To investigate the bond behavior and constitutive relationship at the interface between steel bars and recycled concrete

15 beam-type specimens were designed to test the bond-slip behavior of reinforced recycled concrete. The design parameters included recycled coarse aggregate substitution

recycled fine aggregate substitution

steel bar shape

steel bar diameter and anchorage length. The influence of the above variables on the load-slip curves

bond strength and bond efficiency coefficient between steel bars and recycled concrete was analyzed synthetically

and the bond-slip constitutive relationship was proposed. The results show that: with the increase of recycled coarse aggregate replacement ratio

the bond strength between steel bars and concrete decreases; however

the anti-slid ability increases. The recycled fine aggregate addition makes the bond behavior become weaker significantly. The bond strength between deformed bars and recycled concrete is about 2 times of that between plain bars and recycled concrete. The interfacial bond behavior of reinforced recycled concrete becomes poorer with the increase of steel bar diameter and anchorage length. The proposed bond-slip constitutive relationship and parameters of reinforced recycled concrete fit the experimental results well.