scholarly journals A Novel Precast Concrete Beam–Column Connection With Replaceable Energy-Dissipation Connector: Experimental Investigation and Theoretical Analysis

Author(s):  
Chao Tong ◽  
Jing Wu ◽  
Chunyu Li

Abstract In order to avoid the damage of the connection due to the overstrength of beam strength, and the alternation of the strength hierarchy in the structural system. The additional bending moment produced by the combined action of the pressure generated by the concrete compression zone and the tension generated by the reinforcements needs to be reduced. A novel precast concrete beam–column connection is proposed herein. In the proposed connection, the precast beam is laid on a steel corbel embedded in the precast column. A novel replaceable energy-dissipation connector (REDC) is placed at the bottom of the steel corbel, which ensures that it is in the same horizontal position aligned with the longitudinal reinforcement at the bottom of the connection. In addition, there is a narrow vertical slot adjacent to the column face. The total yield capacity of the top reinforcement is larger than that of the bottom REDC energy-dissipation connector. Theory study focused on the structural features and mechanical mechanism of this novel precast connection. Three low-cycle quasi-static loading tests were carried out on a single full-scaled specimen by replacing three REDCs with different sizes. The cracking pattern of this novel precast connection, and the effects of different parameters of the REDCs on the energy-dissipation capacity and load capacity of the connections were discussed. By performing a finite-element simulation, a method for reducing the additional bending moment and keeping the top reinforcements always in elastic was developed. In addition, the relevant design suggestions were provided. The conclusion shows that the seismic performance of this novel precast concrete beam–column connection is excellent. The positive and negative bending moments of novel precast concrete beam–column connection both reduce the additional bending moment. In view of this, the bending moment of the novel connection is a controllable variable.

2012 ◽  
Vol 626 ◽  
pp. 85-89 ◽  
Author(s):  
Kay Dora Abdul Ghani ◽  
Nor Hayati Hamid

The experimental work on two full-scale precast concrete beam-column corner joints with corbels was carried out and their seismic performance was examined. The first specimen was constructed without steel fiber, while second specimen was constructed by mixed up steel fiber with concrete and placed it at the corbels area. The specimen were tested under reversible lateral cyclic loading up to ±1.5% drift. The experimental results showed that for the first specimen, the cracks start to occur at +0.5% drifts with spalling of concrete and major cracks were observed at corbel while for the second specimen, the initial cracks were observed at +0.75% with no damage at corbel. In this study, it can be concluded that precast beam-column joint without steel fiber has better ductility and stiffness than precast beam-column joint with steel fiber. However, precast beam-column joint with steel fiber has better energy dissipation and fewer cracks at corbel as compared to precast beam-column joint without steel fiber.


2020 ◽  
Vol 23 (13) ◽  
pp. 2822-2834
Author(s):  
Xian Rong ◽  
Hongwei Yang ◽  
Jianxin Zhang

This article investigated the seismic performance of a new type of precast concrete beam-to-column joint with a steel connector for easy construction. Five interior beam-to-column joints, four precast concrete specimens, and one monolithic joint were tested under reversed cyclic loading. The main variables were the embedded H-beam length, web plate or stiffening rib usage, and concrete usage in the connection part. The load–displacement hysteresis curves were recorded during the test, and the behavior was investigated based on displacement ductility, deformability, skeleton curves, stiffness degradation, and energy dissipation capacity. The results showed that the proposed beam-to-column joint with the web plate in the steel connector exhibited satisfactory behavior in terms of ductility, load capacity, and energy dissipation capacity under reversed cyclic loading, and the performance was ductile because of the yielding of the web plate. Therefore, the proposed joint with the web plate could be used in high seismic regions. The proposed joint without the web plate exhibited similar behavior to the monolithic specimen, indicating that this joint could be used in low or moderate seismic zones. Furthermore, the utilization of the web plate was vital to the performance of this system.


2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Vera Agustriana Noorhidana ◽  
John P. Forth

Abstract Three equivalent exterior precast concrete beam-column (PCBC) connections have been investigated in this study in orderto analyze the effect of steel fiber reinforced concrete (SFRC) as cast-in-place (CIP) on the seismic performance of the PCBC connection. The connection was designed as a ductile connection for a moment-resisting frame and consists of a precast U-beam, precast column with corbel, interlocking bars, and CIP-concrete to connect the precast beam to precast column. The volume fractions of steel fiber incorporated within the CIP-concrete were 0%, 0.5% and 1%. A quasi-static load was applied vertically to the beam tip of the PCBC specimen. The results showed that the steel fibers contained within the CIP-concrete provided 2% increase of the maximum load, 17.7% increase of the energy dissipation, and increase in the joint stiffness of the PCBC connection. The steel fibers delayed the onset of cracking and slowed down the crack propagation, resulting in shorter cracks in the joint core of PCBC specimen, which correlates well with the deflection-hardening characteristic found from the modulus of rupture test.


2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Shujun Hu ◽  
Qi Guo ◽  
Xinfu Xiong ◽  
Jingang Xiong

A new type of prefabricated reinforced concrete-Y-shaped eccentrically steel brace structure (PRC-Y-ESBS) is developed by combining the mechanical property of prefabricated reinforced concrete frame and Y-shaped eccentrically steel brace, so the seismic performance and seismic resilience capacity of prefabricated reinforced concrete frame can be effectively improved. In the PRC-Y-ESBS, the precast concrete beam-to-shear link composite connection should have enough bearing capacity and resilience capacity under the shear force and bending moment, so the damage can be restricted in shear links. In this paper, an innovative precast concrete beam-to-shear link composite connection (PCB-SLCC) with bending moment and shear force separate method is proposed. Four different types of shear connectors are analyzed in detail by using the verified numerical method, and the shear capacity and failure mode of shear connectors can be obtained. Then, the innovative PCB-SLCCs with the reasonable shear connector considering different influencing parameters are also studied in detail. The results indicate that the shear connectors and high-strength bolts are still in elastic state at ultimate load, and little damage has occurred in the concrete between the embedded plate and precast concrete frame, while the PCB-SLCC has enough bearing capacity at the ultimate stage. In addition, this study also clearly identifies that high-strength bolts can only bear the bending moment, and the shear force is only carried by shear connectors, so the bending moment and shear force of the innovative PCB-SLCC with high bearing capacity, ease of installation, and seismic resilience capacity can be apparently separated.


Author(s):  
Yadong Li ◽  
Fangfang Geng ◽  
Youliang Ding ◽  
Libin Wang

The self-centering precast concrete frame structure combines the advantages of industrialization and low earthquake damage, and its energy dissipation capacity and seismic performance have always been the focus of research. This paper proposed a kind of self-centering precast concrete frame with hysteretic dampers (SCPCHD). Its modular design makes the energy dissipation device and components easy to repair and replace. In order to obtain the optimal design, the finite element models of SCPCHD frames with different layout types of post-tensioned (PT) tendons and different shapes of hysteretic dampers are established, and the elastoplastic dynamic time-history analyses are carried out. The results show that the layout types and vertical margin of PT tendons have little effect on the displacement response of the frame structure. Compared to linear PT tendons, polygonal PT tendons can better bear the bending moment of the beam and reduce the stress of longitudinal reinforcements in the beam. The reduce effect of shortening the vertical margin on the tensile damage of beam concrete is obvious in the frame with polygonal PT tendons, but not obvious in the frame with linear PT tendons. Rational design of the prestressing force also plays a crucial role in the energy dissipation capacity of SCPCHD frames.


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