  Several aspects influence corrosive processes in RC structures, such as
environmental conditions, structural geometry, and mechanical properties. Since
these aspects present large randomnesses, probabilistic models allow a more
accurate description of the corrosive phenomena. On the other hand, the
definition of limit states, applied in the reliability assessment, requires a
proper mechanical model. In this context, this study proposes an accurate
methodology for the mechanical-probabilistic modelling of RC structures
subjected to reinforcements' corrosion. To this purpose, an improved damage
approach is proposed to define the limit states for the probabilistic
modelling, considering three main degradation phenomena: concrete cracking,
rebar yielding, and rebar corrosion caused either by chlorides or carbonation
process. The stochastic analysis is evaluated by the Monte Carlo simulation
method due to the computational efficiency of the LDMC. The proposed
mechanical-probabilistic methodology is implemented in a computational
framework and applied to the analysis of a simply supported RC beam, and a 2D
RC frame. Curves illustrate the probability of failure over a service life of
50 years. Moreover, the proposed model allows drawing the probability of
failure map and then identify the critical failure path for progressive
collapse analysis. Collapse path changes caused by the corrosion phenomena are
observed.
