Alkali-activation of fly ash: Performances and potential industrial applications

This chapter provides discussion of the physicochemical properties of raw fly ash, its effects on the mechanical properties and the durability of alkali-activated fly ash, and what implications these properties possess for the potential industrial applications. Recent advances in analytical tools and techniques have enabled the characterization of raw fly ash on the fundamental atomic scale. Understanding the raw material properties of fly ash is crucial for the formulation of alkali-activated fly ash. Previous studies reporting experimental results pertaining to the mechanical properties and durability of alkaliactivated fly ash are extensively revisited and discussed with insight from the microstructural properties of geopolymer gel. Owing to outstanding performances and functionalities, alkali-activated fly ash has provided a number of potential industrial applications. These may include fire-resistant materials and the solidification/stabilization of hazardous toxic wastes, as well as construction materials of which exceptional durability, outstanding mechanical properties, and low CO₂ emission are highly desirable. The progress of alkali-activated fly ash from a materials science standpoint is reviewed to suggest their potential in industrial applications.