An experimental study to find the optimum dosage of admixtures in blended concrete

Abstract

Blended Concrete (BC) is environmental friendly concrete and could be considered as a construction material to promote the sustainable development. In this paper mineral admixture like Fly ash (FA), Ground Granulated Blast Furnace Slag (GGBS) and Alccofine (AL) were used with different combinations in different dosages as replacement for cement. Effects of varying dosages of mineral admixture, was studied for compressive strength of BC. Initially, the cement was replaced with FA and GGBS separately at 0%, 5%, 10%, 15%, 20%, 25%, 30%, 35% and 40%. The optimum percentage of FA and GGBS replacements were evaluated by the compressive strength. Keeping this optimum percentage of FA and GGBS as constant, further replacement of cement was done by AL at 6%, 8%, 10%, 12%, 14% and 16%. The study concludes that BC in the combination of FA and AL can be used for the general purpose of concrete as required compressive strength can be achieved. But the concrete with combination of GGBS and AL would not be useful in the formation of BC as the combination had failed to achieve the design strength and it had been clearly observed that as the AL percentage increases the compressive strength decreased.