In a world grappling with freshwater scarcity, a novel approach to concrete production is making waves—quite literally. Researchers are exploring the use of seawater in concrete mixing, a sustainable solution that could revolutionize construction in coastal and marine environments. At the forefront of this research is Iman Aghajanzadeh, an assistant professor at the University of Miami’s Department of Civil and Architectural Engineering. Her recent study, published in the journal *Applied Ocean Research* (translated from Latin as “Applied Marine Research”), delves into the durability properties of seawater-mixed concrete, offering insights that could reshape the future of coastal infrastructure and the energy sector.
Aghajanzadeh’s study, a systematic review of existing research, reveals that seawater can accelerate the early hydration of ordinary Portland cement (OPC). This is due to the ionic activity of chloride, sodium, and magnesium ions, which lead to a denser early-age microstructure and enhanced initial strength. “Seawater’s unique ionic composition can actually benefit the early stages of concrete setting,” Aghajanzadeh explains. “However, the long-term effects are more complex and vary based on several factors.”
The study highlights that while seawater-mixed concrete generally exhibits improved sulfate resistance, its carbonation behavior and susceptibility to alkali-silica reaction (ASR), shrinkage, and freeze-thaw damage are inconsistent across studies. These variations are influenced by curing conditions, ionic composition, and mixture design. The incorporation of supplementary cementitious materials (SCMs) like metakaolin, fly ash, and ground granulated blast-furnace slag can enhance chloride binding and refine the microstructure, mitigating some adverse effects.
For the energy sector, these findings are particularly significant. Coastal and offshore wind farms, desalination plants, and other marine infrastructure require durable, sustainable construction materials. Seawater-mixed concrete could offer a cost-effective, eco-friendly alternative to traditional concrete, reducing the demand for freshwater and potentially lowering construction costs.
However, the path forward is not without challenges. Aghajanzadeh emphasizes the need for standardized methodologies and data-driven investigations to optimize seawater-mixed concrete for widespread use. “We need more long-term studies to fully understand the durability aspects,” she says. “This will help us develop guidelines and standards for using seawater in concrete production.”
The commercial implications are substantial. As the world shifts towards renewable energy and sustainable construction, the demand for innovative materials is growing. Seawater-mixed concrete could play a pivotal role in this transition, offering a sustainable solution that aligns with global environmental goals.
In conclusion, Aghajanzadeh’s research opens up new possibilities for the construction industry, particularly in coastal and marine environments. By harnessing the power of seawater, we can conserve freshwater resources and build more sustainably. As the energy sector continues to evolve, the adoption of seawater-mixed concrete could be a game-changer, driving innovation and sustainability in construction.