Mechanical performance and bond-slip model of adhesively bonded joints between Fe-SMA and concrete

The vast scale of reinforced concrete structures in civil engineering, combined with their ongoing aging and damage, has led engineers and researchers to propose numerous reinforcement and repair solutions. In recent years, iron-based shape memory alloy (Fe-SMA), as a low-cost, self-prestressing intelligent material, has been demonstrated as a competitive alternative to traditional reinforcement materials such as steel and carbon fiber reinforced polymer (CFRP), exhibiting significant potential in structural strengthening applications. When using Fe-SMA to reinforce concrete structures, it is crucial to ensure a reliable connection between the two materials for effective load transfer, but research in this area, both experimental and theoretical, remains limited. To investigate the load transfer mechanism and failure criteria of Fe-SMA/concrete adhesively bonded joints (BoJs) under shear forces, shear tests are conducted on 20 sets of bonded joint specimens composed of Fe-SMA plates (FSPs) and concrete blocks. The effects of adhesive layer thickness (ALT), bond length (BL), and structural adhesive type on the mechanical performance of these joints are analyzed. Besides, this study proposes the bond-slip model of bonded joints between Fe-SMA and concrete in structural reinforcements, laying a experimental and theoretical foundation for promoting the reinforcement utilization of Fe-SMA in civil engineering, especially for concrete structures.