Based on the reversed cyclic loading tests of 21 nearly full-size interior joints in completed reinforced concrete frames,the law of bond deterioration of beam bars crossing the joint is tested and analyzed,which is influenced by the axial load ratio,shear-compression ratio,reinforced bar strength,concrete strength and the relative length of beam bars crossing the joint.By the nonlinear fitting method,the formula of the bond stress τ between steel crossing interior joints and concrete under different loading step is obtained.According to the loading approach,the propositional formula of the relative length of beam bars crossing the joint hc/d is presented,which is influenced by axial load ratio,shear-compression ratio,reinforced bar strength and concrete strength.

The bond stress between steel and concrete in earthquake-resistant frames is influenced by axial load ratio, shear-compression ratio, reinforced bar strength, concrete strength, and relative length of beam bars crossing the joint.

Experimental Research on Beam Bar Bond Deterioration of the Interior Joint in Earthquake-resistant Frames

Key Takeaway: The bond stress between steel and concrete in earthquake-resistant frames is influenced by axial load ratio, shear-compression ratio, reinforced bar strength, concrete strength, and relative length of beam bars crossing the joint.