Experimental study on bond-slip behavior of vertical connecting rebar in the horizontal joints of double- superimposed shear wall

The horizontal joint of double-superimposed shear wall is the important part affecting the seismic performance of the wall. The horizontal joint mainly relies on the synergistic action between the vertical connecting rebar and the cast-in-place concrete to transfer the horizontal and vertical loadings and coordinate the deformation. Therefore, it is necessary to study the bond-slip behavior between the vertical connecting rebar and the cast-in-place concrete. In this paper, the effects of the cast-in-place layer thickness, the concrete strength, the anchorage length, and the diameter of rebar on the interface bond properties of vertical connecting rebar were analyzed through pullout tests. Based on the experimental results, the calculation formulas for bond strength and peak slip were proposed. According to the distribution of bond stress along the anchorage length, the bond-slip constitutive model optimized by the bond position function was established to describe the bond-slip behavior between the vertical connecting rebar and the cast-in-place concrete.