An Experiment to Determine the Prospect of using Cocoa Pod Husk Ash as Stabilizer for Weak Lateritic Soils

Abstract

A study was conducted to determine the extent to which the engineering and geotechnical properties of a lateritic soil for road construction works can be improved by using cocoa pod husk ash (CPHA) additive.Natural lateritic soil samples were collected from test pits near El wak Sports Stadium, Accra, Ghana and were subjected to Atterberg’s limit and particle size distribution tests as well as compaction and California Bearing Ratio (CBR) tests. The soil was then treated with 0.5%, 1.0%, 2.0%, 4.0%, 6.0%, 8.0%, and 10.0% of CPHA and then tested for variations in the engineering properties.From the various tests carried out on the natural soil sample, and when CPHA was added, it was observed that CPHA has a significant negative effect on the maximum dry density and a positive significant effect (p<0.05) on the liquid limit. The addition of CPHA to the soil however, did not significantly (p>0.05) affect the California Bearing Ratio, optimum moisture content, plastic limit and plasticity index, and therefore the CPHA is regarded as a poor soil stabilizer. Other findings show that CPHA has no pozzolanic properties.

Keywords: Cocoa pod husk ash, stabilizer, lateritic soil, pozzolanic properties