
Background:
The durability of concrete structures is particularly difficult to estimate under aggressive environments, where the number and width of the cracks has a significant influence. Project ReSHEALience (Rethinking coastal defence and Green-Energy Service infrastructures through enHancEd-durAbiLIty high-performance fiber reinforced cement-based materials, nº760824) consisted in the development of a Durability Assessment-based Design (DAD) methodology for structures, to improve durability and predict their long-term performance under extremely Aggressive Exposures (EAE: XS-chloride induced corrosion, XA-chemical attack). For more information, visit the official webpage of the project (www.uhdc.eu).
Why to use UHPC?
UHPC has an extremely high performance under aggressive exposure environments. This also includes the cracked state, as the high fiber content limits the crack width even up to a significant strain in the structure. The ReSHEALience project tried to add new functionalities to UHPC, particularly to promote the self-healing of the microcracks with nanoconstituents added to the concrete matrix. This is especially interesting for marine structures, geothermal/biomass energy plants due to their severe conditions under operation.

Advantages:
- Induced self-healing is particularly efficient when the crack width is reduced, as happens in the UHPC under service.
- A more accurate estimation of the durability is particularly relevant for the cradle to grave assessment of structures, helping to take the most appropriate decision in the planning stage.
Achievements:
- Six different pilots (TRL6-7) were built during the project with advanced concrete technologies.
- The remote monitoring of the durability installed is active after the project (finished in March 2022) and it is showing the higher performance of the UHPC even under cracked state compared to the uncracked reference concrete.