Improving the Strength Properties of Afari and Mfensi Clays by Chemical Stabilization

Abstract

Physical and chemical studies were conducted on Afari and Mfensi clays in Atwima Nwabiagya District in Ashanti Region of Ghana, with the view of improving their strength properties by chemical stabilization with cocoa pod ash (CPA) and lime as chemical stabilizers. The idea was to produce stabilized clay brick without firing as an improved building material for the rural housing in areas where the materials exist and beyond. The results revealed an improvement in both dry and wet compressive strengths with the additions of 10% to 15% lime and CPA. The maximum dry compressive strength of 2.07N/mm2 and 5.85N/mm2 and wet compressive strength of 0.91N/mm2 and 2.67N/mm2 respectively were recorded for Afari and Mfensi clays. The water absorption also reduced from 100% to 27.59% and 17.78% respectively for Afari and Mfensi clays. Although there were decreases in wet compressive strength on soaking the specimens in water, the stabilized bricks did not disintegrate after 28 days of soaking. Moreover, the stabilized clay bricks showed good durability behaviour and did not disintegrate when exposed in the open air for two years.