One part alkali-activated materials for construction - A review

Abstract

With the present-day call for sustainability in concrete constructions, alkali-activated materials (AAM) - both mortar and concrete mixes, are attracting immense interest owing to their enhanced strength and durability characteristics, and lower environmental impact. However, the utilization of the conventional two-part AAM's is generally restricted to precast sector, primarily due to the inherent difficulties associated with the transporting, storage, and handling of alkaline activator solutions which are generally aggressive in nature. This has led to the development of one-part type (or "Just add water"- type) geopolymers in which liquid activator solution is replaced with a solid or anhydrous activator. The performance of a one-part geopolymer is significantly influenced by the type of aluminosilicate precursors and solid activators used. Notably, in most of the studies, fly ash and/or GGBFS are used as the precursors, while any of anhydrous sodium silicate, sodium hydroxide, sodium carbonate, calcium hydroxide, and sodium metasilicate is used as the activator. This review article discusses the various studies that have focused on the production and placement, and the fresh, and hardened properties of one-part alkali-activated materials. Various issues associated with efforts to make such binder systems more amenable also to cast-in-situ applications are addressed. © 2023 Elsevier Ltd. All rights reserved.