Degree of composite action of steel beams with precast concrete hollow core slabs

Different construction challenges followed by harsh environmental conditions triggered the human intention to precast composite structures. The precast concrete hollow core (PCHC) slabs have been popular, especially for multi-story long-span composite structures. In comparison to conventional solid concrete slabs, they have the advantages of being more lightweight, fire-resistant, soundproof, and cost-effective. However, the composite action between the steel beams and PCHC slabs is neglected in the design codes. This paper aims to investigate the composite action between the PCHC slabs and steel beams through an experimental study. Two full-scale flexural tests were performed on specimens of 203 cm and 254 cm PCHC slabs connected to the steel beam via 19 mm diameter shear studs. Instrumentations and data acquisition systems recorded the failure modes and crack formations. Also, the digital image correlation (DIC) technique was applied to capture the neutral axis position during the loading process. Finally, the degree of composite action (DCA), an important parameter to describe the structural behavior of the composite beam, was calculated based on the analytical and experimental bending moments of the specimens.