Durability of concrete bridges in marine environment in Norway

There are about 277 concrete bridges with total length 30m or more along the coast of Norway. Approximately 80 % of these bridges are situated along the coastline, from Hordaland in the south to Finnmark up north, hence being exposed to rather rough weather conditions. Investigations based on 149 of the bridges mentioned above, in some cases show a distinct relationship between the predominant winddirection (regarded as an important parameter) and chloride penetration on the structures being considered. Measurements show the lowest chloride content on that side of columns facing wind and rain. 25 % of the bridges had a high chloride content with rebar corrosion and concrete spalling. The diffusion coefficient (D in m 2 /s) for chloride penetration calculated with use of laboratory testmethods are 5-30 times higher than the diffusion coefficient calculated from the chloride penetration profiles which was measured on concrete that had been exposed to actual seawater splashing.