scholarly journals Seismic Behavior of Concrete-Filled Steel Tube (CFST) Column and Reinforced Concrete (RC) Beam Connections under Reversed Cyclic Loading

2021 ◽  
Vol 53 (3) ◽  
pp. 210301
Author(s):  
Ahmed Najm Abdullah ◽  
Bambang Budiono ◽  
Herlien Dwiarti Setio ◽  
Erwin Lim

Previous studies on the connection between concrete-filled steel tube (CFST) columns and reinforced concrete (RC) beams have shown a loss of joint confinement because the steel tube was completely or partially cut in the joint area. This research presents a new connection system that provides joint confinement through a continuous steel tube. Potential sliding shear at the smooth interface between the columns and beams in the joint face is mitigated using two mechanisms: (i) shear connectors and (ii) longitudinal web beam reinforcement. This study tested two CFST column and RC beam joints to 4.5% drift ratio under combined compression axial load and lateral cyclic load. The experimental results revealed no cracks at the joint zone and the specimens satisfied the ACI 374.1-05 criteria, despite minor sliding at the beam-column interface. The finite element (FE) model showed good agreement with the experimental results.

2013 ◽  
Vol 351-352 ◽  
pp. 138-142
Author(s):  
Zhi Bin Wang ◽  
Li Ying Liu

Concrete-filled steel tube reinforced concrete (CFSTRC) columns are currently being studied as a popular method to improve the shear strength, the ductility and the seismic behaviour of reinforced concrete (RC) columns. Owing to the complexity of confinement provided by steel tubes and stirrups, the behaviour of CFSTRC column is difficult to be accurately simulated. Thus,so far there is not a finite element (FE) model for CFSTRC columns. For studying the performance of this composite column, a FE model was developed based on the existing test results and theories. The predicted results using this FE model agree with the test results, which means that this model can be applied to carry out the further mechanism analysis.


2016 ◽  
Vol 857 ◽  
pp. 159-164
Author(s):  
P.N. Anupama ◽  
Mathew Anu ◽  
Kavya K. Kumar

The concrete filled steel tubular (CFST) columns consist of steel tube in-filled with concrete. The connections are the most important components of a CFST column and reinforced concrete beam structural system, since it combines the beams and the columns. In this paper, a through-beam ring connection for strengthening the joint between CFST column and RC beam is modeled using the finite element software package ANSYS and analysed the axial compressive behavior of the connection system. The numerical model is validated with the results available in the literature to confirm the structural efficiency of the ring beam connection system.


2014 ◽  
Vol 16 (2) ◽  
pp. 187-201 ◽  
Author(s):  
Chunyu Tian ◽  
Congzhen Xiao ◽  
Tao Chen ◽  
Xueyi Fu

A combination of outstanding advantages of concrete filled steel tube (CFST) column with reinforced concrete (RC) flat slab creates the effective and potential structure to replace traditional reinforced concrete frame structures in high-rise buildings. The CFST column – RC slab connection is the key factor for this structure type to work properly and effectively. Currently, the studies mainly focus on inner CFST column and RC slab connection, there are very few experimental studies on connection of edge or corner CFST columns and RC flat slab. This paper proposes edge and corner CFST columns to RC flat slab connection structures using H-shaped shear head and then conducts two large size tests to investigate behaviors of the connection.


2021 ◽  
Vol 232 ◽  
pp. 111910
Author(s):  
Lucas Ribeiro dos Santos ◽  
Rodrigo Barreto Caldas ◽  
Lucas Figueiredo Grilo ◽  
Hermes Carvalho ◽  
Ricardo Hallal Fakury

2009 ◽  
Vol 417-418 ◽  
pp. 833-836 ◽  
Author(s):  
Qing Xiang Wang ◽  
Shi Run Liu

The test results of six connections under cyclic loading are presented in the paper. Each test specimen was properly designed to model the interior joint of a moment resisting frame, and was identically comprised of three parts that including the circular concrete filled steel tube columns, the reinforced concrete beams, and the short fabricated connection stubs. Energy dissipation was designed to occur in the beams during a severe earthquake. Steel bars which were embedded into concrete core and welded to the connection stubs, were used to transfer the force distributed by the reinforcing bars of concrete beam to the concrete core. The results indicated that the embedded steel bars were very efficient in eliminating the stress concentration on the tube wall and there was no visible deformation occurred on the tube wall until the collapse of the specimen. Furthermore, the connection of each specimen had enough capacity and thus the plastic hinge appeared in the beams. As results, the ductility of this new type structure directly depended on the RC beams.


2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Yiyan Lu ◽  
Tao Zhu ◽  
Shan Li ◽  
Weijie Li ◽  
Na Li

This paper investigates the axial behavior of slender reinforced concrete (RC) columns strengthened with concrete filled steel tube (CFST) jacketing technique. It is realized by pouring self-compacting concrete (SCC) into the gap between inner original slender RC columns and outer steel tubes. Nine specimens were prepared and tested to failure under axial compression: a control specimen without strengthening and eight specimens with heights ranging between 1240 and 2140 mm strengthened with CFST jacketing. Experimental variables included four different length-to-diameter (L/D) ratios, three different diameter-to-thickness (D/t) ratios, and three different SCC strengths. The experimental results showed that the outer steel tube provided confinement to the SCC and original slender RC columns and thus effectively improved the behavior of slender RC columns. The failure mode of slender RC columns was changed from brittle failure (concrete peel-off) into ductile failure (global bending) after strengthening. And, the load-bearing capacity, material utilization, and ductility of slender RC columns were significantly enhanced. The strengthening effect of CFST jacketing decreased with the increase of L/D ratio and D/t ratio but showed little variation with higher SCC strength. An existing expression of load-bearing capacity for traditional CFST columns was extended to propose a formula for the load-bearing capacity of CFST jacketed columns, and the predictions showed good agreement with the experimental results.


2012 ◽  
Vol 204-208 ◽  
pp. 930-933
Author(s):  
Xiao Hu ◽  
Zhen Lin Chen

The paper introduces 3 types of uniaxial stress-strain relationships of concrete filled steel tube by Pan Youguang, Susantha and Saenz, and performs finite element analyses of the axial strengths of 18 CTRC columns, studies the characters of three models, and comprises between the axial strengths from FEA and existed experiments. Results show these 3 types of model are all suitable for bearing analysis, but Pan’s model is more accurate.


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