Variation and degradation of steel and concrete bond performance with corroded stirrups

Stirrups are more vulnerable than rebar to environmental corrosion in real reinforced concrete structures. Corrosion of stirrups would degrade the confinement and may damage bond between rebar and concrete. This paper studied effects of stirrups corrosion on bond behaviors. 60 specimens were manufactured and divided into 5 groups with stirrup corrosion levels in the targeted range of 0-20%. Monotonic pull-out and cyclic loading scenarios were carried out to get the parameters of bond behaviors. The test results showed the degradation of bond parameters are less severe compared to that of rebar corrosion. It was also found that coefficient of variation of bond strength and corresponding slip value increased significantly for corroded members compared to that of intact members.