Bioreceptivity of cementitious materials in seawater: mechanisms, acting factors and consequences; Bioreceptivity of cementitious materials in seawater: Mechanisms, Acting Factors and ConsequencesFrenchEnglish

International audience ; Concrete is a complex composite material; whose different components allow it to adapt to very different uses due to its physicochemical characteristics adaptable to very varied conditions. Its mechanical performance, exceptional durability and moderate cost explain the wide use of this material in the construction of marine structures. Submerged in the marine environment, the concrete will be colonized by various marine organisms that gather together on the surface in their sessile form called biofilm/biofouling. This colonization is the starting point for different biological interactions that may occur between the material and its marine environment (biodeterioration/bioprotection). The cycle and the rate of colonization will depend on environmental conditions such as the nature of the substrate (composition, physicochemical properties of the support, etc.) as well as the properties of the concerned microorganisms. In order to study the bioreceptivity of concrete in the marine environment, this paper focuses successively on the characteristics of the marine environment that affect the colonization of the concrete and the concerned organisms. Then, the intrinsic parameters of concrete that can influence bioreceptivity are listed and described. The same goes for the mechanisms leading to the biofilm formation and the biocolonisation of concretes. Finally, the subject of the positive (bioprotection) or negative (biodeterioration) effect of the biofilm formation on concrete is discussed. ; Le béton est un matériau composite complexe, dont les différents composants lui permettent de s’adapter à des usages très différents grâce à ses caractéristiques physicochimiques adaptables à des cahiers des charges très variés. Ses performances mécaniques, sa durabilité exceptionnelle et son coût modéré justifient l’utilisation large de ce matériau dans la construction des ouvrages maritimes. Immergé dans l’environnement marin, le béton est susceptible d’être colonisé par les différents organismes ...