Use of quality indices in comparison of corroded technical steel bars B500c and S500s on their mechanical performance basis

The nominal cross-sectional area-based quality index QD has been utilized to evaluate and compare the mechanical performance of steel grades B500c and S500s. Although when uncorroded B500c has better mechanical performance than S500s, after 60 days of accelerated corrosion exposure, quality index values of B500c drop significantly below the respectives of S500s. Responsible for this behavior is localized corrosion damage detected in B500c steel bars only. The constant improvement of the mechanical properties of concrete reinforcing steel bars by neglecting the long time effect of corrosion may lead to unexpected results in the long run. A revision of the standards such as to account for corrosion effects on the material properties seems to be imperative.