Effect of Coconut Shell Husk Ash and Palm Kernel Shell Husk Ash on the Grading and Consistency Behaviour of Pozzolan Stabilized Oboro Lateritic Soil

Abstract

The effect of Coconut shell husk ash and palm kernel shell husk ash on the grading and consistency of oboro lateritic soil stabilized with pozzolan has been studied in this research. Results of the grading analysis have shown that the natural soil was classified as A-7-6 soil according to the AASHTO classification system and CH- inorganic sandy fat clay according to USCS. The consistency result of the natural soil showed that the soil is highly plastic with a plasticity index of 54.4% ˃ 17. The admixtures were used in the proportions of 2%, 4%, 6%, 8% and 10% and their proportional effect on the grading behaviour of the pozzolan stabilized soil showed that the uniformity and curvature of the soil improved with increased admixtures. CSHA recorded a better improvement with the uniformity of the soil while PKSHA recorded better improvement with the curvature of the soil. The consistency limits results showed that the plasticity of the stabilized soil decreased with increase in percentage of admixtures making the mixture less plastic. Finally it has been established that CSHA and PKSHA are good admixtures in the stabilization of weak and highly plastic engineering soil and are recommended for use.

Keywords: Coconut shell husk ash, palm kernel shell husk ash, grading and consistency behaviour, oboro lateritic soil, stabilized.