Sound experimental design principles, rather than three-point curves, can be employed to determine high-strength concrete mixture proportions that maximize performance while minimizing cost. Importantissues on experimental design and empirical modeling are discussed.Graphical methods illustrate how high compressive strengths can be obtained for a wide range of costs--and how to get the most for yourmoney. An example is given using a classical experimental design. It greatly reduces the number of concrete mixes that otherwise would have been necessary to obtain information on five variables that change simultaneously. This experiment illuminates the effect of the silica fume addition percentage and the high-range water reducer dosage on 28-day compressive strength and raw material cost. Contour plots are provided to demonstrate the usefulness of a statistical approach. This paper appears in transportation research board record no. 1284, Cement, admixtures, and concrete 1990.
Samenvatting