Development of self-compacting concrete using contrast constant factorial design

Abstract

The objective of this study is to determine if adjustment of the four factors viz. cement content (C), water to powder (w/p) ratio, fly ash (FA) content, and superplasticizer (SP) will increase the compressive strength of self-compacting concrete (SCC) by using contrast constant factorial design and response surface methodology. The method of the analyzing 2k factorial design that is a design with k factors each at two levels was used with 16 factorial points. It is concluded that the interactions of the parameters of a couple effect of C with SP, w/p with SP, FA with SP, and C with FA and SP in a full quadratic model are the only significant effects and the underlying assumptions of the analysis are satisfied. In maximizing compressive strength, variables such as cement content A or x1, water to powder ratio B or x2, fly ash content C or x3, and super plasticizer dosage D or x4 should be at a high level of significance and the process is relatively robust (exhibiting strength) to superplasticizer D.