Local compressive behavior of joint core reinforced with ring beam for connection of polyvinyl chloride fiber‐reinforced polymer confined concrete column and reinforced concrete beam

Abstract

In this paper, seven specimens were designed to study the influence of the height (h), width (b), and reinforcement ratio (ρ) of ring beam on the failure mode, bearing capacity, deformation, and equivalent stress–strain relation of joint core reinforced with ring beam for connection of polyvinyl chloride fiber‐reinforced polymer confined concrete column and reinforced concrete beam. The experimental results indicated that the crushing of concrete in the joint core dominated the failure of specimens. The ultimate, yield bearing capacity and axial strain decreased with the increase of height, while raised with the improvement of width or reinforcement ratio. The growth of the strains of reinforcement and concrete accelerated with the increment of height, while decelerated with the rise of width or reinforcement ratio. Subsequently, based on the local compression theory, confined concrete theory, and the principle of superposition of multiple confinement, considering the influence coefficient of joint height βh and the enhancement coefficient of stirrups αs, a new formula was proposed to estimate the ultimate bearing capacity of specimens under axial local compression. Then, on the basis of Mander's model, taking the correction parameter η into consideration, a new model of equivalent stress–strain relationship was established. Verification results showed that the models proposed in this research agreed well with the experimental results.

Shear capacity estimation of core steel tube reinforced PCCC column-beam interior joint under quasi-static load

“…However, PCCC column-beam interior joints present unsatisfactory fire resistance and need to be further improved. From the perspective of locally enhanced joint core region, the steel mesh joint (Yu F et al, 2020), enlarged ring beam joint (Bu SS et al, 2020) and core steel tube (CST) joint (Yu F et al, 2020), were proposed for the connection between PCCC columns and RC beams. Subsequently, the author’s research group carried out a systematic study on PCCC column-enlarged ring beam joints, including axial compression (Yu F et al, 2019), eccentric compression (Yu F, Feng CC et al, 2020), and seismic behaviors (Song ZK et al, 2021).…”

Axial compression behavior of reinforced concrete beam to square thin‐walled concrete‐filled steel tube column joints stiffened by internal diaphragms

“…In through-column joints, 13,14 the beam reinforcing bars were connected to the stiffeners welded on columns; the steel tube was continuous through the joint zone, and thus the strong-joint weak-component under axial compression was satisfied, namely, the axial load capacity of the joint zone was larger than that of the CFST column. In through-beam joints, [15][16][17][18][19][20] the beam reinforcing bars were continuous through the joint zone; the steel tube was completely disconnected in the joint zone, and the ring beams consisting of multiple lateral hoops were used to make up for the reduction in load capacity. Consequently, the axial behavior of the through-beam joints was mainly focused on.…”