Steel-concrete bond deterioration due to corrosion: finite-element analysis for different confinement levels

The effect of corrosion on bond strength of ribbed bars in reinforced concrete (RC) is studied by axisymmetric finite-element analysis, modelling different levels of confinement given by the transverse steel reinforcement. The importance of this parameter is highlighted by a summary of the experimental results in the literature. An approach is developed to model the corrosion product expansion causing concrete-cover cracking. The numerical analyses reproduce the experimental results of the bond tests performed in two different studies. A parametric study shows the effect of the varying transverse steel percentage on the residual bond strength, and the influence of different arrangements of confinement bars. These results lead to a discussion of the different findings of several experimental researches. The conclusions regard the main parameters to be included in a model to predict the bond strength of corroded bars. Some indications for the assessment of corroding structures are given.