Mechanical and durability properties of seawater sea-sand concrete: a review

Seawater sea-sand concrete (SSC) has attracted increasing interest for coastal and island construc- tion because it reduces dependence on freshwater and river sand. Its main limitation is durability, particularly chloride-induced reinforcement corrosion caused by the direct use of seawater and sea sand. This review summarizes current research on the raw materials, fresh properties, mech- anical behavior, and durability of SSC. Existing studies show that seawater ions modify hydra- tion and pore development. SSC commonly exhibits accelerated early hydration, higher early-age compressive strength, reduced workability, shorter setting time, and increased yield stress and plastic viscosity. Improvements in tensile properties and elastic modulus are less consistent. The main durability concern is chloride-related corrosion, while carbonation, freeze-thaw damage, and coupled long-term degradation remain insufficiently understood. SSC performance is gov- erned primarily by binder composition, water-to-binder ratio, sea-sand quality, and reinforcement type. Although supplementary cementitious materials and corrosion-resistant reinforcement can improve performance, long-term evidence and unified evaluation