Experimental study on flexural behavior of modular prefabricated channel–concrete composite beams with dry connections

• Published in: Journal of Building Engineering 2023-06, Vol.68, p.106194, Article 106194
• Main Authors: Fang, Jiaopeng, Zhou, Lingyu, Zhu, Yibo, Li, Fengui, Dai, Chaohu, Zhou, Quan, Liao, Fei
• Format: Article
• Language: English
• Subjects: C-channel; Composite beam; Flexural resistance; Integrity; Prefabricated beam-slab module
• ISSN: 2352-7102; 2352-7102
• DOI: 10.1016/j.jobe.2023.106194

This work developed a new steel–concrete composite beam composed of two prefabricated beam-slab modules to achieve rapid assembly, reduce construction costs, and improve structural performance. The modules, comprising C-channels, concrete slabs, and perforated steel plate shear connectors, were connected back-to-back with high-strength bolts, thereby eliminating in-situ wet construction. Seven specimens with various slab widths, beam depths, and shear connector spacings were fabricated and tested under sagging moments to investigate the behavior of the proposed composite beams. The experimental results demonstrated that the tension induced by the high-strength bolts provided excellent cooperation between the beam-slab modules and ensured that the composite beam had a high level of integrity and offered good strength and ductility performance. The bonding between the C-channel and the concrete was robust enough to transfer longitudinal shear forces to the C-channel, allowing for complete shear interactions under service loading. The shear connectors provided efficient composite actions between the C-channel and the concrete slab, resulting in a slight difference in the mechanical properties of the composite beams with different shear connection degrees. As the slab width enlarged, the flexural strength and ductility of the beam enhanced by 8–19% and 11–21% respectively, but the integrity of the two beam-slab modules weakened. Increasing the size of the C-channel was conducive to the integrity of the two modules. The flexural strength of the beam with a large height increased by 96% compared with the specimen with a small height, while its ductility declined by 10%. Finally, this paper proposed simplified models based on Eurocode 4 to calculate the flexural resistance of the composite beams. •A new modular composite structural system with dry connections was developed.•Bending tests on the prefabricated composite beams in the system were conducted.•The integrity between the beam-slab modules was investigated.•The model for calculating the flexural capacity of the composite beams was proposed.