Abstract: The rising cost of construction materials in developing countries has necessitated research into the use of alternative materials in civil engineering construction. Concrete mix design is a process of proportioning the ingredients in right proportions. Though it is based on sound technical principles and heuristics, the entire process is not in the realm of science and precise mathematical calculations. This is because of impreciseness, vagueness, approximations and tolerances involved. In this study concrete mix of M35 was used as control, while fly ash was used to replace high alumina cement by volume. Eighty cubes ere produced and the weight and compressive strengths were evaluated at 1st day, 3rd days, 7th days, 14th days and 28th days. This paper also presents the development of a novel technique for approximate proportioning of standard concrete mixes as suggested in IS: 10262-2003 and IS456-2000. The results in terms of quantities of cement, fine aggregate, course aggregate, water and fly ash obtained through the present method for various grades of standard concrete mixes are in good agreement with those obtained by the prevalent conventional method. Details of the system model are described and comparative graphs are presented.

Keywords: Concrete Mix Design, Compressive strength, Fly ash (FA), High alumina cement (HAC).