHA, an agricultural waste with good pozzolanic qualities, was added to the control soil and the biocemented soil samples at 5, 10, and 15% by weight. A falling head permeability test was employed in this study. The test results showed that the permeability of the soil decreased when the bio-cementation technique, with or without RHA, was applied. The permeability of the soil decreased with increasing BS and CS concentrations in all curing days. A greater decrease in the permeability value was seen when the RHA additive was added to the bio-cemented soil. The results of the micro-analysis tests were also in support of this reduction. Overall, the addition of RHA up to 10% with 1.0 OD BS and 1.0M CS at a 14-day curing period was noted to optimally reduce the permeability property of the soil.