Experiment on Punching Shear Capacity of Hollow Slab-column Connection under Unbalanced Bending Moment

Abstract

Through the punching shear test of six hollow slab-column connection specimens, the mechanic parameters of the hollow slab-column connection were collected, including the cracking load, the ultimate load, the displacement of the slab bottom and the strain data of steel and concrete under the influence of the unbalanced bending moment. Afterward the effect of the hollow ratio and the bending direction on the ultimate punching shear capacity of hollow slab-column connection was studied. The test results show that the capacity of hollow slab-column connection decreases with the increase of hollow ratio, but only within a narrow range. When the unbalanced moment is low, both the horizontal unbalanced moment and the along pipe unbalanced moment create almost the same impact on the punching connection. The punching capacity of the hollow slab-column connection under two-way unbalanced moment is lower than that under one-way unbalanced moment, but the final displacement is larger and the deformation ability is better. Finally the relationship between the unbalanced moment and the ultimate bearing capacity of hollow slab-column connection was proposed.