More than 9% of the bridges in the United States were labeled structurally deficient according to the 2017 American Society of Civil Engineers’ infrastructure report card. Aging infrastructure has caught more and more attentions recently in the United States. The main causes of bridge deterioration are repeated vehicular loads and adverse environmental exposure. The most dominant deterioration form for steel bridges is corrosion, which is due to moisture exposure, leakage through deck joints as well as the frequent use of deicing chemicals during the winter season in cold regions. At times, the rust is serious enough to disconnect the web from the flanges of the girder. Excessive rust accumulation and metal area loss pose significant concerns for structural capacity reduction especially at girder ends. The consequences of bridge failure can be disastrous. In this study, the residual strength of corroded steel girders is evaluated by 3-D finite element modeling and laboratory testing. Our analysis and testing are focused on the effects of web area loss and web thinning on shear and web buckling capacity reduction. The finite element models built in ABAQUS resemble the real steel corrosion forms by varying the shapes, sizes and locations of the area loss. Tests on the scaled steel beam specimens are conducted to verify the numerical modeling results. In laboratory testing, corrosion forms of the steel beam specimens are controlled by soaking the beams into bleach solution for a sustained period to develop the desired amount of rust and/or by cutting holes of various sizes and shapes on the beam webs. Compression tests on these corroded specimens are conducted using the Material Testing System. The residual strengths of the steel beam specimens with different corrosion conditions are analyzed and compared with the 3-D finite element modeling results. Based on our analyses and findings, a simple and dependable strength evaluation method for corroded steel girder bridges is proposed.
Date of creation, presentation, or exhibit
Department, Program, or Center
Civil Engineering Technology Environmental Management and Safety (CET)
Bao, Amanda, "Structural Capacity Analysis of Corroded Steel Girder Bridges" (2019). Accessed from
RIT – Main Campus
Slides for presentation at the 2019 World Steel Bridge Symposium