Reshealience project completed
The project Reshealience (“Rethinking coastal defence and green-energy Service infrastructures through enHancEd-durAbiLity high-performance cement based materials”, H2020 760824), funded within the European H2020 Program, has been completed in March 2022, after more than 4 years of work since January 2018.
During this time Rover Maritime has focused its efforts on the development and validation of ultra high durability concrete (Ultra High Durability Concrte UHDC) exposed to harsh environments, such as the marine environment. For this validation, a pilot structure was developed and installed at the Port of Sagunto whose corrosion behavior has been monitored since January 2021. The structure reproduces the application that UHDC material would have on a floating concrete platform intended for building offshore wind turbines (https://uhdc.eu/pilot4-rover-xs-trl6/).
During the final project meeting, in addition to a final review of the work and objectives of the project by representatives of the European Commission, the consortium members had the opportunity to visit the two pilots of the project installed in Valencia. One of them is that of Rover Maritime, and the other, developed by the company RDC and installed in the port of Valencia, consists of a bat for the breeding of mussels built with prefabricated beams based on UHDC.
Main project results
Ultra high performance concrete, UHPC (Ultra High Performance Concrete) or UHPFRC (Ultra High Performance Fiber Reinforced Concrete), is a concrete with a high cement content and with metallic fibers (although they can also be polymeric) and silicon aggregates with a maximum size of 1 mm. This type of concrete, which is highly ductile, allows to design and produce complex shapes of great strength and at the same time very light and slender. Their high durability is based on the low porosity they possess and that prevents the entry into the matrix of aggressive agents.
In the Reshealience project, the UHDC (Ultra high durability concrete) concept was introduced, going one step beyond UHPFRC, since in addition to the usual components a number of additives for improving durability were used such as nanoalumina in dispersion and a crystal additive from the company Penetron. The UHDC used in the construction of the Rover Maritime pilot has a 28-day compressive strength of 133 MPa and a tensile strength of 9.02 MPa. Its porosity is around 4%, while the porosity of a conventional concrete is above 10%.
During the pilot’s exposure time in real environment, corrosion-related parameters (intensity and potential) have been monitored through a sensor system installed internally in the structure. The evolution of concrete fissures has also been monitored. The main conclusions drawn from the collected and analyzed data point to excellent material behavior in this environment.
On the one hand, most of the cracks identified in the pilot, located in the area with greater mechanical requirement, were fully or partially sealed during the monitoring period, highlighting the potential for self-healing of UHDC. This could be verified not only by observing the fissures themselves, but also in a way
Since, both the evolution of intensity and potential corrosion has been very positive. Currently, considering the values of these parameters, the pilot’s UHDC concrete does not show any signs of corrosion after almost 1.5 years of exposure.
According to all the results analyzed, it is confirmed that the behavior of UHDC in aggressive exposure conditions, such as the marine environment, is excellent, constituting an alternative with great potential in this type of environments to replace conventional concrete or steel, thanks to increased durability and service time and the reduction, almost to zero, of maintenance costs.
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