Protection of reinforced concrete by coatings and corrosion inhibitors

The use of coatings (organic and inorganic) for the protection of reinforced concrete is widespread. The advantages of inorganic coatings are that they are stable in UV‐radiation, non‐combustible, do not foul and have a microcrystalline texture, while organic coatings have the advantage of low permeability of carbon dioxide, sulphur dioxide and water. The aim of the present work was to compare, in the presence of chloride ions, the performance of an acrylic dispersion and a silicate coating, when the latter was or was not combined with a corrosion inhibitor (N‐N’‐dimethylaminoethanol). The behaviour of the silicate coating was examined as its use is increasing due to environmental reasons and as it can be applied for the rehabilitation of old structures. Half‐cell potential measurements, mass loss and carbonation depth measurements, as well as chloride diffusion rate revealed that the acrylic dispersion provides better protection of reinforcing steel in concrete than the silicate coating, but the combination of the silicate coating with the corrosion inhibitor provides the best level of concrete protection.