Sustainable Marine Structures

Marine infrastructure is increasingly vulnerable to harsh environmental conditions that accelerate the degradation of traditional materials such as Portland cement concrete and carbon steel. This review systematically investigates recent advancements in sustainable alternatives, including geopolymer concrete, engineered cementitious composites (ECC), bio-concrete, fiber-reinforced polymers (FRPs), and bamboo, stainless steel, and steel-CFRP hybrid bars. Each material is evaluated based on marine durability, mechanical performance, environmental impact, and cost feasibility using life cycle assessment, durability modelling, and a multi-criteria decision-support framework. The results reveal that geopolymer concrete and FRP reinforcement’s exhibit superior corrosion resistance and environmental benefits, while ECC and steel-CFRP composites offer structural resilience with moderate environmental trade-offs. However, challenges remain in long-term performance validation, standardization, and market integration. The review concludes that a combined approach involving innovative materials, computational tools, and sustainability assessment is essential for advancing marine infrastructure. Outlook recommendations include focused field studies, development of regulatory guidelines, and interdisciplinary collaboration to drive the practical adoption of eco-efficient materials in coastal and offshore construction.