Section loss in naturally corroded 7-wire steel strands in external tendons

Abstract

Naturally corroded seven-wire strands obtained from two in-service bridges were examined. All strand samples were cut into cross sections, and the corrosion depths and corroded areas were measured. Among various corrosion mechanisms, a majority of samples investigated were categorized as general corrosion. The trends in the section losses in the strands with respect to average corrosion depth were similar and showed a clear linearity. The average corrosion depth measured from the outside of strands showed an overall linear trend with section loss when the inside of strand cross-sections could not be observed and measured. In this study, a method to estimate section loss for general corrosion of a 7-wire strand is developed by using corrosion depth in the visible region. Although a limited number of samples were obtained from only two bridges, the section loss estimates were comparable to actual measurements. The study of strand samples corroded during service offers a rare opportunity and should distinguish this study from previous ones.

Keywords:

• Cables and tendons
• concrete structures
• corrosion
• damage assessment
• deterioration
• maintenance and inspection
• measurement
• tensile members

Acknowledgements

The authors would like to acknowledge the contribution of Prof. Chang-Su Shim and Chi-Ho Jeon for sharing their valuable strand samples.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This research was inspired by the R&D project supported by the Seoul Metropolitan Facilities Management Corporation. Partial support was received from a grant (19SCIP-B128568-03) from the Smart Civil Infrastructure Research Program funded by the Ministry of Land, Infrastructure and Transportation of the Korean government via the Institute of Construction and Environmental Engineering at Seoul National University.