Alkali-Activated Concrete Workability and Effect of Various Admixtures: A Review

Alkali-activated concrete (AAC) is getting popular as a sustainable alternative for ordinary Portland cement concrete. Hence, questions regarding potential adaptation for existing concrete technologies to deal with performance issues of the new concrete type were raised. On top of these technologies, the efficiency of various admixtures and their interactions with the AAC's ingredients, hydration products, and microstructure development represent a knowledge gap. This paper reviews the workability requirements for AAC and the efficiency of various admixtures to achieve the targeted performance. The stability of admixtures in the alkaline medium, optimum dosages, and interaction with the activation process was highlighted. The reported data are anticipated to guide engineers in selecting suitable admixtures to achieve the desired workability while maintaining adequate performance.