Role of Alkaline Activator in Development of Eco-friendly Fly Ash Based Geo Polymer Concrete

Abstract

Ordinary portland cement (OPC) is conventionally used as primary binder to produce concrete. The amount of carbon dioxide released during the manufacture of OPC and the extent of energy required to produce OPC are the matters of environmental concern in view of global warming and the poor availability of power. Fly-ash, abundantly available byproduct of coal fired thermal power stations is posing great environmental problems through its disposal. Fly ash with combination of alkalis like sodium hydroxide and sodium silicate can produce binding material depending upon the characteristics of these ingredients. The possibility of eco-friendly use of locally available fly-ash with commercially available alkalis in the development of effective binder; and the effect of various parameters on the compressive strength of geo-polymer concrete is explored in the present paper. The laboratory investigations under ambient and oven dry curing conditions suggested that locally available low calcium fly-ash is suitable for development of geo-polymer concrete; and the compressive strength of geo-polymer concrete is a function of mass ratio of alkaline liquid to fly-ash, mass ratio of sodium silicate to sodium hydroxide and molar concentration of sodium hydroxide.