Evaluation of the Strength Characteristic of Soft Clay Soil Stabilized with Rice Husk Ash and Fly Ash Blend

Abstract

This study presents evaluation of strength characteristic of soft clay soil stabilized with rice husk ash and fly ash blend. The index properties, compaction characteristics, unconfined compressive strength (UCS) and CBR of the soft clay soil stabilized with 2:4, 4:6, 6:8, 8:10 and 10:12% rice husk ash and fly ash blend were explored. British Standard light, British Standard Heavy and West Africa Standard compactive efforts were used. From the results, the clay sample is classified as A-7-5 or SC soil type. The results showed a decrease in Liquid and Plastic limits with increase rice husk ash and fly ash. It further shows 62-76% increment in Maximum Dry Density (MDD) of the stabilized soil with progressive increment in compactive effort. The CBR and UCS of the clay were improved by 356% and 106% respectively with the optimal values obtained at 2:4% Rice husk ash and Fly ash addition. The study has established the potential of using rice husk ash and fly ash to stabilize a class of soft clay soil for construction purposes.