Análise da difusão de Cloretos em Estruturas de Concreto Armado

Abstract

Chloride ion diffusion in reinforced concrete structures is one of the main mechanisms responsible for the initiation of reinforcement corrosion, directly affecting structural durability and service life. In this context, an accurate estimation of the chloride diffusion coefficient is essential for durability and performance assessments. This study aimed to analyze chloride transport mechanisms in concrete, identify the main factors influencing chloride penetration, and comparatively evaluate the performance of different mathematical models used to estimate the diffusion coefficient. The methodology was based on a systematic and critical literature review, adopting a theoretical and comparative approach and considering five widely used models: Chalee et al. (2009), Luciano and Miltenberger (1999), Riding et al. (2013), Caré (2003), and Oh and Jang (2004). The models were applied to an experimental database comprising more than 160 concrete mixtures, including different ages, water-to-binder ratios, mineral addition contents, and exposure conditions. Model performance was evaluated using the ratio between estimated and experimental diffusion coefficients (DM/DE), supported by statistical analyses of mean value, standard deviation, and coefficient of variation, as well as graphical interpretation of result distributions. The results revealed significant differences among the models, related to the dominant parameters adopted in each formulation, leading to distinct levels of conservatism, dispersion, and representativeness of experimental data. It is concluded that the selection of a diffusion model should consider the purpose of the analysis, data availability, and exposure conditions, being essential for reliable durability assessments and for the development of effective corrosion prevention strategies in reinforced concrete structures.