Performance of Fly Ash Geopolymer Mortar Containing Clay Blends

The current study presents an experimental investigation on the mechanical, microstructural, and durability characteristics of Class F fly-ash-based geopolymer mortar containing locally available waste clay as source material. Principles of response surface methodology were used for the optimization of clay. Two types of waste clay collected from different sources in their raw state and calcined form (after thermal treatment) were considered for the investigation. The maximum compressive strength obtained was at 20% clay content. The results reveal the suitability of waste clay with and without heat treatment in developing geopolymer binder. Geopolymer mortar containing calcined clay exhibited better strength and durability performances. Bond strength of the binder with the concrete substrate was improved by using calcined clay (38 to 42%). © 2022 American Concrete Institute. All rights reserved.