Effects of curing environment on strength and microstructure of alkali-activated fly ash-slag binder

This paper delineates the influence of curing environment on strength and microstructural growth in alkali-activation of fly ash-slag. The strength properties of fly ash-slag binder cured under different temperatures and humid conditions were evaluated. Further, the development of strength in autoclave and microwave cured specimens were studied. An investigation was done to understand the strength development in short and long duration curing. Microstructural analysis was also made to correlate the reaction products with the observed strength. Results revealed that a higher curing temperature favored a better strength development in fly ash rich samples whereas slag rich samples developed micro cracks; particularly for unsealed conditions in dry curing environment. Autoclaving pressure and microwave radiation curing showed high strength development in the early stages of curing due to the faster development of reaction products. The major reaction products were the hydrates of calcium/sodium based alumino-silicates. (C) 2019 Elsevier Ltd. All rights reserved.