Alkali-activated slag cement and concrete: a review of properties and problems

This paper summarizes the advantageous and disadvantageous properties of alkali-activated slag cement and concrete by reviewing previously published work in English, Russian and Chinese. Practical problems and theoretical questions are discussed. Topics for future work in this field are suggested. The practical problems mentioned are quick setting, the possibility of alkali-aggregate reaction, and the occurrence of efflorescence, shrinkage, microcracks and strength variation. The theoretical questions discussed concerning alkaline activation include the roles of the alkaline anion and cation, the nature of the hydration products, microstructural development and the setting and hardening mechanisms.