Ecology, Environment and Conservation Paper

DURABILITY STUDIES ON GEOPOLYMER MORTAR UNDER HEAT CURING CONDITION

V. Sreevidya, R. Anuradha, Tini Thomas, and R. Venkatasubramani

Abstract

Geopolymer is a novel binding material produced from the reaction of industrial by-products containing silicate materials like fly ash, silica fume, metakaolin, ground granulated blast furnace slag etc with an alkaline solution. The present paper deals with the durability studies of Fly ash-based geopolymer mortar. With silicon and alumina as the main constituents, Fly ash has great potential as a cement replacing material in mortar. The replacement of Portland cement with fly ash is considered by its promoters to reduce the greenhouse gas “footprint” of concrete, as the production of one ton of Portland cement produces approximately one ton of CO2 as compared to zero CO2 being produced using existing fly ash. New fly ash production, i.e., the burning of coal, produces approximately twenty to thirty tons of CO2 per ton of fly ash. Since the worldwide production of Portland cement is nearly 2 billion tons, replacement of any large portion of this cement by fly ash could significantly reduce carbon emissions associated with construction. The mortar made with such industrial waste is eco- friendly. Sodium hydroxide and Sodium silicate solution were used as alkali activators. The ratios between solution (NaOH, Na2SiO3 solution and water) to Fly ash were 0.376, 0.386, 0.396 and 0.416 by weight. The heat curing method was adopted in this study. The results obtained from this study indicated that the geopolymer mortar specimens are highly resistant to acids.