Optimization of Calcined Beans Pod Ash – Cement Blended Concrete Mix Using Taguchi Method

Abstract

This study investigated the optimization of calcined beans pod ash (BPA) - cement concrete mix using the Taguchi method. Concrete is a widely used building material with various performance requirements. These requirements are mostly influenced by concrete constituent materials and mixtures proportion obtained from concrete mix design. But improper mix design can result in inherent defects or local imperfections, which can significantly deteriorate the performance properties of concrete and jeopardize the structural integrity and durability of concrete structure. Taguchi method of optimization was employed to address these challenges. It involves identifying key factors (water – cement ratio, percentage of BPA – cement replacement, fine to total aggregate ratio and super-plasticizer dosage), selecting suitable levels for these factors, and conducting experiments to determine the optimum combination of factors. The effects of these variables on concrete slump flow (SF), compressive strength (Fcu), and split tensile strength (Fy) were evaluated. The results of SF, Fcu and Fy of BPA – cement concrete show significant improvement of 23.74%, 21.72% and 21.43% respectively, when cement was partially replaced with BPA from 5% to 20%. Likewise, an improvement of 5.97%, 5.69% and 5.37% for SF, Fcu and Fy of BPA – cement concrete, when the dosage of super-plasticizer in concrete mix was varied from 6% to 12%. A respective optimal parameter combination for BPA – cement concrete slump and strengths were obtained at 0.40, 5%, 0.4, 6 ml/kg of cement and 0.35, 5%, 0.4, 6 ml/kg of cement for W-C, BPA, F-T Agg, SP respectively.