Improved non-uniform aging model considering spatial variability and corrosion tendency for aging bridge

초록

This study presents an improved non-uniform aging model for reinforced concrete (RC) bridges that considers the spatial variability and corrosion tendency under varying exposure conditions. Aging is caused in bridge columns by their various exposure conditions and corrosion types, resulting in non-uniform corrosion along the column height. Current aging models assume uniform corrosion or rely on randomness for non-uniform corrosion, thereby failing to capture the spatial variability of corrosion. To overcome these limitations, a non-uniform aging model was simulated by incorporating the random field theory. The random field was modeled as a multi-variate non-stationary random field formulation to consider the inhomogeneous spatial variability and multiple crosscorrelations between variables for corrosion. As a case study, the proposed non-uniform aging model was implemented on popular RC bridge type in Korea, and the seismic performances of individual columns and bridge systems were analyzed according to the exposure conditions and times. The cases of applying an existing aging model that neglects non-uniformity or spatial variability were also analyzed and the results were compared to verify the effectiveness of the proposed aging model. The results showed that the proposed aging model successfully represents spatial variability and captures localized corrosion concentrations related to bridge performance degradation.

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