Flexural behavior of shallow cellular composite floor beams with innovative shear connections

• Extensive program of flexural tests on shallow cellular composite floor beams with innovative shear connections.
• Flexural behavior and failure mechanisms of shallow cellular composite floor beams.
• The forces transfer mechanism in shallow cellular composite beam is defined.
• The mechanisms of failure of the “perfobond-like” shear connection have been identified.
• A simple procedure is presented to determine the shear resistance of shear connections and the bearing capacity of the beam.

This paper presents an experimental study of the flexural behavior and shear transfer mechanisms of shallow cellular composite beams where the concrete passing through the steel web opening is combined with a steel tie-bar element to form the shear connection. Four full-scale flexural tests were undertaken aiming to provide information on their flexural behaviors, and to assess the shear resisting properties and the failure mechanisms of the proposed shear connections. The tested composite beams showed satisfactory composite behavior and satisfactory horizontal shear resistance. It is demonstrated that combining the tie-bar with the concrete significantly increases the shear resistance, slip capacity and ductility of the shear connections. Based on the test findings, design procedures of shallow cellular floor beams which are in accordance with the stress method presented in EC4 and BS5950-3.1 and of the shear connection were developed. The design procedures were verified against the test results and were found to be consistent.