Experimental and theoretical study on mechanical properties of steel–concrete double-sided composite cantilever beams

Abstract

This study proposes a new steel–concrete composite cantilever beam. This new type of composite beam will be used for improved structural performance in building structures. Six steel–concrete, double-sided composite cantilever beams were designed and experimentally tested and theoretically analyzed to study its main mechanical properties. The differences between these six specimens include the positions, thicknesses, and material strength of the bottom concrete slab. This study investigated the influence of the bottom concrete slab on the bearing capacity, deflection, stiffness, and ductility of each composite cantilever beam. Static loading was applied to each specimen, and the mechanical behavior of each composite beam was evaluated and discussed. The test results demonstrate the presence of two peak loads in the load–displacement curve of the double-sided composite cantilever beam. However, the first peak load should be used as the engineering design basis. The results show that the bottom concrete slab of the double-sided composite cantilever beam can effectively enhance the stability of the bottom flange of the steel girder, ultimate bearing capacity of the composite beam, and the stiffness. Additionally, the cross-sectional stress model of each specimen at different stages was analyzed and compared with the test results. The slip and the experimental error should be considered for improved accuracy in the calculation of deflection for the cantilever composite beam.