AISC
Durability of Steel Bridge Corrosion Protection Systems Using Environment-Based Accelerated Corrosion Testing
- Primary Investigator(s): PI: Jennifer McConnell | Co-PI: Clara Chan | Research Assistants: Julie Giannino and Nate Young | Other Contributors: Sally Saleem and Tian Bai
- Institution: University of Delaware
- Year Completed: 2021
Final Research Report
Abstract
The purpose of this study was to evaluate the performance of five of the most common corrosion protection systems used in steel bridges: uncoated weathering steel (UWS), galvanizing, metallizing, 1-coat inorganic zinc paint, and a 3-coat organic zinc paint system, in relatively corrosive environments. The premise of this scope was that UWS is the preferred material type in most environments; but in relatively severe environments, alternative corrosion protection systems may provide benefits in terms of both corrosion protection and life cycle cost. The severely corrosive environments considered in this research are coastal environments where natural chlorides are present and environments where chlorides are present via the high use of deicing salts.
Performance was evaluated first through a statistical analysis of existing field data (Chapter 2 of the Report) and subsequently through the implementation of laboratory accelerated corrosion testing. The laboratory accelerated corrosion testing was customized to the goals of this research by benchmarking the laboratory results to prior field work of UWS bridges in severe environments (Chapter 3 of the Report). This methodology was applied to each of the five corrosion protection systems for 80 cycles, representing 80 years in the field (Chapter 4 of the Report). The results of this work were used to provide longevity estimates for each of the corrosion protection systems based on various performance benchmarks described in Table 4-2 of the Report. The implications of the longevity estimates show that steel can provide a long service life even in a relatively severe environment. Use of any of these corrosion protection systems can improve performance, increase service life, decrease required maintenance, and provide economical steel bridges. A more detailed summary of this work, key conclusions, and suggestions for future work are presented in Chapter 5 of the Report.
2022 World Steel Bridge Symposium Presentation on the Project
This research project was presented at the 2022 World Steel Bridge Symposium in Denver, Colorado. The video recording of this presentation can be viewed below.