Experimental investigations on mechanical properties of geopolymer concrete composites

Abstract

Due to growing environmental concerns of the cement industry, alternative cement technologies have become an area of increasing interest. It is now believed that new binders are indispensable for enhanced environmental and durability performance. Geopolymer concrete (GPC) is an innovative method and is produced by complete elimination of ordinary Portland cement by fly ash. Geopolymer concrete has two limitations such as delay in setting time and necessity of heat curing to gain strength. Present research aimed to rectify these two limitations of GPC by replacing 10% of fly ash by OPC on mass basis. This paper presents the results of an experimental investigation on the mechanical properties of Geopolymer Concrete Composites (GPCC) containing 90% Fly ash (FA), 10% Ordinary Portland Cement (OPC) and alkaline liquids. The study analyses the impact of replacement of 10% of fly ash by OPC in the GPC mix on the mechanical properties such as density, Compressive Strength, Split Tensile strength and Flexural strength both in ambient curing at room temperature and heat curing at 60o C for 24 hours in hot air oven. Mixtures were prepared with alkaline liquid to fly ash ratio of 0.4. Based on the test results, empirical expressions were developed to predict split tensile strength and flexural strength of GPC as well as GPCC in terms of their compressive strength.