Effects of Mineral Admixtures, Water Binder Ratio and Curing on Compressive Strength of Concrete

Abstract

Considerable research has focused on the effect of mineral admixtures on concrete during the past two decades. Suitable addition of mineral admixtures like fly ash (FA), silica fume (SF), metakaolin (MK) etc., in concrete improves strength and durability characteristics of concrete. This paper presents the laboratory investigation on the effects of mineral admixtures and water binder ratio on compressive strength is discussed. The study was conducted for three different mineral admixtures namely; FA, SF and Mk with different water cement ratios of 0.32, 0.35, 0.4 and 0.5. The admixture proportion varies from 0 to 15% with an increment of 5% for SF and MK and 10 to 30% with an increment of 10% for FA. The compressive strengths were determined at the age of 3, 7, 14, 28 and 90 days with and without admixture and a comparative study was also made. From the results it is concluded that FA based concrete offered more strength for lower water cement ratios (0.32 & 0.35) and MK modified concrete showed greater strength for higher water cement ratios (0.4 & 0.5). The strength enhancement of SF concrete was more or less similar for all water cement ratios. The outcome of this research work provides an optimal and economical mix for better strength.