Feasibility assessment and application of sea sand in concrete production: A review

The conventional preparation of concrete excessively consumes river sand, minerals, and freshwater resources, contradicting the principles of sustainable development. Due to the scarcity of freshwater and river sand resources, the use of seawater and sea sand as alternatives for concrete casting has garnered widespread attention worldwide. This paper provides a summary and critical review of the latest research on Seawater Sea Sand Concrete (SWSSC). Various performances of SWSSC, including the physicochemical composition, workability, mechanical properties, and durability of sea water and sea sand, are evaluated. Existing studies indicate that the material characteristics of sea sand significantly impact the performance of SWSSC and are a crucial factor in determining whether it can serve as a substitute for river sand in concrete. These characteristics include the particle size and content of harmful substances, such as coarse shells and organic matter in sea sand. Robust evidence suggests that when the particle size of shells in sea sand is less than 4.75 mm and the substitution range of sea sand in concrete meets conditions like 20%- 40%, sea sand has minimal negative effects on the mechanical properties of concrete, and it may even offer prospects for accelerating cement hydration, improving pore structure, and enhancing durability compared to ordinary concrete. Moreover, the higher chloride content in seawater and sea sand can shorten the service life of concrete structures. This issue can be addressed by adding high-alumina auxiliary cementitious materials or employing measures such as Fiber-Reinforced Polymer (FRP) reinforcement. Finally, the study emphasizes the applicability, limitations, and potential challenges of using SWSSC, including the extraction of sea sand. This research lays the foundation for the effective utilization of seawater and sea sand in concrete for sustainable development.