Relation between corrosion level and composition of accumulating salt on the weathering steel bridges

To discuss the relation of accumulating salt and corrosion state on weathering steel bridges, we investigated chemistry of salt and corrosion state on the bridges in southwestern Japan. Quantities of Na + and Cl - on girders are positively correlated with rust thickness and corrosion rank, indicating that the accumulating ions enhance the corrosion. Relative to web, lower flange is enriched in Na + and Cl - , and shows worse corrosion feature. The enrichment of ions on lower flange probably results from migration of accumulating salt from web to lower flange due to rain and dew.