Corrosion Acceleration Test on Weathering Steel and Paint-coated Steel for Bridge Structural Members

A new accelerated corrosion test authorized as ISO16539 Method B in 2013 has shown a good correlation with corrosion behavior in an actual corrosive atmospheric environment. This study aims to extend the application of this method to steel bridge members. The corrosion acceleration tests by the ISO 16539 Method B to weathering steel without anti-corrosive coating and paint-coated steel were conducted through 6 months of the test periods. A series of fundamental studies were conducted to clarify the characteristics of this test in the durability evaluation of the steel used for bridge structural members by comparing the results of the atmospheric exposure test. The accelerated test of 168 days produced the thickness reduction by 10 to 14 times larger than the exposure test of 365 days to the weathering steel. The blister area of the paint-coating as a measure of the paint degradation by the accelerated test was 11 to 14 times larger than the exposure test of 365 days to paint-coated steel. These results showed the effectiveness of the accelerated test by ISO16539 Method B to evaluate the degradation characteristics of the weathering steel and the paint-coated steel.