Effect of seawater use on the physical and mechanical properties of self-compacting concrete

This study examines seawater's impact on Self Compacting Concrete (SCC) properties in mixing or curing mediums. SCC samples following the European Federation of National Associations Representing for Concrete (EFNARC) standards were prepared using freshwater or seawater. Workability tests (Slump flow, L-Box, V-funnel) and hardened properties tests (compressive and splitting tensile strength) were conducted. Results showed a 12.32% slump flow decrease with seawater. However, T50 and V-Funnel tests revealed a 28.37% and 29.57% increase in time respectively for seawater mixes, indicating improved filling ability and lower viscosity. The L-Box test showed a 20.85% decrease in flow compared to freshwater mixes, demonstrating lower passing ability. At 56 days, compressive strength for SCC FF (Fresh water for mixing and curing), SCC FS (Fresh water for mixing and Seawater for curing), SCC SF (Seawater for mixing and Fresh water for curing), and SCC SS (Seawater for mixing and curing) was 26.00, 25.04, 25.60, and 25.68 N/mm2, respectively. Splitting tensile strength for SCC FF, SCC FS, SCC SF, and SCC SS was 2.44, 2.31, 2.53, and 2.34 N/mm2, respectively. Seawater reduces workability but enhances filling ability, density, compressive strength, and splitting tensile strength of SCC, particularly when used for mixing and curing. Seawater holds potential in SCC production, addressing freshwater scarcity and coastal environmental issues.