Numerical modelling of corroded RC columns repaired with high performance fiber reinforced concrete jacket

Reinforcement corrosion can lead to a severe damage in reinforced concrete columns with subsequent loss of bearing capacity. This condition can be deleterious in case of a seismic event. The possibility of repairing and strengthening damaged columns with high performance fiber reinforced concrete (HPFRC) jacketing has been experimentally investigated by some of the authors in previous papers, through full-scale tests on specimens under cyclic loads. The main aim of the intervention was not only to restore the original bearing capacity but also to increase the column durability. In the present paper, a numerical model is developed with the FEM software Diana in order to simulate the cyclic behaviour of corroded r.c. columns reinforced with HPFRC. Particular attention is devoted to the simulation of the corrosion phenomenon and to the strain localization due to the jacket presence. The chemical attack is defined in such a way to account for both the geometrical and mechanical variations of the bar properties. The numerical analyses represent a very useful tool for highlighting the main parameters that have to be considered in evaluating the behaviour of the damaged and then repaired elements. Finally, they constitute a support for the design and, as a consequence, for the reinforcement optimization.