Cementitious composites in aquatic environments, evaluation of fracture and mechanical behavior in long-term submerging in fresh and saltwater, and simulated splash zone conditions

Aquatic environments can be severely harsh, so structures need suitable materials to endure them. Among the materials promising for aquatic environments are cementitious composites; however, their ability to withstand degrading environments should be evaluated. This study aims to evaluate cementitious composite's mechanical and fracture behavior with seven mix designs in three aquatic environments submerged in fresh and saltwater and exposed to a simulated offshore tidal-splash regime. Environmental exposure durations were chosen as 28, 90, and 365 days. Cementitious composites were developed with glass, PVA, and PP fibers. The results show materials with different behaviors, from fully brittle (without fiber) to strain-hardening (made of PVA and PP fibers). In the simulated splash zone environment, up to 25% strength degradation is seen in the most severe conditions. Among the parameters, fracture indexes are reduced more severely. The failure patterns were investigated, some SEM photos were presented, and some statistical evaluations (including trends and correlations) were presented.