Probabilistic lifetime assessment of RC structures under coupled corrosion–fatigue deterioration processes

Structural deterioration is becoming a major problem when considering long-term performance of infrastructures. The actions of corrosive environment, cyclic loading and concrete cracking lead to structural degradation. The interaction between these conditions can only be taken into account when modeling the coupled phenomena. In this paper is proposed a new model to assess the lifetime of RC structures subject to corrosion–fatigue deterioration processes. Separately, corrosion leads to cross-section reduction while fatigue induces the nucleation and the propagation of cracks in steel bars. When considered together, pitting corrosion nucleates the crack while environmental factors affect the kinematics of crack propagation. The model is applied to the reliability analysis of bridge girders located in various chloride-contaminated environments. Overall results show that the coupled effect of corrosion–fatigue on RC structures strongly affects its performance, leading to large reduction in the expected lifetime.