Seawater concrete: A critical review and future prospects

Concrete production requires a large amount of water which causes a shortage of natural freshwater. Conversely, seawater in concrete can improve sustainability in construction by reducing the excessive consumption of natural freshwater. In the literature, the use of seawater in concrete still has a controversial reputation. It is, therefore, crucial to understand the properties of concrete mixed and cured with seawater. The past and recent research on seawater concrete is thoroughly reviewed in this paper and identifies the significant differences in characteristics between seawater concrete and conventional concrete. Existing studies indicate that high chlorides in seawater enhance the hydration rate, shorten the setting time and increase the early strength of concrete. In order to lessen the effect of chlorides and increase the durability of seawater concrete, mineral admixtures, retarders, and superplasticizers have been recommended. Past studies have also revealed that the use of seawater in concrete will inevitably corrode steel bars. This article covers the advantages and disadvantages of adopting FRP and stainless steel bars to prevent the corrosion of steel reinforcement caused by seawater. It also suggests future possibilities of using natural and recycled aluminum reinforcement in seawater concrete which not only protects concrete from corrosion but also leads to the sustainability of concrete. Overall, the outcomes of this study will contribute to further research aimed at improving the properties of seawater concrete.