Biotechnological Advances in Road Construction: The Impact of Biological Soil Amendments on Soil Remediation

Abstract

This study explores the application of biogenic soil amendments, specifically rice husk ash, in the remediation of soils used in road construction projects. Utilizing rice husk ash as a primary amendment material, combined with P.O 42.5 silicate cement and lime, we developed a novel curing agent aimed at enhancing soil properties for engineering applications. The efficacy of this biotechnological approach was evaluated through a series of laboratory tests, including unconfined compressive strength tests to assess the mechanical robustness and titration methods to analyze changes in specific surface area and swelling properties of silty clay soils. Our research focused on the engineering characteristics of the amended soils, particularly their resistance to sulfate erosion and the improvement in microstructural integrity under cyclic dry and wet conditions. The mercury intrusion porosimetry was employed to examine the pore size distribution and overall microstructure of the treated soil. Notably, increasing the rice husk ash content from 6.5% to 10.5% resulted in a significant reduction in the median pore size from 0.022 ?m, simultaneously decreasing the range of larger pores from 0.15 ?m to 1.1 ?m. This modification in pore structure substantially improved the density and stability of the soil, suggesting enhanced performance characteristics suitable for road construction applications. The results from this study demonstrate that biogenic amendments like rice husk ash offer a viable, sustainable solution for improving soil conditions in civil engineering projects. By increasing the content of small pores and enhancing the soil's mechanical properties, the biogenic amendment contributes to more durable and resilient infrastructure. This research underscores the potential of biotechnological innovations in addressing environmental and engineering challenges in road construction, providing a foundation for further exploration of sustainable material applications in the industry.