Potential of snail shell and palm kernel shell powders in improving engineering properties of clay

Abstract

This research is aimed at using Snail Shell Powder (SSP) and Palm Kernel Shell Powder (PKSP) in stabilizing clay. Elemental and oxide compositions of the powders were determined and they revealed SSP is richer in CaO than PKSP. Sieve Analysis, Compaction, California Bearing Ratio (CBR) and Atterberg Limit were conducted on natural and stabilized soil mixture. The natural soil (A-7-6) was blended with SSP and PKSP at varying proportion of 2%, 4%, 6%, 8%, and 10% by dry weight of soil respectively and also combined at ratios not more than 10% total . Inclusion of additives increase the Maximum Dry Density (MDD) while it predominantly  the Optimum Moisture Content (OMC) values of the stabilized soil mixture. Plasticity Index (PI) decrease with the addition of the powders with the best performance observed mostly with SSP blended soil. It was also found that the CBR values of soil increase with corresponding increase in dosage of the powders. Soil blended with 8% SSP offered the best result with increase in MDD from 1198 to 1300kg/m³ while the combined additives gave the best result at 2%SSP+8%PKSP addition with MDD increasing to 1266 kg/m³ and further reduction of OMC to 21%. The best results in PI were from Soil blended with 2% SSP and also 2%SSP+8PKSP with 6.25% and 9.2% respectively. For CBR, soil blended with 8% SSP and 2%SSP+8PKSP of combined ratio gave peak performances. The potential of these additives in improving soil properties and reducing construction cost of road are presented.

Keywords: Palm kernel shell Powder, Snail shell powder, Clay stabilization, Geotechnical properties