Effects of confinements on the bond strength between concrete and corroded steel bars

• The increase of concrete cover can prevent the degradation of bond strength.
• The stirrups can significantly improve the bond strength of corroded steel bars.
• Bond strength model considering confinements and current density is established.

The bond tests were carried out on 18 beam specimens to investigate the bond behavior between concrete and corroded steel bars, with corrosion and stirrups being the principal parameters. Through systematical analysis of the test results and extensive test data from the literature, the confinements were found to have significant influence on the bond strength. Considering the effects of concrete cover, stirrups and corrosion current density, empirical model for the degradation of bond strength was established. It is concluded that the proposed model can predict the test results with reasonable accuracy.