Cement Stabilization for Improved Soil Performance: A Case Study of Ogume Clay Soil in the Niger-Delta Region, Nigeria

Abstract

This research investigates the use of stabilized sub-bases in coastal road construction. Three sample categories were examined: untreated soil, soil stabilized with 5% cement, and soil stabilized with 8% cement. The study focuses on cement stabilization due to its suitability and availability. CBR (California Bearing Ratio) tests were conducted on the natural sub-grade material, revealing low CBR values that indicated insufficient strength to withstand traffic loads without deformation. However, the addition of varying percentages of cement as a stabilizer resulted in a significant strength increase. CBR values improved from 15% for natural soil to 27%, 33%, 50%, and 86% for cement percentages of 5.0%, 5.5%, 6.0%, and 6.5% respectively. Sieve analysis showed reduced fines content in the stabilized materials compared to the non-stabilized ones. Compaction tests demonstrated increased Maximum Dry Density (MDD) and Optimum Moisture Content (OMC) for the stabilized materials. The liquid limit (LL) was zero, and the Plasticity Index (PI) indicated non-plastic behavior for all samples. The results highlight the positive impact of sand-cement stabilization on road construction materials in coastal areas, significantly improving their strength. The study emphasizes the importance of determining the appropriate stabilizer amount through laboratory testing and implementing robust construction techniques to ensure consistent strength in the road. CBR tests on the stabilized soil samples met the requirements for sub-base materials (CBR value of 30%) and base-course materials (CBR value of 80%) with higher cement percentages. The minimum cement percentages to meet these CBR requirements were found to be 5.36% and 6.48% respectively