OPTIMIZATION OF COMPRESSIVE STRENGTH FOR MAXIMUM STRENGTH AND DURABILITY OF OKHUARE SANDCRETE BLOCK USING RESPONSE SURFACE METHODOLOGY

Abstract

This study investigates the compressive strength of sandcrete blocks in Benin. Samples of sand, cement, water and commercial sandcrete blocks were produced. These samples were transported to the laboratory for testing, various test was conducted on the sand, cement and water samples, including failure load, water absorption, mass, density and compressive strength. The blocks were produced using an egg laying machine. Mixing of the constituent was done manually. The mixture was then loaded into the moulds of the machine were they were vibrated, compacted and demoulded immediately. All the blocks were cured, under shade for twenty-eight days. The laboratory investigation was carry out to determine the density, mass, water absorption, failure load and compressive strength of the blocks. To improve the quality of sandcrete blocks produced, Optimization was carry out using response surface methodology with central composite design which generated 20 experimental runs. The mass of block and water absorption were minimized, density, failure load and compressive strength were maximized. Mass is 27.3287kg, density is 2149.19kg/m³, failure load is 234.861kN, water absorption is 6.60831 and compressive strength is 4.08817N/mm² were obtained. The optimum value of process parameters was determined. Water is 0.56, Cement is 0.42, and Sand is 10.00. A mathematical model that can adequately explain the effects of the process parameters on the strength and durability of the sandcrete block was developed and the most significant factor influencing the strength of the block was identified and statistically justified.

Keywords: Sandcrete Block, Compressive Strength, Durability, Water, Cement, Concrete, Optimization, RSM

DOI: 10.7176/IEL/14-1-06

Publication date: July 31^st 2024