Experimental Study on Partial Replacement of Cement by Flyash and GGBS

This paper presents a laboratory investigation on optimum level of Fly ash and Ground Granulated Blast Furnace Slag (GGBS) as a partial replacement of cement to study the strength characteristics of concrete. Portland cement was partially replaced by 5%, 6%, 7%, 8%, 9%, 10% of GGBS and Fly ash by 20%, 40%, 60% respectively. The water to cementations materials ratio was maintained at 0.45 for all mixes. The strength characteristics of the concrete were evaluated by conducting Compressive strength test, Splitting Tensile strength test and Flexural strength test. The compression strength test were conducted for 7days and 28days of curing and split tensile strength test and flexural strength test were conducted for 28days of curing on a M25 grade concrete. The mix proportion M25 was found to be 1:1.36:2.71.The test results proved that the compressive strength, split tensile strength and flexural strength of concrete mixtures containing GGBS and Fly ash increases as the amount of GGBS and Fly ash increase. After an optimum point, at around 9% of GGBS and 40% of Fly ash of the total binder content, the further addition of GGBS and fly ash does not improve the compressive strength, split tensile strength and flexural strength.