Bond capacity between H‐shaped steel and recycled concrete under cyclic loading

SummaryThe premature debonding at the H‐shaped steel‐recycled concrete interface is the main cause of performance degradation for steel reinforced recycled concrete (SRRC) structures especially subjected cyclic loading. However, the bond behavior and shear transfer mechanism under cyclic loading has not been fully understood. For this reason, totally 14 SRRC specimens were performed under cyclic loading. The effects of replacement ratio of recycled concrete (r), thickness of steel concrete cover (Css), reinforcement ratio (ρsv), and recycled concrete strength (fc) are studied. Besides, the bond‐slip constitutive model considering the position function of steel was investigated. The results indicated that the bond capacity of specimen gradually degenerates under cyclic loading, and the load‐slip curves show an obvious “pinching” phenomenon. The bond failure process can be divided into four stages: micro slip stage (O–A), slip development stage (A–B), slip rapid increase stage (B–C), and residual stage (C–D). The average ultimate bond strength of specimen under cyclic load is about 60% of that under pull‐out load. Based on the analysis, bond‐slip constitutive model between H‐shaped steel and recycled concrete was proposed.