Journal of Emerging Trends in Engineering and Applied Sciences: Research Areas

Article Title: Optimum Mix Design for Minimum Concrete Strength Requirement Using Akure Pit-sand as Fine Aggregate
by S.A. Alabi, L.M. Olanitori, and J.O. Afolayan

Abstract:
This paper highlights the properties of pit-sand commonly used as fine aggregate and the resulting concrete produced in Akure, South-west of Nigeria. The research into the characteristics and behaviour of locally available aggregates is expected to improve the knowledge of the structural engineers as well as all the civil engineers that make use of concrete. The main aim of this research is to develop optimum proportioning of local aggregate suitable for the customization of BS8110 (1997) in Nigeria. Linear programming technique has been applied to a concrete mix design having least cost while satisfying given water-cement ratio; the specified limits for the range of acceptable workability, expressed in terms of the compacting factor; absolute volume constraint and the specified compressive strength. The objective function, for which a minimum is sought, is the cost of concrete per cubic meter, expressed as the sum of the unit costs of the individual ingredients. The characteristic strength of the concrete at 28 days was found to be 10.44 N/mm2 at an optimal mix ratio of 1:2:5 and water-cement ratio of 0.77.

Keywords: pit-sand, concrete, compressive strength, optimization.

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