Numerical Solutions for Chloride Diffusion Fluctuation in RC Elements from Corrosion Probability Assessments

Mechanical diffusion of chloride ions in reinforced concrete (RC) structures varies in time and space, and depends on uncertain factors such as material properties, temperature, humidity, and aging. In this paper, different scenarios considering the time of corrosion initiation and the influence of the chloride diffusion coefficient for different loadings (i.e., constant, sinusoidal, Gaussian, and random) were proposed. Stochastic analyses were carried out to estimate the probability of failure of steel bars, and to evaluate the influences of the internal and external factors. Advanced numerical solutions were developed to account for these influences under non-constant diffusion coefficient and non-steady-state condition. Results show that the chloride content can assume low values by using the oscillations of the generic function (e.g., sinusoidal and general) instead of constant function. The influence of the temperature appears relevant. The 3D analyses, considering the random variability, show that chloride content can be higher than similar to 1.50 compared to chloride content using traditional approaches. Stochastic approaches plus advanced solutions allow, in a more complete way, the sustainability decision-making process during the design phase, maintenance, inspections, and repair.

Automated summary

This study proposes different scenarios for the influence of corrosion initiation time and chloride diffusion coefficient on loadings, and conducts stochastic analyses and numerical simulations. The results show that temperature and oscillations of functions have significant impacts on chloride diffusion, and the analyses considering random variability yield higher chloride content compared to traditional approaches.