Durability and damage resistance of sustainable Portland limestone cement-based (ultra) high-performance concrete in seawater

Coastal communities often rely on conventional reinforced concrete infrastructure to offer protection from the marine environment. However, these structures are highly susceptible to chloride-induced corrosion, compromising their durability. Ultra-high-performance concrete (UHPC) offers superior durability, but faces adoption barriers due to rigid design requirements and high costs, largely driven by steel fiber reinforcement. Recent advances in fiber technology and the development of greener cementitious materials created opportunities for alternative, sustainable, and cost-effective UHPC designs that could significantly enhance coastal infrastructure resilience, particularly as climate change intensifies natural hazards. However, data on the mechanical and long-term performance of such UHPC in harsh environments remain limited. This study investigates the durability and damage resistance of sustainable UHPC mixtures based on Portland limestone cement (PLC), incorporating high volumes of fly ash and slag, and reinforced with steel and polyethylene fibers. Specimens were exposed to seawater for up to 550 days and compared to a commercial UHPC. Evaluations included mass variation, electrical resistivity, ultrasonic pulse velocity, compressive strength, water sorption, thermogravimetric analysis, and resistance to chloride ingress and carbonation. Results indicate that the laboratory-developed UHPC mixtures, whether damaged or undamaged, exhibited excellent resistance to marine exposure, showing limited degradation, and performing comparably to the commercial UHPC. No significant chloride ingress or carbonation was observed in any mixture, regardless of fiber type.

The online version contains supplementary material available at 10.1617/s11527-025-02824-5.