doi:10.3850/978-981-08-7619-7_P050

ABSTRACT

Steel corrosion of reinforced concrete structures subjected to chloride penetration is analyzed in this work, in a suitable probabilistic context. A complete time-dependent stochastic model is developed that can simulate all three stages of reinforced concrete corrosion, i.e. corrosion initiation, crack initiation and propagation. Chloride ion intrusion in concrete is modeled based on Fick's second law of diffusion taking into account time and temperature dependence of the apparent diffusion coefficient. The dynamic influence of propagating cracks on the diffusion coefficient and consequently on the whole corrosion mechanism has been modeled as well. For the crack propagation stage a new empirical model is proposed, based on published experimental results. It combines corrosion crack width with steel-bar cross sectional loss. The spatial variability of the parameters has been taken into account by two-dimensional Gaussian and non-Gaussian, uni-variate random field simulation, using the spectral representation method. The suggested methodology is implemented in an existing port structure in South Korea and results are presented and discussed. Finally, a global sensitivity analysis, based on Sobol' indices, follows and clarifies the effect of each input parameter on the results.

Keywords: Steel corrosion, Chlorides, Crack propagation, Random field, Sensitivity analysis, Monte Carlo simulation, Generalized Linear Model.

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