Investigation on the bonding behavior between corroded rebars and recycled brick‐concrete aggregate concrete

Abstract The rational utilization of recycled brick‐concrete aggregate concrete (RBAC) can effectively reduce the resource and environmental issues caused by construction waste. The synergistic use of recycled brick aggregate (RBA) and recycled concrete aggregate (RCA) enables more effective application of green building materials while reducing carbon emissions during construction production. When used in structural applications, the durability of RBAC remains a key concern. This study focuses on the interfacial degradation performance between RBAC and corroded steel bars, aiming to analyze the influence patterns of the substitution ratio of RBA, the degree of steel bar corrosion, concrete strength, rebar diameter, embedded length, stirrups spacing, cover thickness, and steel bar shape on the bonding behavior of RBAC specimens, and to reveal the degradation mechanism of steel bar corrosion on RBAC specimens. Through experiments, theoretical analysis, and finite element simulation, the bond strength, slip characteristics, and interface deterioration performance of RBAC specimens under different conditions were investigated. The results indicate that the bond strength of RBAC specimens significantly decreases when the degree of corrosion reaches 10%, and the optimal substitution ratio of RBA is 50%. Increasing the anchorage length, cover thickness, and reducing stirrup spacing can reduce the slip at structural failure. The stirrup spacing has a notable impact on the interfacial confinement performance. Finally, calculation formulas for the bond strength and residual bond strength of RBAC specimens considering the synergistic effects of multiple factors were established. A segmented bond‐slip constitutive model was optimized, and its reliability was validated through finite element simulation. This research can contribute to accurately assessing the safety and durability of RBAC structures in practical engineering, providing a scientific basis for engineering design and construction.