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Title |
Analysis of structural safety for rebar exposure and corrosion in PSC I-girder bridge slab
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Authors |
한만석(Manseok Han) ; 박주현(Ju-Hyun Park) ; 이종한(Jong-Han Lee) ; 민지영(Jiyoung Min) |
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DOI |
https://doi.org/10.11112/jksmi.2021.25.1.67 |
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Keywords |
PSC I형 교량; 바닥판; 철근노출면적률; 철근부식률; 안전율; 내하율; 안전성평가 PSC I-girder bridge; deck; rebar exposure rate; rebar corrosion rate; safety factor; rating factor; safety evaluation |
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Abstract |
This paper evaluated the structural safety of an aging PSC I-girder bridge with rebar corrosion in the deck. The geometry and rebar of the bridge were designed based on an actual PSC I-girder bridge, and the numerical analysis was performed considering the crack of concrete and yielding of steel rebar. According to the evaluation criteria of Korea Infrastructure Safety and Technology Corporation, this study defined two criteria of rebar exposure and corrosion rates to construct a total of 32 corrosion scenarios. Rebar exposure was defined as the exposure of tensile rebars in the bridge deck due to the removal of cover concrete. The results of the analysis showed that the safety and rating factors of the bridge decreased with increasing rebar exposure and corrosion rates. For the rebar corrosion rate more than 50%, the safety grade of the bridge should be carefully evaluated for all the rebar exposure rate. When the rebar corrosion rate exceeds 57%, the bridge was evaluated as E grade regardless of rebar exposure rate. A correlation analysis for a 2% of rebar exposure rate found that the bridge was evaluated as A grade up to 55.8% corrosion rate, C grade up to 56.9%, D grade up to 58.5%, and E grade for corrosion rate greater than 58.5%. This study indicates the necessity of a quantitative evaluation of rebar corrosion for evaluating the structural safety of aging bridges.
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