Hot dip galvanizing of bridge beams for long term corrosion protection: Fid-Bau Portal

Hot dip galvanizing of bridge beams for long term corrosion protection

Deacon, D. / Hopkins, A. / Smith, W.J.

This paper illustrates the galvanising process and gives an insight into the performance of galvanising as a corrosion protection system and outlines the benefits to maintenance engineers through the use of galvanising in bridge applications. Three case histories involving the use of galvanising for road and rail bridges are described. The first case history relates to the Stainsby Hall Bridge, a four span concrete and steel composite structure over the A19 trunk road in Middlesbrough in the north east of England. This case history is set out in detail. The other two case histories are the Burn Rew Bridge, which spans rail tracks, and the Lydlinch Bridge. The latter structure spans a small river and was erected in 1945. Both the Burn Rew and Lydlinch Bridges are in southern England. For two of the three maintenance is extremely difficult (and expensive) because it involves stopping traffic or trains. It cannot be said that maintenance of a river bridge is easy either. All three, however, can expect a life to first maintenance of 50 years or more. This fully justifies the decision to select galvanising, because almost any other protection system would have needed full maintenance by now. In the future, bridge owners will undoubtedly be influenced by whole life costs when they decide which material and which protection system to select. Galvanised steel can significantly reduce whole life costs, particularly in this smaller bridge market where pre-cast concrete presently has high market share. Bridges using galvanising as the sole means of corrosion protection will allow steel construction to challenge historical views in this area. Bridge engineers use steel because it is quick to build, light and strong. However, it also needs corrosion protection. This paper shows that galvanising can give steel bridges a very long, maintenance-free life. (VDEh)