Reliability-based Allowances of Corrosion Losses for Weathering Steel Bridges

Abstract

Low demands on maintenance and 100% recyclability cause the growing popularity of weathering steel bridges worldwide. Recent experimental results made it possible to derive generic probabilistic models describing long-term corrosion losses for various types of weathering steels and exposures. In the contribution, these probabilistic models are applied in reliability assessment. For representative structural members and failure modes, the material allowances for the loss of thickness are derived to achieve a specified target reliability in exposures corresponding to Corrosivity Categories C2 and C3. Numerical analysis reveals that the allowances recommended by the ECCS guideline are generally conservative. For larger sections exposed in C2, a “no allowance” strategy might even be considered. For C3, design allowance of about 0.5-0.6 mm is then determined by the probabilistic approach.