Effect of rice husk ash on soil stabilization at Dinajpur City

Abstract

Understanding local conditions is crucial for applying soil stabilization principles from other regions to a specific country for effective and sustainable stabilization methods. This investigative study delves into the suitability of locally available Rice Husk Ash (RHA) for incorporation into local building construction practices at Dinajpur, Bangladesh, aiming to minimize the volume of waste disposed of in the environment, thereby mitigating environmental pollution. Conventional soil stabilization techniques are becoming increasingly expensive due to the rising costs of stabilizing agents such as cement. Replacing a portion of the stabilizing agent with RHA could potentially reduce the cost of stabilization while also minimizing environmental harm. RHA comprises 85-90% silica, making it an excellent substitute for silica in soil stabilization. Silica is recognized as an effective binding agent alongside cement. The soil sample selected for this research is a highly plastic clay (CH), which necessitates significant strength enhancement. Three soil samples were stabilized with varying percentages of RHA and a minimal amount of cement. Observations were made to assess the changes in soil properties, including Maximum Dry Density (MDD), Optimum Moisture Content (OMC), and Unconfined Compressive Strength (UCS). The results obtained indicate that increasing RHA content leads to an increase in MDD but a decrease in OMC. Additionally, the UCS of the soil exhibits substantial improvement to up to 88% with increasing RHA content up to 10%. Based on the observed maximum strength enhancement, a 10% RHA content combined with 6% cement is recommended as the optimal combination for practical applications.