Analysis of condition evaluation and structural safety for rebar exposure and corrosion in RC slab bridge decks

초록

This study examined condition evaluation and structural safety owing to rebar exposure and corrosion at the bottom of RC slab bridges, which accounts for 23.5 % in the domestic bridges and 55.2 % among the aged bridges. A numerical model of an RC slab bridge was constructed using the design drawings of an actual bridge. A total of 35 scenarios for rebar exposure and corrosion rates were defined according to the condition evaluation procedure and criteria specified by the Korea infrastructure safety corporation. Cover concrete at the position where rebar is exposed and corroded was assumed to be completely removed. The results of the study showed that the safety factor and load-carrying capacity of the RC slab bridge were rarely affected by the exposure rate but they tended to decrease linearly with increasing corrosion rate. According to a linear trend analysis, the safety grade was evaluated as A up to approximately 4 % of rebar corrosion rate, C up to 10.77 %, D up to 16.74 %, and E for more than 16.74 %. As the number of aging bridges increases, a comparative study will be required to investigate the condition evaluation by visual inspection and the safety evaluation due to rebar corrosion. © 2021 by Korea Concrete Institute.

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