A study of exterior slab-beam-column connections in flat plate floors
Baumgartner, John L
Jirsa, James O.
Master of Science
The problem considered here concerns the transfer of load from the slab to the exterior columns of flat plate floor slabs. At the exterior columns, the load is transferred through a combination of shear, bending moment, and torsion. The distribution and magnitude of these forces and moments depend on the relative stiffness and strength of the spandrel beams. In general, the strength of the slab at the exterior edge is controlled by the limitations in the strength of the spandrel beams. In order to study the load transfer problem, a series of five 0. 3 scale reinforced concrete models, simulating the exterior column region of floor slabs, were tested to failure. The primary variables were the beam dimensions and reinforcement. The beam strength, which was primarily dependent upon the amount of lateral beam reinforcement, governed the amount of yielding in the slab and the extent of torsional cracking in the beam. In studying the behavior and strength of the sections, distributions of bending moments in the slab and torsional moments along the beam were determined and used in defining the failure criteria for the slab. This study indicated that spandrel beams can be designed with sufficient strength to develop the yield strength of the exterior slab section perpendicular to the spandrel beam.