Punching Strength of R.C. Flat Slabs with Moment Transfer

The paper presents results from an experimental and analytical study of interior columns subjected to punching in the presence of an unbalanced moment. The moment, characterized in the study by an eccentricity of the load in the column, is shown to have a significant effect in decreasing the punching strength. Punching shear reinforcement, while improving both the ultimate load and the deformability of the slab, is exhibiting a similar behavior with regard to the interaction of punching and unbalanced moment. Results from a parametric study show that, in most cases, unbalanced moments are small, and thus account for only a small decrease of the ultimate load capacity for interior columns, both in the presence of unsymmetrical loads and spans as in the case of imposed displacements.