Optimization of sustainable concrete mixes containing binary and ternary blends

Abstract

In this research 26 mixes in six different group were studied with three groups for each of the water cementitious material ratios (w/b) of 0.3 and 0.4 and a control mix. The first and fourth groups contained five percentages of silica fume (SF) as partial replacement of cement (5%, 7.5%, 10%, 12.5, 15%) for w/b ratios of 0.3 and 0.4, respectively. The second and fifth groups contained four percentages of Class F fly (FA) ash as partial replacement of cement (10%, 15%, 20% and 25%) for the w/b ratios of 0.3 and 0.4, respectively. The third and sixth groups contained three different percentages of both Class F fly ash and silica fume as partial replacement of cement with SF 5%+ FA 10%, SF 10%+ FA 15% and SF 15%+ FA 20% for w/b ratios of 0.3 and 0.4, respectively. For all of these mixes the compressive strength was first studied then the benefit greenhouse gases (GHG) ratio and Benefit cost ratio were found for all the studied mixes. Two optimization processes were performed during the course of this research, the first optimization process results can be used when the concrete durability is not a concern (concrete durability results are not accounted for). Whereas, the results of the second optimization process can be used when the concrete durability is a concern (concrete durability results are accounted for). The details of the results and the optimization processes are presented in this paper.

keywords Benefit Cost Ratio; Compressive Strength; Durability; Fly ash; Greenhouse gases; Optimization; Silica fume