Estimation of Compressive Strength of Concrete by testing the Pozzolanic Reactions of Blended Cement Mortars using Bolomey’s Equation

Abstract

To experimentally investigate the effect of the presence of Supplementary Cementitious Materials (SCMs) in concrete strength gain by using the efficiency factors in Bolomey’s equation to the cement mortar. The quaternary blended cement mortar consists of Fly ash (FA) at 0, 20 and 30%, micro silica (SF) at 0, 5 and 10% and Nano silica (NSF) at 0, 2, 3 and 6% replacement to cement. To study the compressive and flexural strength of mortars a total of 63 mortar mixes, with a cement-sand ratio of 1:2.75 were cast and tested; out of these mixes, 27 were variable w/b ratios based on consistency and remaining 36 were with fixed w/b ratio of 0.485. The mixes using SF and NSF had shown an improved performance while FA at 20% optimum indicated strength on par with the control mix. In triple blended mixes, all the combinations of NSF-SF, NSF-FA and SF-FA improved the performance of mortar. Bolomey’s equation was used to find the Efficiency of SCMs in mortar and concrete mixtures. Concrete mixes with two different cement contents along with a confirmation test using another cement quantity were carried out to identify optimum proportions of quaternary blended mixtures.