A Study on Strength and Durability of Fly Ash–Metakaolin Blended Geopolymer Concrete

Abstract

Production of cement causes 8% of the total carbon dioxide emissions in the world. Finding a right alternative to cement is the need of the hour, to eliminate environmental pollution caused by cement production. A substitute for conventional concrete can be industrial waste products like GGBS, Flyash, Metakaolin, and so on, these mineral admixtures can be used to fully replace cement with some activators this mix of mineral admixtures and activator solution is called as geopolymer concrete. The current investigation presents the effect of metakaolin (MK), a by-product of kaolinite on Class F fly ash-based GPC. External exposure curing has been adopted, Influence of molarity on compressive and tensile strength and water absorption and sorptivity tests of GPC is tested for 8M, 10M, and 12M. Fly ash in GPC has been replaced with metakaolin at the 0%, 10%, 20%, 30%, 40%, and 50% for improvement of early age properties of concrete. Also, tests on fresh concrete like slump cone test are performed. Compressive strength was found at the age of 28 days on hardened concrete. At 28 days, there has been a 11%, 15%, 20%, and 38% increase in strength for 10%, 20%, 30%, 40%, and 50% inclusion of metakaolin compared with the control specimen of 0% MK inclusion. For upto 30% replacement of MK, the 28-day characteristic strength was observed to be higher than what it is designed for the water absorption.