Development of Fly Ash based Geopolymer behaviour of Fly Cement

Geopolymer is a novel binding material produced from the reaction of fly ash with an alkaline activator liquid; ensure durability and environmental sustainability and is emerging greener alternative to Ordinary Portland cement in the construction field. In this research, the influence of various parameters on the consistency and setting times of low-calcium fly ash-based geopolymer cement under varied heat curing temperature were investigated. Systematic trials were carried to optimise the normal consistency and setting times over a number of parameters. The consistency of the geopolymer cement does not show any variation when mixed with different combinations of alkaline activator solution; whereas the setting times were observed to be dependent on the concentration of NaOH solution, ratio of alkaline activator liquid and variation in temperature. The test results revealed that the normal consistency of the fly ash-based geopolymer paste is found to be at 28% of alkaline activator solution for all the selected mixtures. Wherein, increase in concentration of NaOH solution increases setting times; increase in alkaline liquid ratio decreases setting times up to certain limits viz; increase in alkaline liquid ratio from 1.5 to 2.0, decreases setting times; further increase in alkaline liquid ratio from 2.0 to 2.5, increases setting times. The setting times were observed as decreased when the alkaline liquid ratio increased from to 2.5 to 3.0. Keywords: Geopolymer, alkaline activator, consistency, setting times