Abstract
An increasing number of offshore renewable energy devices using concrete material are currently being developed and installed, for instance substructures for floating offshore wind turbines (XCF by MAREAL, Hywind Tampen by Equinor, SATH by SAITEC, Damping Pool by BW IDEOL, etc.). Concrete structures present the advantages of competitive manufacturing, operation and maintenance costs, high durability and a strong local content. They are particularly suitable for serial production.
However, concrete structures are usually reinforced with steel rebars that are prone to corrosion, in particular in offshore environment. The reinforced concrete structures can be protected against corrosion by cathodic protection (sacrificial anodes, impressed current), increased concrete cover, specific coatings, etc. These protective measures lead to additional costs, increased material quantities and potential environmental impacts.
Within the Ocean Power Innovation Network (OPIN), a Collaborative Innovation Group (CIG) has been set up to explore opportunities (alternative rebar materials, specific concrete formulations, etc.) to reduce the cost of corrosion and increase the lifetime of reinforced concrete structures in offshore renewables applications.
The main objective of this CIG was to identify one or several future R&D collaboration opportunities within the CIG members(all or a subset) and start preparing the basis for associated grant applications. A state-of-the-art report has been prepared to support this final goal, collecting inputs from all CIG members on the activities identified in Table 1.
The present report is not a comprehensive, international state-of-the-art study. The aim was to share knowledge, information and ideas amongst the CIG members. This information was collected by means of written contributions, online workshops, surveys, etc. All CIG members were invited to provide content for all activities relevant to their competencies.