THE PUNCHING STRENGTH OF UNBONDED POST-TENSIONED SLABS AT COLUMNS

The results of eight tests on post-tensioned unbonded flat slabs involving both shear and moment transfer at columns are presented. The amount of moment transferred to the columns is compared with predictions based on frame analysis and finite element analysis. A comparison is also made of the shear capacity with that predicted by the British and American codes and an improved method is proposed. The proposed method was found to give more consistent results than those found using either of the current recommendations.