Shrinkage Mechanisms and Mitigation Methods of Alkali Activated Materials

Shrinkage of cementitious material refers to the phenomenon of volume reduction. This chapter provides a detailed review of the shrinkage behavior and mechanism of AAMs, with autogenous and drying shrinkage as the most prominent. Influencing factors such as precursor composition, alkali activator properties, and curing conditions are discussed, emphasizing their role in controlling shrinkage behavior. Advanced shrinkage mitigation strategies are reviewed, including the use of chemical admixtures, nanoparticle incorporation, and modified curing techniques. The need for improved predictive models for AAM shrinkage is highlighted, as current models for OPC are inadequate for accurately forecasting AAM behavior. The chapter concludes by emphasizing the importance of further research in developing sustainable solutions to control shrinkage in AAMs, thereby enhancing their viability in large-scale construction applications.