Bearing Capacity Calculating of GFRP Tube Filled with Steel-Reinforced Concrete Composite Column Subjected to Eccentric Loading

2010 ◽  
Vol 163-167 ◽  
pp. 191-195
Author(s):  
Bai Ling Chen ◽  
Lian Guang Wang ◽  
Guo Peng Qin
Keyword(s):  
Reinforced Concrete ◽  
Bearing Capacity ◽  
Limit Equilibrium ◽  
Bending Rigidity ◽  
Composite Column ◽  
Composite Columns ◽  
Steel Reinforced Concrete ◽  
Steel Bar ◽  
Tensile Zone ◽  
Positive Effect

GFRP tube filled with steel-reinforced concrete composite column, GSRC, is a new kind of composite column, in which the (shaped steel) reinforcing steel bar is set and the concrete is poured into GFRP tube. Under the action of eccentric loading, the damage signs of the composite columns with smaller and larger eccentricity were respectively that GFRP tube of compressive zone was crushed and the fiber of GFRP tube of tensional zone was ruptured. The tight hoop effect of the concrete given by GFRP tube only existed in compressive zone, and the restriction to the concrete of tensile zone was unobvious. The shaped steel inside GFRP tube had a positive effect on the bending rigidity and the bearing capacity of the member. Using the limit equilibrium theory, the calculation formula of the bearing capacity of GSRC subjected to eccentric loading was created. The calculated results agreed well with the experimental ones.

scholarly journals Analysis and Modification of Methods for Calculating Axial Load Capacity of High-Strength Steel-Reinforced Concrete Composite Columns

Materials ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 6860
Author(s):  
Jun Wang ◽  
Yuxin Duan ◽  
Yifan Wang ◽  
Xinran Wang ◽  
Qi Liu
Keyword(s):  
Reinforced Concrete ◽  
Bearing Capacity ◽  
High Strength Steel ◽  
Slenderness Ratio ◽  
High Strength ◽  
Confinement Effect ◽  
Test Results ◽  
Composite Columns ◽  
Steel Reinforced Concrete ◽  
Modified Formula

To investigate the applicability of the methods for calculating the bearing capacity of high-strength steel-reinforced concrete (SRC) composite columns according to specifications and the effect of confinement of stirrups and steel on the bearing capacity of SRC columns. The axial compression tests were conducted on 10 high-strength SRC columns and 4 ordinary SRC columns. The influences of the steel strength grade, the steel ratio, the types of stirrups and slenderness ratio on the bearing capacity of such members were examined. The analysis results indicate that using high-strength steel and improving the steel ratio can significantly enhance the bearing capacity of the SRC columns. When the slenderness ratio increases dramatically, the bearing capacity of the SRC columns plummets. As the confinement effect of the stirrups on the concrete improves, the utilization ratio of the high-strength steel in the SRC columns increases. Furthermore, the results calculated by AISC360-19(U.S.), EN1994-1-1-2004 (Europe), and JGJ138-2016(China) are too conservative compared with test results. Finally, a modified formula for calculating the bearing capacity of the SRC columns is proposed based on the confinement effect of the stirrups and steel on concrete. The results calculated by the modified formula and the finite element modeling results based on the confinement effect agree well with the test results.

On the Stress-Strain of Steel Tube Column Filled with Steel-Reinforced Concrete Subject to Compression-Flexure Loading

2011 ◽  
Vol 71-78 ◽  
pp. 3855-3860
Author(s):  
Xiao Liu ◽  
Min Li
Keyword(s):  
Reinforced Concrete ◽  
Bearing Capacity ◽  
Axial Compression ◽  
Compression Ratio ◽  
Limit Equilibrium ◽  
Steel Tube ◽  
Stress Strain ◽  
Peak Displacement ◽  
Steel Reinforced Concrete ◽  
Axial Compression Ratio

In order to study the bearing capacity and section stress-strain distribute on the steel tube filled with steel-reinforced concrete (STSRC) compression-flexure column, four compression-flexure members of STSRC were tested and theoretical researched. The major parameters of the test were axial compression ratio (n=0.5~0.85). The result of the study showed that: load-deformation() typical curve includes three stages, elastic characteristic, elastic-plastic characteristic, and disruption; Along with the increase of axial compression ratio, the bearing capacity and ductility reduced, but the peak displacement had not change enough; The composite column conformed to plane section, and the larger the axial compression ratio, the further distance of neutral axis of section to the centric axis and closer to the tensile region. ; During the loading process, the steel skeleton in compressive zone yield, but in tensile region never yielded. According to the test results and the limit equilibrium method, the formula for calculating the compression-flexure member of STSRC was established. A good agreement between the calculation results and testing results illustrates, which is feasible to using the calculating formula to calculate the bearing capacity of STSRC.

scholarly journals The Investigation on Mechanical Performances of High-Strength Steel Reinforced Concrete Composite Short Columns under Axial Load

Materials ◽  
2022 ◽  
Vol 15 (1) ◽  
pp. 329
Author(s):  
Jun Wang ◽  
Xinran Wang ◽  
Yuxin Duan ◽  
Yu Su ◽  
Xinyu Yi
Keyword(s):  
Reinforced Concrete ◽  
Bearing Capacity ◽  
High Strength Steel ◽  
Axial Load ◽  
High Strength ◽  
Composite Columns ◽  
Steel Reinforced Concrete ◽  
Steel Ratio ◽  
Short Columns ◽  
Calculation Results

At present, the existing standards (AISC360-16, EN1994-1-1:2004, and JGJ138-2016) lack relevant provisions for steel-reinforced concrete (SRC) composite columns with high-strength steel. To investigate the axial compressive mechanical performance of short high-strength steel-reinforced concrete (HSSRC) columns, the axial load test was conducted on 12 short composite columns with high-strength steel and ordinary steel. The influences of steel strength, steel ratio, and the section form of steel on the failure modes, bearing capacity, and ductility of the specimens were studied. Afterward, the experimental data were compared with the existing calculation results. The results show: compared with the specimens with Q235 steel, the bearing capacity of the specimens with Q460 steel increases by 7.8–15.3%, the bearing capacity of the specimens with Q690 steel increases by 13.2–24.1%, but the ductility coefficient increases by 15.2–202.4%; with the increase of steel ratio, the bearing capacity and ductility of specimens are significantly improved. A change of the steel cross-section could influence the ductility of SRC columns more than their bearing capacity. Moreover, the calculation results show that present standards could not predict the bearing capacity of HSSRC columns. Therefore, a modified method for determining the effective strength of steel equipped in HSSRC columns was proposed. The results of the ABAQUS simulation also showed that the addition of steel fibers could significantly improve the bearing capacity of Q690 HSSRC columns. The research results provide a reference for engineering practices.

Analysis on Deformation of Pre-Splitting Steel Reinforced Concrete Beams Strengthened by Prestressed CFRP

2011 ◽  
Vol 243-249 ◽  
pp. 929-933
Author(s):  
Na Ha ◽  
Lian Guang Wang ◽  
Shen Yuan Fu
Keyword(s):  
Reinforced Concrete ◽  
Bearing Capacity ◽  
Concrete Beams ◽  
Bending Moment ◽  
Reinforced Concrete Beams ◽  
Steel Reinforced Concrete ◽  
Cfrp Sheets ◽  
Deformation Curves ◽  
Prestressed Cfrp Sheets ◽  
Theoretical Results

In order to improve the bearing capacity of SRC which is related with deformation and stiffiness, SRC beams should be strengthened by CFRP. Based on the experiment of six pre-splitting steel reinforced concrete beams strengthened with (Prestressed) CFRP sheets, the deformation of beams are discussed. Load-deformation curves are obtained by the experiment. Considering the influence of intial bending moment on SRC beams, the calculated deformation formulas of SRC beams strengthened by (Prestressed) CFRP are deduced. The results showed that the load-deformation curves of normal and strengthened beams respectively showed three and two linear characteristics. The theoretical results which calculated by the formulas of deformation are well agreement with the experimental results.

scholarly journals Comparative Study of CFRP-Confined CFST Stub Columns under Axial Compression

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Ying Guo ◽  
Yufen Zhang
Keyword(s):  
Comparative Study ◽  
Bearing Capacity ◽  
Limit Equilibrium ◽  
Concrete Strength ◽  
Confinement Effect ◽  
Unified Theory ◽  
Enhancement Ratio ◽  
Composite Columns ◽  
Cfst Columns ◽  
Stub Columns

This paper presented a comparative study of concrete-filled steel tubular (CFST) stub columns with three different confinement types from carbon fiber reinforced polymer (CFRP): outer circular CFRP, inner circular CFRP, and outer square CFRP. The compressive mechanism and physical properties of the composite column were analyzed firstly aiming at investigating the confinement effect of CFRP. Ultimate axial bearing capacity of these three CFRP-confined CFST columns was calculated based on Unified Theory of CFST and elastoplastic limit equilibrium theory, respectively. Meanwhile, the corresponding tests are adopted to validate the feasibility of the two calculation models. Through data analysis, the study confirmed the ultimate strength calculation results of the limit equilibrium method were found to be more reliable and approximate to the test results than those of Unified Theory of CFST. Then axial bearing capacity of the pure CFST column was predicted to evaluate the bearing capacity enhancement ratio of the three types of composite columns. It was demonstrated that the averaged enhancement ratio is 16.4 percent, showing that CFRP-confined CFST columns had a broad engineering applicability. Through a comparative analysis, this study also confirmed that outer circular CFRP had the best confinement effect and outer square CFRP did better than inner circular CFRP. The confinement effect of CFRP increased with the decrease of concrete strength, and it was proportional with relative proportions of CFRP and steel under the same concrete strength.

Calculation of Ultimate Bearing Capacity of Prestressed Steel Reinforced Concrete Structure under Fire

2011 ◽  
Vol 250-253 ◽  
pp. 2857-2860 ◽  
Author(s):  
Yu Zhuo Wang ◽  
Chuang Guo Fu
Keyword(s):  
Reinforced Concrete ◽  
Bearing Capacity ◽  
Fire Resistance ◽  
Concrete Structure ◽  
Concrete Beam ◽  
Reinforced Concrete Beam ◽  
Ultimate Bearing Capacity ◽  
Reinforced Concrete Structure ◽  
Steel Reinforced Concrete ◽  
Resistance Performance

Prestressed steel reinforced concrete structure, compared with other concrete structure has its unique advantages. So it is mainly used in large span and conversion layers. With the popularization of this structure,more attention should be payed on fire resistance performance. On the basis of reasonable assume,two steps model is used as concrete high strength calculation model. Simplified intensity decreased curve is used as rebar,steel and prestressed. Two ultimate bearing capacity formulas of prestressed steel reinforced concrete beam are established. One is for the beam whose tensile area is under fire, the other is for the beam whose compression area is under fire. Prestressed steel reinforced concrete structure has both prestressed concrete structure’s advantages and steel reinforced concrete structure ’s advantage. Steel reinforced concrete is used to improve the bearing capacity of the structure. Prestressed steel is used to improve the ultimate state of structure’s performance during normal use. Thereby structure’s performance is better to play. There are many similarities between prestressed steel reinforced concrete structure and steel reinforced concrete structure about fire resistance performance. Because of prestressed steel reinforced concrete structure’s own characteristics, there are still many problems about fire resistance. This paper mainly presented bending terminal bearing capacity of prestressed steel reinforced concrete beam under fire. Established simplified formulae for calculation, it is meet the engineering accuracy requirement.

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