FIVE COMPONENT CONCRETE MIX OPTIMIZATION OF ALUMINUM WASTE USING SCHEFFE’S THEORY
The research investigated some mechanical properties of aluminum waste concrete to harness its structural properties in the construction industry. Aluminum waste which was obtained from Aluminum Extrusion Industry (ALEX) Inyishi in Ikeduru Local Government Area of Imo State was investigated. The mathematical models for the optimization of the compressive and flexural strengths of a five component concrete mix was obtained. A computer program for the optimization of the compressive and flexural strengths of aluminum waste concrete was developed. Scheffe’s experimental design technique was followed to produce concrete containing five components, which were used to cast cube and beam samples. The cubes and beams have dimensions of 150mm x 150mm x 150mm and 100mm x 100mm x 500mm respectively. The cube samples were tested for 7, 14 and 28 days strength. The result showed that the addition of 5% aluminum waste to a standard 1:2:4:0.55 mix caused compressive strength of the concrete to rise from 26.07N/mm2 to 28.47N/mm2. This result represents an increase of 9.21% in compressive strength. Aluminum waste produced no significant effect on the density, Poisson ratio, young’s modulus of the concrete. The computer program gave an optimum mix ratio of 1:1.1:1.75:1.15:0.7 (Cement, fine aggregate, coarse aggregate, aluminum waste, water), which generated a compressive strength of 29.81N/mm2, an increase of 14.35% in compressive strength over a standard mix. The result represented a saving of 16% by volume of concrete and a reduction of four thousand naira per cubic meter of concrete when compared with the standard mix. The computer program for the optimum mix ratio for flexural strength gave a value of 11.72N/mm2. There was an increase in flexural strength when compared to 9.46N/mm2 of the standard mix. The research concludes that aluminum waste concrete is economical and produces high compressive and flexural strength and can be used in structural members such as beams and columns where high compressive strength concrete is needed.