Use of supplementary cementitious materials in seawater–sea sand concrete: State-of-the-art review

The use of supplementary cementitious materials (SCMs) in seawater–sea sand concrete (SSSC) enhances the concrete performance as well as helps in reducing the excessive consumption of natural resources—this aspect is very important for promoting green and sustainable development in the construction industry. This research involved a comparison and analysis of the performances of SCM-containing and ordinary SSSCs as well as a review of the mix proportions and related parameters of SCM-containing SSSCs. The effects of SCMs on SSSC characteristics, such as workability, mechanical properties, hydration, microstructure, and durability, were also investigated. In addition, some special SCM-containing SSSCs were introduced, and their engineering application status and limitations were evaluated. The available evidence indicates that the substitution rate, type, and characteristics of SCMs affect the mix-proportion design of SSSCs, in turn substantially influencing their workability and mechanical properties. The use of SCMs reduces the exothermic peak of hydration of SSSCs, thereby widening their engineering applications. Furthermore, SCMs can work in conjunction with SSSCs to promote the formation of hydration products, resulting in a more refined microstructure. The incorporation of SCMs considerably improves the resistance of SSSCs against chloride and sulfate corrosions, ultimately reducing the risk of traditional steel corrosion. Moreover, based on the conclusions drawn from existing studies, this study proposes relevant future research directions to promote further application of SCMs in SSSCs. The aim of this review is to improve our understanding of the mechanism through which SCMs influence SSSC performance and to establish a solid foundation for expanding the applications of SCMs toward achieving sustainable high-performance SSSCs.