Behaviour of Concrete Filled Steel Tube Reinforced Concrete (CFSTRC) Stub Columns: Experiments

2012 ◽  
Vol 166-169 ◽  
pp. 859-862 ◽  
Author(s):  
Yong Jin Li ◽  
Qing Xin Ren ◽  
Fei Yu Liao

Concrete filled steel tube (CFST) reinforced concrete (CFSTRC) columns subjected to axial compression were experimentally investigated in this paper. A total of ten specimens were tested. The main parameters varied in the experiments were steel tube ratio and concrete strength. It was found that, under axial compression, the column ultimate strength increases with the increasing of steel tube ratio and concrete strength. The work in this paper provides a basis for the further theoretical study on the behavior of CFSTRC columns.

2014 ◽  
Vol 578-579 ◽  
pp. 772-775
Author(s):  
Wan Qing Yu ◽  
Qing Xin Ren ◽  
Lian Guang Jia

In this paper, a further research has been carried on mechanical properties of concrete filled steel tube reinforced concrete columns after exposure to fire. A finite element analysis (FEA) model for concrete filled steel tube reinforced concrete columns after exposure to fire under axial compression is developed by ABAQUS. The temperature of cross-section element after exposure to fire has been obtained. The FEA model of temperature field is then used to investigate the mechanism of such composite columns further. Influences of parameters on Load-bearing Capacity such as fire duration time and steel ratio were analyzed. The work in this paper provides a basis for further theoretical study on concrete filled steel tube reinforced concrete columns after exposure to fire.


2014 ◽  
Vol 488-489 ◽  
pp. 704-707
Author(s):  
Ying Wang ◽  
Miao Li ◽  
Jin Hua Xu ◽  
He Fan

Based on finite element analysis o f concrete filled steel tube beam-column joints under the single axial compression ratio and concrete strength, further research was done to analyze the seismic performance of concrete filled steel tube beam-column joints under different axial compression ratio and concrete strength. Beam-column joint which is connected by bolts with welding extended steel sheets at the beam root was analyzed. The results show that with the increase of axial compression ratio, strength and stiffness degradation of the joint accelerated gradually. Axial compression ratio at 0.3, 0.4 are appropriate values for joints specimen, load-displacement hysteresis curve of joint specimens is relatively plump and shows good seismic performance. Chance of concrete strength also had effect on seismic performance of joint specimen, but in contrast it is not so obviously.


2021 ◽  
Vol 2021 ◽  
pp. 1-18
Author(s):  
Jing Ji ◽  
Maomao Yang ◽  
Zhichao Xu ◽  
Liangqin Jiang ◽  
Huayu Song

The behavior of H-shaped honeycombed stub columns with rectangular concrete-filled steel tube flanges (STHCCs) subjected to axial load was investigated experimentally. A total of 16 specimens were studied, and the main parameters varied in the tests included the confinement effect coefficient of the steel tube (ξ), the concrete cubic compressive strength (fcu), the steel web thickness (t2), and the slenderness ratio of specimens (λs). Failure modes, load-displacement curves, load-strain curves of the steel tube flanges and webs, and force mechanisms were obtained by means of axial compression tests. The parameter influences on the axial compression bearing capacity and ductility were then analyzed. The results showed that rudder slip diagonal lines occur on the steel tube outer surface and the concrete-filled steel tube flanges of all specimens exhibit shear failure. Specimen load-displacement curves can be broadly divided into elastic deformation, elastic-plastic deformation, and load descending and residual deformation stages. The specimen axial compression bearing capacity and ductility increase with increasing ξ, and the axial compression bearing capacity increases gradually with increasing fcu, whereas the ductility decreases. The ductility significantly improves with increasing t2, whereas the axial compression bearing capacity increases slightly. The axial compression bearing capacity decreases gradually with increasing λs, whereas the ductility increases. An analytical expression for the STHCC short column axial compression bearing capacity is established by introducing a correction function ( w ), which has good agreement with experimental results. Finally, several design guidelines are suggested, which can provide a foundation for the popularization and application of this kind of novel composite column in practical engineering projects.


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.


2018 ◽  
Vol 38 ◽  
pp. 03035
Author(s):  
Ji Zhong Wang ◽  
Lu Cheng ◽  
Xin Pei Wang

A new column of FRP composite tube confined steel-reinforced concrete (FTCSRC) column was proposed. This paper elaborates on laboratorial and analytical studies on the behavior of FCTSRC columns subjected to axial compressive load. Eight circular FTCSRC stub columns and one circular steel tube confined concrete (STCC) stub column were tested to investigate the failure mode and axial compression performance of circular FTCRSC columns. Parametric analysis was implemented to inquire the influence of confinement material (CFRP-steel tube or CFRP-GFRP tube), internal steel and CFRP layers on the ultimate load capacity. CFRP-steel composite tube was composed of steel tube and CFRP layer which was wrapped outside the steel tube, while CFRP-GFRP composite tube was composite of GFRP tube and CFRP layer. The test results indicate that the confinement effect of CFRP-steel tube is greatly superior to CFRP-GFRP tube. The ductility performance of steel tube confined high-strength concrete column can be improved obviously by encasing steel in the core concrete. Furthermore, with the increase in the layers of FRP wraps, the axial load capacity increases greatly.


PLoS ONE ◽  
2021 ◽  
Vol 16 (9) ◽  
pp. e0255603
Author(s):  
Ni Zhang ◽  
Chenyang Zheng ◽  
Qingwei Sun

The reinforced concrete-filled steel tube (RCFST) column solves several of the problems of the concrete-filled steel tube (CFST) column in practical engineering applications. Moreover, RCFST has a simple joint structure, high bearing capacity, good ductility, and superior fire resistance. From a structural safety perspective, designers prioritize the creep performance of CFST members in structural design. Therefore, the creep behavior of RCFST columns should be thoroughly investigated in practical engineering design. To study the influence of the creep behavior of RCFST columns under axial compression, this work analyzed the mechanical behavior of composite columns based on their mechanical characteristics under axial compression and established a creep formula suitable for RCFST columns under axial compression. A creep analysis program was also developed to obtain the creep strain–time curve, and its correctness was verified by existing tests. On this basis, the effects of the main design parameters, such as the stress level, steel ratio, and reinforcement ratio, on the creep behavior were determined and analyzed. The creep of the tested composite columns increased rapidly in the early stages (28 days) of load action; the growth rate was relatively low after 28 days and tended to stabilize after approximately six months. The stress level had the greatest influence on the creep of RCFST columns under axial compression, followed by the steel ratio. The influence of the reinforcement ratio on the creep behavior was less. The results of this study can provide a reference for engineering practice.


2016 ◽  
pp. 94-108 ◽  
Author(s):  
Xiao-Xiong Zha ◽  
◽  
Xiao-Li Li ◽  
Ning Wang ◽  
Cheng-Yong Wan ◽  
...  

2012 ◽  
Vol 446-449 ◽  
pp. 82-85
Author(s):  
Chuang Du ◽  
Xiao Ming Yang ◽  
Ning Li Li

In this paper, a comparative investigation into the behavior of concrete-filled steel tube column and reinforced concrete column with the same quantity of material and cross-section sizes under axial load have been undertaken using the finite element method. Both is analyzed to compare the axial compression performance,including bearing capacity, ductility and their mechanism. The results of the analyses clearly exhibit that bearing capacity of concrete-filled steel tube column is higher about 25% than that of reinforced concrete column. Under the same conditions, ductility of concrete-filled steel tube column is better than reinforced concrete column, its application is recommended in construction practice.


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