Axial Compression Performance Research of RPC Filled Steel Tube Columns Based on the Unified Strength Theory

2013 ◽  
Vol 351-352 ◽  
pp. 337-341
Author(s):  
Qian Zhu ◽  
Jun Hai Zhao ◽  
Yan Li ◽  
Peng Wu ◽  
Su Wang

With consideration of the intermediate principal stress,the calculation formula of bearing capacity of RPC filled steel tube columns under axial compression is deduced based on the twin shear unified strength theory. Combining with the bond-slip theory,new ultimate bearing capacity formula is derived with the highest regard for bond stress. Compared with the theoretical result and the experimental data,good agreement can be found. The results show that unified strength theory and the bond-slip theory are versatile in theoretical analysis of the column. The analysis results can be provided for the optimum design of RPC filled steel tube and the solution has an important practical value for engineering application.

2014 ◽  
Vol 584-586 ◽  
pp. 1155-1160
Author(s):  
Rong Zhou ◽  
Jun Hai Zhao ◽  
Xue Ying Wei

New progress of research and applications of CFRP at home and abroad are introduced in this paper. The circular concrete-filled tubular CFRP-steel stub column under axial loads is studied based on the unified strength theory in the paper. The effect of intermediate principal stress on the ultimate strength for the concrete-filled tubular CFRP-steel stub column have been investigated. The ultimate load calculation formula for the concrete-filled tubular CFRP-steel stub column is derived in this paper, and can be simplified for cases without CFRP. Compared with the solution obtained in this paper and the experimental results, the good agreement can be found. The effects of the intermediate shear stress, the cross-section deformation ratio and also the inner friction angle of the concrete are all considered in the theory analysis. The analysis result further tests the applicability of the unified strength theory in the field of concrete-filled CFRP-steel tube. It has an important theory value for engineering application.


2011 ◽  
Vol 94-96 ◽  
pp. 1205-1210
Author(s):  
Zhao Liu ◽  
Jun Hai Zhao

The mechanical behavior and ultimate bearing capacity of the circular bar-reinforced concrete filled steel tube (BRCFST) short columns under axial compression are analyzed in this paper based on the unified strength theory. Considering the restriction effect of steel tube and hoop bar on concrete, the calculation formula of bearing capacity of the column is deduced. Parametric studies are carried out to evaluate the effects of intermediate principal stresses, diameter-thickness ratio of steel tube and the stirrup ratio on the bearing capacity of the column. A good agreement is reached by comparing the results calculated by the formula with the test results. It is concluded that the unified strength theory is applicable in the theoretical analyses of the BRCFST columns.


2013 ◽  
Vol 690-693 ◽  
pp. 742-746
Author(s):  
Peng Wu ◽  
Jian Feng Xu ◽  
Jun Hai Zhao ◽  
Qian Zhu ◽  
Su Wang

Based on unified strength theory, the mechanical behavior of core-concrete of concrete-filled square steel tubular stub columns was analyzed. Through controlling the constraint effect between square steel tube and core-concrete by width-thickness ratio, the ultimate bearing capacity formula for concrete-filled square steel tubular stub columns under axial compression was proposed, and the influencing factors of which was also discussed. The rationality of proposed formula was proved from the comparison of the analytical results obtained in this paper and experimental data.


2010 ◽  
Vol 163-167 ◽  
pp. 4542-4545 ◽  
Author(s):  
Xin Zhong Li ◽  
Xue Ying Wei ◽  
Jun Hai Zhao

This paper presents the theoretical and experimental results of concrete-filled steel tube columns subjected to axially compression. A total of 6 specimens with outer square sections reinforced by inner cicular steel tube were constructed for experimental investigation. The ultimate strengths of the columns from tests were obtained. The theoretical strengths of the columns were also investigated based on unified strength theory, and compared with the test results. Good agreement can be observed from the comparison.


2012 ◽  
Vol 204-208 ◽  
pp. 4031-4037
Author(s):  
Gui Yun Xia ◽  
Jia Jun Li ◽  
Mei Liang Yang

Based on the unified strength theory presented by Maohong Yu, the calculating formula for the load-bearing capacity of concrete-filled double steel tube was derived. Through tests, the calculating load-bearing capacity results were compared with testing results, which agreed well. The change of load-bearing capacities with parameter k of the unified strength theory was discussed. It can be drawn that the load-bearing capacity of CFDST will increase with the increase of parameter b, but the increase is not obvious.


2013 ◽  
Vol 634-638 ◽  
pp. 2752-2756 ◽  
Author(s):  
Qing Yun Ge ◽  
Cai Mei Li ◽  
Fu Lian Yang ◽  
Feng Yan Qin

Based on the twin shear unified strength theory, considering the impact of the intermediate principal stress σ2 and the different effects of material’ tensile and compressive properties, this paper deduced the axial compressive bearing capacity formula of core column with high strength concrete filled steel tube. Compared the results of the paper with the test, both coincide in good condition. The results show the validity of the formula. The theoretical formula provides a theoretical basis in the project application and design on the core column with high strength concrete filled steel tube.


2011 ◽  
Vol 94-96 ◽  
pp. 820-825
Author(s):  
Sai Wu ◽  
Jun Hai Zhao ◽  
Xue Ying Wei

This paper based on the unified strength theory, analyzed the ultimate bearing capacity of the reinforced concrete columns combined with FRP under axial loads. First, analyzed the mechanical property of the RC columns combined with FRP. Second, based on the unified strength theory, deduced the three-direction compressive stress of the core concrete and got the unified formula for calculating the ultimate bearing capacity of RC columns combined with FRP. Last, compared the analytical results obtained in this paper with the relevant experimental data, good agreement can be found and it proved the good applicability of the formula. Comparing with other methods in calculating the ultimate bearing capacity of RC columns combined with FRP,this method is well-founded, so it has a significant value in analysis of RC columns combined with FRP.


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.


Energies ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4831
Author(s):  
Hao Sun ◽  
Qingyuan Xu ◽  
Pengfei Yan ◽  
Jianguang Yin ◽  
Ping Lou

In order to study the axial compression performance of the T-shaped multi-cavity concrete-filled steel tube shear wall, first, three specimens were designed to perform the axial compression test. Then three-dimensional finite element analysis by the ABAQUS software was used to obtain the axial bearing capacity of the shear wall with different parameters. According to the results of the finite element model, the computational diagram in the limit state was obtained. The diagram was simplified into the core concrete in the non-enhanced area that was not constrained by the steel tube and the core concrete in the enhanced area that was uniformly constrained by the steel tube. Finally, a new practical equation for calculating the axial bearing capacity of a multi-cavity concrete-filled steel tubular shear wall was deduced and proposed based on the theory of ultimate equilibrium. The calculation results of the proposed equation were in good agreement with the finite element results, and the proposed equation can be used in practical engineering design.


2016 ◽  
Vol 2016 ◽  
pp. 1-11
Author(s):  
Hua Huang ◽  
Kailin Xi ◽  
Yu Zhang ◽  
Jinghui Shi ◽  
Boquan Liu

The load carrying capacity and failure mechanism of 8 square columns strengthened with high-performance ferrocement laminate (HPFL) and bonded steel plates (BSP) were analyzed on the basis of experiments on the axial compression performance of these columns. Results show that the reinforcing layer worked together with the original columns as a whole, and the load-bearing capacity significantly increased. When failure of the strengthened column occurred, the mortar and concrete were crushed and bulged outward in the middle of the columns, the angle bars and longitudinal steel bars buckled, and some stirrups were pulled out. The chamfering of angle bar momentously affected the primary damage of steel strand. The values of the strength reduction factor and pressure effective utilization coefficient of the mortar were suggested. Based on the experiments and existing tests of 35 columns strengthened with HPFL, equations for the axial compression bearing capacity were proposed and all calculation results agreed well with testing results. Therefore, the calculation method could be used in the capacity design of axial compression strengthened columns.


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