OPTIMISING TH E DESIGN OF CONCRETE MIXES USING DOE METHOD FOR UNCRUSHED AGGREGATES

Abstract

This paper discusses the numerical approach using linear programming technique for selecting proportions of various aggregates required to produce the desired concrete to meet a specification requirement. Firstly, the mix designs to produce normal grade concretcs was carried out and subsequently used to obtain the proportions of constituent materials of fine and coarse aggregates. Secondly, constraints of availability, cost and specification requirements were built into the minimization procedure and the results were compared with the mix design proportions produced. The outcome was found to be reliable. The specification requirements considered here are the strength and durability requirements. The minimization procedure, yields higher proportion coarse aggregate with 4.75 - 10mm grading for 20mm maximum aggregates. The application is facilitated by developing a computer solution procedure.