Stabilization of Soil Using Grinded Rice Husk Powder for Pavement Application

This study examined the effectiveness of ground rice husk powder (GRHP) as a sustainable stabilizing material for improving the engineering properties of lateritic soil intended for pavement subgrade applications. Laboratory investigations were conducted on natural soil and soil samples stabilized with varying GRHP contents of 0%, 2%, 4%, 6%, 8%, and 10%. The experimental programme included Atterberg limits, Standard Proctor compaction, soaked California Bearing Ratio (CBR), and Unconfined Compressive Strength (UCS) tests. The results revealed a continuous reduction in liquid limit and plasticity index with increasing GRHP content, indicating reduced soil plasticity and improved stability. Compaction results showed a decrease in optimum moisture content and an increase in maximum dry density, with optimum performance achieved at 8% GRHP. Similarly, CBR and UCS values increased significantly with the addition of GRHP, attaining peak values of 19.6% and 166.7 kN/m², respectively, at 8% GRHP, before showing a slight decline at higher contents. These findings demonstrate that GRHP enhances the strength and load-bearing capacity of lateritic soil. The study concludes that ground rice husk powder is an effective, economical, and environmentally friendly soil stabilizer, with an optimum content of 8%, suitable for pavement subgrade improvement.