ABSTRACT
There are two principal types of treatment. Coatings/sealers rely upon the formation of a pinhole-free film of finite thickness over the concrete surface, which can act as a barrier to the diffusion into concrete of CO2 and/or solutions. Those materials described as
sealers claim some penetration into the pores of the concrete. Coatings would normally have a dry film thickness of 150-500 µm, although thicker ‘high-build’ coatings are also used. Pore-lining treatments are hydrophobic materials which line surface pores of the concrete and repel moisture. The most widely used materials are commonly called silanes, a term which embraces monomeric silane and oligomeric siloxane formulations. Whilst among coating materials both anti-carbonation and anti-water/chloride treatments can be found, the pore-lining materials are not effective as anti-carbonation coatings, only for keeping water/chloride out.
