Investigation on Residual Cyclic Strength Capacity of Corroded Steel Bridge Members

Steel bridges play a major role in road and railway infrastructures hence it directly influence on economy of any country. Traffic capacity reduction or even a temporary closure generates major inconveniences for the users and result in significant losses to the economy. Corrosion is one of the most significant causes of age related deterioration of steel girder bridges which affects their strength, long term mechanical performance, usability and durability. Numerous steel bridge structure collapses are associated with dynamic loadings like earthquakes and wind loading. Damaging vulnerability of steel structures due to dynamic excitations can be triggered with corrosion. Non availability of information and convenient methodology to determine the behavior of corroded steel members can lead to problematic situations for the civil engineers when evaluating the strength of deteriorated member. Therefore a comprehensive study in front of serviceability and ultimate limit states is necessary to develop efficient techniques to evaluate the structural integrity and safety. This is necessary to evaluate the feasibility of those steel structures for the current usage and to figure out the retrofitting requirement of corroded members. This research proposes a simple and reliable methodology to estimate remaining yield and ultimate cyclic strength capacities by measuring only the minimum thickness of a corroded surface based on the results of many experimental coupon tests and results of nonlinear FEM analysis of many actual corroded plates with different corrosion conditions, which can be used to make rational decisions about the maintenance management plan of steel infrastructures