Chen Xudong, Ma Qinyong
School of Civil Engineering and Architecture, Anhui University of Science and Technology, Huainan, 232001, Anhui, China.
School of Civil Engineering, Anhui Jianzhu University, Hefei, 230601, Anhui, China.
Sci Rep. 2024 Sep 6;14(1):20784. doi: 10.1038/s41598-024-71880-8.
The performance of joint connections in composite slabs is crucial for ensuring their bidirectional load-bearing capacity and overall structural integrity. To effectively address the challenge of protruding rebar in precast components, a new structural form of a tightly connected hollow concrete composite slab without protruding rebar on the slab side is proposed. To investigate the mechanical performance and failure modes of this slab-side tight-joint connected hollow concrete composite slab, bending performance tests under monotonic load were conducted on three tightly connected hollow composite slabs and one seamless hollow composite slab. The analysis focused on the failure modes, crack distribution, bending capacity, and bending stiffness of additional steel bars at the joints of the slabs. The results indicate that, under normal operating conditions, the flexural performance development of concrete hollow composite slabs with tightly connected slab sides is generally consistent with that of the non-spliced cast hollow composite slab. Under ultimate conditions, tearing or brittle fracture failure at the joint interface is likely to occur in the composite slabs, leading to a reduction in flexural bearing capacity. With an increase in joints, the bending capacity of the hollow composite slab decreases by 17.1%, Conversely, when joints are positioned away from the most stressed section, the flexural stiffness of the section increases by 13.5%. A comparison of experimental data and theoretical calculations indicates that the additional rebar at the joints effectively contributes to the lateral load transfer in the hollow composite slab, achieving bidirectional load-bearing capacity. This further validates that the design of the single-joint, tight-joint connected hollow concrete composite slab without protruding rebar meets the requirements for bidirectional load-bearing performance.
组合板中节点连接的性能对于确保其双向承载能力和整体结构完整性至关重要。为有效应对预制构件中钢筋外凸的挑战，提出了一种新型结构形式的紧密连接空心混凝土组合板，该板在板侧无钢筋外凸。为研究这种板侧紧密连接空心混凝土组合板的力学性能和破坏模式，对三块紧密连接空心组合板和一块无缝空心组合板进行了单调荷载作用下的抗弯性能试验。分析重点在于板节点处附加钢筋的破坏模式、裂缝分布、抗弯承载力和抗弯刚度。结果表明，在正常使用条件下，板侧紧密连接的混凝土空心组合板的抗弯性能发展与非拼接现浇空心组合板基本一致。在极限条件下，组合板在节点界面处可能发生撕裂或脆性断裂破坏，导致抗弯承载力降低。随着节点数量增加，空心组合板的抗弯承载力降低17.1%，相反，当节点远离应力最大截面时，该截面的抗弯刚度增加13.5%。试验数据与理论计算的对比表明，节点处的附加钢筋有效地促进了空心组合板中的横向荷载传递，实现了双向承载能力。这进一步验证了无钢筋外凸的单节点、紧密连接空心混凝土组合板的设计满足双向承载性能要求。
