Characteristics of concrete containing granulated blast furnace slag: a factorial design approach

The present study investigates strength and other properties of concrete by partially replacing natural river sand with granulated blast furnace slag (GBS). The general factorial design approach has been adopted for this investigation. Two factors i.e., water/cement (w/c) ratio and percentage of GBS (GBS(%)) have been selected. The (w/c) ratio level is taken as 0.45 and 0.5. The factor GBS(%) levels has been taken as 0, 20%, 40% and 60%. The strength properties of concrete, such as compressive strength (CS) after 3, 7, 28 and 90 days of curing period and modulus of elasticity (EM) and the other properties, such as density, water absorption (WA), and volume of voids (VV) after 28 days of curing, are taken as the responses in the analysis. The outcomes of the analysis are presented in the form of analysis of variance (ANOVA) table, main effect, individual, contour and interaction plots. It is observed that the selected factors significantly affect the selected responses. The strength and other properties are observed to be decreased with the increase in the w/c ratio from 0.45 to 0.5. However, these properties are enhanced by alteration of GBS(%) from 0 to 60%. Further, it is ascertained that the interaction of the factors has insignificant effect on the responses.