Behavior of composite beams with cold-formed steel joists and concrete slab

Abstract

A new composite beam and floor system has been developed herein to achieve a stronger strength and ductility, as well as to yield a more economical design purpose. This new composite beam system consists of three elements: reinforced concrete slab on corrugated cold-formed metal, back to back cold-formed steel joists, and cold-formed furring shear connector. The shear connectors are screwed through the top flange of the support joists in order to provide vertical interlocking and horizontal shear resistant between the concrete slab and the cold-formed steel joists. The self-drill fasteners are used for fastening the furring shear connector through the metal deck into supporting joists. To understand the behavior of the new composite beam, a total of six large-scale bending tests were conducted to obtain the positive moment capacity, vertical deflection, and end slip of proposed composite beam system. Comparing with the non-composite section, the proposed composite section presents a better performance for both strength and ductility. The present experimental test results are also compared with the proposed analysis and design method which is not currently available in the AISC or AISI specifications.