Norwegian Bridges
The Norwegian Public Roads Administration (NPRA) has specified TSZ duplex coatings for protection of coastal steel bridges since 1965. These bridges are exposed to harsh corrosive saltwater environments and road de-icing salts. Some of these Metal Sprayed coatings have lifetimes of over 40 years to first maintenance. The Metal Sprayed coating is topcoated with paint to provide the duplex coating to give both barrier and sacrifical corrosion protection, as well as aesthetic appeal.
The Norwegian Public Roads Administration (NPRA) introduced thermally sprayed zinc (TSZ) duplex coatings for coastal steel bridges in 1965 and for all bridges in 1977, replacing red lead coatings. Click Here to find out more.
The Rombak Bridge was coated in 1970 with a duplex coating of TSZ coating of 100 μm and two layers of alkyd paint at 100 μm each. It is a 750m suspension bridge with a bolted truss work under the bridgeway. The first preventative coating maintenance was completed in 2012 by washing and applying of the paint top coat which was subject to partial flaking, the TSZ coating however was still in perfect condition.
