Effect of exposure conditions on the chloride concentration profiles in a marine concrete structure, studied by means of the kernel density estimation technique and a Gaussian–Lorentzian model

Abstract

The corrosion of the embedded steel due to chloride action is one of the main degradation problems limiting the service life of reinforced concrete structures in a marine environment. Modelling chloride profiles into concrete is a key factor to predict durability of structures. Experimental profiles from the harbour of a Mediterranean city are here studied fitting them to a Gaussian–Lorentzian peak model. This model is suited for the observed peak-shaped profiles, yielding descriptive transport parameters for both the convective and the diffusive zones. The parameters of the diffusive zone are found to be in agreement with the solution of the Fick’s second law of diffusion. The obtained parameters describing the profiles are statistically analysed by means of the kernel density estimation technique in order to determine how exposure conditions affect these parameters. A criterion of probability density distributions overlapping is used to draw conclusions about how exposure time, orientation respect to sea, wind, and splash affect the height and location of the chloride peak concentration, and the transport coefficients in the convective and diffusive zones of the profiles.