A cooperation among road authorities in Finland, Norway and Sweden has created a new Nordtest method NT BUILD 515 for hydrophobic impregnation of concrete. The road authorities of the Nordic countries allocate, yearly, vast sums on the hydrophobic surface protection of reinforced concrete structures (e.g. bridges) in order to reduce the risk for chloride induced corrosion, caused by the extensive use of de-icing salts during harsh winters or sea water ingress.
The harmonized standard EN 1504-2 (CEN, 2004) is the basis for CE-marking and declaration of performance of hydrophobic impregnation systems, but the property “diffusion of chloride ions” is, according to the standard, “subject to national standards and national regulations”. This means that the same CE-marked product needs to meet different requirements regarding this property, which are imposed by the local authorities. Such requirements are based on different local test methods. Thus in Sweden, Finland and Norway the requirements today based on three different test methods, one for each country. Therefore, the Swedish Transport Administration (Trafikverket), the Finnish Transport Agency (Liikennevirasto) and the Norwegian Public Roads Administration (Statens Vegvesen), have initiated this project resulting in a new method (NT BUILD 515) for testing hydrophobic impregnations for concrete, with regard to prevention of chloride ingress. The background documented in the NT TEC report 620 with the same name. Both is downloadable free from this site.