Longitudinal shear behavior and design method of UHPC connection for prefabricated slabs in composite beams. (15th February 2023)

• Record Type: Journal Article
• Authors: Wang, Hao; Liu, Xiao-gang; Yue, Qing-rui; Wang, Ning; Zheng, Ming-zhao
• Is Part Of: Engineering structures. Volume 277(2023)
• Publication Date: 2023-02-15
• Subjects: Prefabricated composite beam -- UHPC wet connection -- Force-slip behavior -- Push-out test -- Calculated method; Structural engineering -- Periodicals; Structural analysis (Engineering) -- Periodicals; Construction, Technique de la -- Périodiques; Génie parasismique -- Périodiques; Pression du vent -- Périodiques; Earthquake engineering; Structural engineering; Wind-pressure; Periodicals; 624.105
• DOI: 10.1016/j.engstruct.2022.115386
• Languages: English
• ISSNs: 0141-0296

Abstract

Highlights: Proposing a concept of applying UHPC connection for the prefabricated NSC slabs in the composite beam. Investigating the effects of design factors on the shear-slip behavior of assembled composite beams with UHPC connection. Clarifying the failure mechanism of prefabricated composite beams with UHPC connection subjected to longitudinal load. Proposing calculation formulas and optimizing suggestions to design the prefabricated composite beam with UHPC connections. Abstract: Ultra-high-performance concrete (UHPC) has advantages in mechanical properties and bond properties, which was available to connect the precast members of prefabricated composite structures. In this paper, some kinds of wet connections with post-cast UHPC applied in the composite beam with prefabricated components (slab and steel beam) were designed, and the longitudinal force-slip behaviors for the above UHPC connections were investigated through a series of push-out tests. In the case of the specimens with the post-cast UHPC rectangular connection, which failed in the interface between the precast slab and UHPC connection instead of the concrete region around the stud connectors, the increase in interface reinforcement ratio was beneficial for enhancing the interface shear resistance. The arrangement of two layers of steel bars out of the precast slab side could make full use of the plastic properties of bottom interface reinforcements to strengthen the ultimate shear strength and ductility of the interface. Compared with the rectangular connection, the post-cast UHPC connection with T -section presented a better interface performance by increasing the bond area, while the increase of the transverse width only worked in a limited range due to the interface shear lag effect. Based on the experimental and theoretical analyses, the formulas corresponding to different types of post-cast UHPC connections in prefabricated composite beams were proposed to calculate the longitudinal shear capacity, then the composition of equations and the reduction factors corresponding to different conditions were recommended.