Numerical modeling for predicting service life of reinforced concrete structures exposed to chloride environments

Degradation of reinforced concrete (RC) structures due to chloride penetration followed by reinforcement corrosion has been a serious problem in civil engineering for many years. In the present paper, a systematic and robust model for predicting service life of RC structures is developed which takes environmental humidity and temperature fluctuations, chloride binding, diffusion and convection, as well as the decay of structural performance into account. The interactions between the decay of structural performance, heat and moisture transfer are considered in a coupled thermal-hygro-mechanical model. The governing equations of heat, moisture and chloride transport into nonsaturated concrete are described particularly and solved numerically by finite element analysis in space and time domains. Comparisons of numerical results with analytical solutions and experimental observations are conducted to establish the validity of the proposed numerical model. Applications of the numerical model are demonstrated by predicting service life of a RC slab exposed to a chloride environment.