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

Abstract Seawater sea-sand concrete (SSC) has attracted increasing interest for coastal and island construction 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, mechanical behavior, and durability of SSC. Existing studies show that seawater ions modify hydration 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 governed 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 methods remain limited. Future work should focus on coupled deterioration mechanisms, performance-based mixture design, and standardized durability assessment for marine applications.