Purpose This paper will study the flexural performance of multi-beam steel-hybrid fiber-reinforced concrete (HFRC) composite box beams, exploring the differences in the flexural performance of this type of composite beam under various shear connection forms and different types of loading conditions. Design/methodology/approach Flexural loading tests were conducted on two multi-beam composite beams, one with stud connectors and the other with Perfobond Leiste (PBL) connectors, under various types of loading conditions. Through comparative analysis of the failure modes, load-bearing capacity, ductility, shear lag effects, cross-sectional and rebar stresses, as well as relative slips of composite beams, the flexural performance of this type of composite beam was ultimately evaluated. Findings Under flexural loading, both specimens ultimately exhibited typical flexural failure characteristics and were consistent with the assumption of plane section. The composite beam specimens with stud connectors exhibited slightly higher flexural bearing capacity and average ultimate deflection of each main beam compared to those with PBL connectors, with increases of 1.13 and 10.05% in bearing capacity and deflection, respectively. Meanwhile, the composite beam specimens with stud connectors exhibit relatively better ductility, with displacement ductility coefficients of 3.63 and 3.36 for the two specimens, respectively. There were differences in both the magnitude of relative interface slip and the location where maximum slip occurred between the two specimens, with the maximum slip occurring at the support cross-section and L/4 cross-section, respectively. Furthermore, the differences in the influence of various types of loading conditions on the flexural performance of composite beams were determined through a comparative analysis method. Originality/value In this paper, HFRC is applied to composite beam structures, realizing a combination of high-performance materials and structures. Meanwhile, this study also considered different shear connection forms, the structural forms of bridges during actual service and operation and the stress states under various types of loading conditions. The corresponding conclusions derived from the analysis conducted in this study can provide certain reference for the design and application of practical engineering projects in the future.
Xu et al. (Tue,) studied this question.