Characterization and preparation of eco-friendly foamed concrete using a foaming agent: Optimizing the design by Taguchi analysis

Abstract

Solid waste management has emerged as the primary global environmental challenge due to the constant production of increasing waste by-products and materials. Using waste materials makes concrete production economical and helps resolve disposal problems. The effects of lightweight foam concrete reinforced with corncob ash (CA) and basalt fibre (BF) on durability, thermal conductivity, and mechanical properties are investigated elaborately in this study. The foam concrete mix is prepared in three series with a foam (F) content of 25, 50, and 75 kg/m3 with and without the CA and BF reference mixes. The mix of corncob ash is chosen as a cement replacement in six different concentrations: 0%, 20%, 30%, 40%, 50%, and 60%. In addition, compositions of 0.5%, 1.5%, and 3% basalt fibre length variation were incorporated into the weight of the cement. Split tensile, compressive, and flexural strengths are determined at 7, 14, and 28 days. The workability, porosity, durability, and thermal characteristics are also examined. This study analyses the confirmation experiment to verify the optimum mix proportions of lightweight foam concrete by applying Taguchi’s experimental design for concrete mixes incorporating by-products as a partial cement replacement. Adding BF improved the mechanical properties of compressive, tensile, and flexural strength, whereas adding CA decreased porosity and thermal conductivity. The 50% CA with 1.5% BF blended concrete with 50 kg/m3 F exhibits high strength compared to 25 and 75 kg/m3 at all ages. The split tensile strength of the F50CA50BF1.5 mix varies from 2.19 MPa to 2.73 MPa, and the compressive strength of 29.13 MPa is higher than that of 14.36 MPa, 18.63 MPa, and 0.88 MPa for the R 25, R 50, and R 75 kg/m3 mixes. The highest mechanical strength and improved durable properties are achieved by replacing 50% of CA and 1.5% of BF with F 50 by-products at all curing periods.