Experimental study on geopolymer concrete using metakaolin and bottom ash

Abstract

Ordinary Portland cement is the most popular binder material for producing concrete. The usage of cement is ever increasing due to its ability to gain early strength as well as prolonged strength gain. However, it is energy intensive and also consumes large amount of natural materials for its production. Further, production of every one ton of cement releases about 1 ton of CO2 in to atmosphere promoting global warming and deterioration of ecosystem. More so, the performance of concrete in terms of durability is also a major concern when exposed to aggressive environment. The development of geopolymer concrete (GPC) is an important newlinestep towards the production of eco-friendly concrete. It is an inorganic alumina-silicate compound synthesized from geological material or industrial by-products such as fly ash, slag, GGBFS, rice husk ash etc. The effective usage of industrial by-products can address the environmental pollution issues. Also, the geopolymer concrete is expected to be more durable than conventional concrete due to the absence of Ca(OH)2. Hence an attempt has been made in the present work to study the effect of the blend of metakaolin(MK) and bottom ash (BA) as source material on the performance of GPC. The materials such as meta-kaolin (MK), bottom ash (BA), fine aggregate, coarse aggregate, sodium hydroxide, sodium silicate and cement have been used in the present work to make geoplolymer mortar (GPM), newlinegeopolymer concrete (GPC) and control concrete. Several trial mixes have been made to arrive at the optimum mix proportion for GPM to impart maximum strength. Further, the GPC mix proportion was made based on the GPM mix with maximum strength and also the guidelines prescribed by Rangan. The specimens of GPM and GPC were cast and cured at ambient temperature. Also, M 30 grade control concrete was made using OPC and cured in water. The GPC and control concrete specimens were tested for compressive, split tensile, flexural strength and modulus of elasticity. newline newline