Biofouling on cementitious materials: Durability challenges across different exposure zones in marine environments

Abstract

Investigating the durability challenges related to biofouling on cementitious materials in marine environments is crucial. The presence of micro- and macro-organisms in seawater creates favourable conditions for the colonization of cementitious materials, further complicating their performance over time. Therefore, this study investigates the influence of biofouling on plain concrete and reinforced concrete (RC) using CEM I and CEM V cement types in submerged and tidal exposure zones of a real marine environment, in Banyuls-sur-mer, France. Irrespective of the cement type, the microstructural analysis of submerged concrete revealed the development of biomineralized serpulid tubes on its surface. With respect to RC systems, both with and without galvanic cathodic protection (using aluminium anode) in the tidal zone, the half-cell potential (HCP), mixed potential, and protection current were continuously monitored upto 95 days. Furthermore, the effect of biofilm on RC surfaces and water levels was assessed, emphasizing the role of biofilm as a physical barrier that limits oxygen diffusion and significantly influences the corrosion characteristics of the embedded steel. Building on these findings creates synergy in developing ecologically durable materials that increase ecosystem functionality and strengthen the infrastructure resilience.