Probabilistic evaluation of deflections and natural frequencies of RC beams subject to corrosion

In the paper the effect of corrosion on deflections of RC beams and, subsequently, on the probability of serviceability failure due to excessive deflection is considered. A nonlinear finite element model is used to describe the structural behaviour of RC beams with corroded reinforcement. Since it has been noted that the deterioration of bond between corroded reinforcement and concrete may have a significant influence on the RC beam deflections, special attention is paid to modelling this phenomenon. The proposed finite element model is validated against available experimental data with a good agreement observed. Other parameters of RC beams, which may be influenced by reinforcement corrosion, are the beam natural frequencies, whose changes also reflect the effect of corrosion on the beam stiffness. In the paper, the dependence of the first three natural frequencies on the level of reinforcement corrosion is examined. Results of the analysis provide information on the influence of corrosion on the beam stiffness
and also give an indication of the possibility to use changes in the natural frequencies for identification of
corrosion-induced damage in RC beams. Uncertainties associated with the model and available data are
taken into account. Results show that an increase in deflections due to corrosion has a lesser effect on
serviceability of RC beams than corrosion-induced cracking.