5. General conclusions

Although the general properties of concrete surfaces are already well-documented, it is important to emphasize that they are linked in particular to the concrete placement process. The interdependence between concrete surface properties and formwork and/or stripping agents has thus been at the root of the first major series of functionalizations tested over many years, aimed primarily at making concrete less stainable. This type of functionalization, whether designed to make the concrete surface hydrophilic or hydrophobic, or to reduce its water absorption capacity, is beginning to be used on a large scale. Another family of functionalization has emerged more recently (in the last two decades or so) and involves incorporating depolluting fillers (mainly photocatalytic TiO ₂ or activated carbons) within the concrete, in order to contribute to...