Multiphysics finite element analysis and capacity assessment of reinforced concrete bridge piers exposed to chlorides

The analysis of reinforced concrete (RC) infrastructure in aggressive environments is a rather challenging task. Nonetheless, it is essential to design new structures as well as to predict the residual life of existing constructions and to plan suitable maintenance interventions. Therefore, this work illustrates the preliminary version of a comprehensive numerical framework conceived to assess the evolution in time of the capacity of RC structures exposed to chlorides, with focus on bridges. A nonlinear dynamic model is first developed by means of the finite element method in the attempt to simulate the transport of chlorides, taking into account binding capacity of concrete as well as the effects due to temperature and moisture. This model is then employed to estimate the free chloride content during the lifetime. Such a result is finally used to evaluate the corrosion current density and the pitting corrosion of the reinforcing bars in order to estimate the pier capacity.