PREDICTION OF SHEAR RESISTANCE FACTOR IN FLAT SLABS DESIGN USING CRITICAL PERIMETER OF SUPPORTING COLUMNS

The distribution of shear stresses at the slab–column connection of flat slabs become non–uniform in the presence of unbalanced moment. The shear resistance (β) factor is used to account for this distribution of shear stresses due to the transfer of unbalanced moment at the slab–column connections. The provisions of the American, Canadian, European and Model codes, regarding the transfer of unbalanced moment at slab–column connections of flat slabs are compared. The relationship of β-factor to the ratio of critical perimeter to the control perimeter of an internal column have been plotted as a simplified approach and additional approximate factors have been found for an internal corner column and various locations of cantilevered edge, corner and internal corner columns encountered in practice by engineers. These additional approximate factors have been proposed for inclusion in European code for situations where adjacent spans do not differ by more than 25%.http://dx.doi.org/10.4314/njt.v36i1.