Comparative Evaluation of Concrete Properties with Varying Proportions of Periwinkle Shell and Bamboo Leaf Ashes Replacing Cement

Abstract

The paper examined the performance of ternary blended cement concrete incorporating periwinkle shell ash (PSA) and bamboo leaf ash (BLA) as cement supplements. PSA and BLA were obtained by burning periwinkle shell and bamboo leaves in a furnace at a temperature of 600oC for 20 minutes. The chemical analysis of the ashes revealed that they are amorphous in nature. A nominal mix of 1:2:4 with water-cement ratio of 0.65 was used as reference. The cement content of the reference was replaced with varying combined percentages (by weight) of PSA and BLA up to 40% given 10 mixes. A total of 360 cubes were cast, cured in water and tested at ages up to 56 days. The properties investigated were compressive and tensile strength, water absorption, porosity, and bulk density. The result revealed that at 28 and 56 days hydration, ternary blended cement concrete containing combined percentage of PSA and BLA of 20% cement replacement attained higher compressive and tensile strength and lower water absorption and porosity values than the reference. It is concluded that blended cement concrete of 20% cement replacement is the optimum proportion combination for ternary blended cement concrete.

Keywords: Bamboo leaf ash; cement replacement; Comparative evaluation; Concrete properties; Periwinkle shell ash; Varying proportions