scholarly journals Study on the Mechanical Properties of BFRP Tube Confined Concrete Short Columns under Axial Compression

2020 ◽  
Author(s):  
Xindong Ding ◽  
Shuqing Wang ◽  
Yu Liu ◽  
Zepeng Zheng
Keyword(s):  
Axial Compression ◽  
Brittle Failure ◽  
Failure Modes ◽  
Concrete Strength ◽  
Steel Tube ◽  
Confined Concrete ◽  
Test Results ◽  
Compression Tests ◽  
Short Columns ◽  
Square Steel Tube

Axial compression tests were carried out on 6 square steel tube confined concrete short columns and 6 BFRP square pipe confined concrete axial compression tests. The concrete strength grades were C30, C40, and C50. The test results show that the failure modes of steel pipe and BFRP pipe are obviously different, and the BFRP pipe undergoes brittle failure. Compared with the short columns of concrete confined by BFRP pipes, the ultimate bearing capacity of axial compression is increased by -76.46%, -76.01%, and -73.06%, and the ultimate displacements are -79.20%, -80.78%, -71.71%.

scholarly journals Study on the Mechanical Properties of BFRP Tube Confined Concrete Short Columns under Axial Compression

2020 ◽  
Author(s):  
Xindong DING ◽  
Shuqing Wang ◽  
Yu Liu ◽  
Zepeng Zheng
Keyword(s):  
Axial Compression ◽  
Brittle Failure ◽  
Failure Modes ◽  
Concrete Strength ◽  
Steel Tube ◽  
Confined Concrete ◽  
Test Results ◽  
Compression Tests ◽  
Short Columns ◽  
Square Steel Tube

Axial compression tests were carried out on 6 square steel tube confined concrete short columns and 6 BFRP square pipe confined concrete axial compression tests. The concrete strength grades were C30, C40, and C50. The test results show that the failure modes of steel pipe and BFRP pipe are obviously different, and the BFRP pipe undergoes brittle failure. Compared with the short columns of concrete confined by BFRP pipes, the ultimate bearing capacity of axial compression is increased by -76.46%, -76.01%, and -73.06%, and the ultimate displacements are -79.20%, -80.78%, -71.71%.

scholarly journals Experimental Study on CFRP-Confined Circularized Concrete-Filled Square Steel Tube Short Columns

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Yuchuan Wen ◽  
Zhongjun Hu ◽  
Anningjing Li ◽  
Quanheng Li ◽  
Xuepeng Li ◽  
...  
Keyword(s):  
Concrete Strength ◽  
Concrete Columns ◽  
Steel Tube ◽  
Confined Concrete ◽  
Test Results ◽  
Stress Strain ◽  
Short Columns ◽  
Reinforced Polymer ◽  
Square Steel Tube ◽  
Strain Model

This study investigates the suitability of the circularization technique for strengthening square concrete-filled square steel tube (CFSST) short columns. A total of 16 specimens were tested under axial compression. The main parameters under investigation were concrete strength, the thickness of arc cement mortar layer components (CAM), and the layers of carbon fiber-reinforced polymer (CFRP) sheets. Test results indicated that the failure mode of CFRP-confined circularized CFSST (C-C-CFSST) columns was similar to that of CFRP-confined concrete columns. The CFRP-confined circularized strengthening method can increase confinement efficacy and reduce the stress concentration at the corners of CFSST columns. Three existing CFRP-confined concrete stress-strain models were evaluated using the test results. The predictions of the Lam and Teng stress-strain model agree well with the test data.

Analysis on Bearing Capacity of Solid Multibarrel Tube-Confined Concrete Short Columns (CHS Inner and SHS Outer) under Axial Compressive Load

2011 ◽  
Vol 255-260 ◽  
pp. 151-156 ◽  
Author(s):  
Zhao Qiang Zhang ◽  
Yong Yao
Keyword(s):  
Ultimate Load ◽  
Concrete Strength ◽  
Compressive Load ◽  
Steel Tube ◽  
Confined Concrete ◽  
Unified Strength Theory ◽  
Short Columns ◽  
Circular Steel Tube ◽  
Reduction Coefficient ◽  
Square Steel Tube

By introducing the reduction coefficient of concrete strength and the equivalent restriction reduction coefficient,the non-uniform confinement force of square steel tube to its core concrete is turned to that of equivalent circular steel tube. Then the ultimate load calculation formula for the solid multibarrel tube-confined concrete short columns (CHS inner and SHS outer) is derived based on the Unified Strength Theory(UST),in which the double restriction effect and the decrease of longitudinal stress because of the hoop tensile tension are considered. The influence of intermediate principal stress on the ultimate load is studied and the failure mechanism is discussed. The applicability of the formulas is testified and the results show that the formulas have significance in exerting material potential.

Impact Factors Study on Strength of Steel Tube Confined Concrete Columns under Axial Compression

2013 ◽  
Vol 639-640 ◽  
pp. 1069-1072
Author(s):  
Hao Xiong Feng ◽  
Wei Jian Yi
Keyword(s):  
Axial Compression ◽  
Theoretical Basis ◽  
Concrete Strength ◽  
Concrete Columns ◽  
Steel Tube ◽  
Confined Concrete ◽  
Impact Factors ◽  
Working Mechanism

This paper describes principle and working mechanism of the steel tube confined concrete, to analyze impact factors of steel tube confined concrete strength. By the studies, presents several solutions to improve the strength of steel tube confined concrete, fully execute the behavior of steel tube and filled-in-concrete, strengthen the interactions between steel tube and filled-in-concrete to provide theoretical basis for the design and use of steel tube confined concrete.

Seismic behavior of normal-strength concrete-filled precast high-strength concrete centrifugal tube columns

2019 ◽  
Vol 23 (4) ◽  
pp. 614-629
Author(s):  
Shaohua Zhang ◽  
Xizhi Zhang ◽  
Shengbo Xu ◽  
Xingqian Li
Keyword(s):  
Axial Compression ◽  
High Strength Concrete ◽  
Seismic Behavior ◽  
Failure Modes ◽  
Concrete Strength ◽  
High Strength ◽  
Test Results ◽  
Normal Strength Concrete ◽  
Strength Concrete ◽  
Normal Strength

This study reports the cyclic loading test results of normal-strength concrete-filled precast high-strength concrete centrifugal tube columns. Seven half-scale column specimens were tested under cyclic loads and axial compression loads to investigate their seismic behavior. The major parameters considered in the test included axial compression ratio, filled concrete strength, and volumetric stirrup ratio. The structural behavior of each specimen was investigated in terms of failure modes, hysteresis behavior, bearing capacity, dissipated energy, ductility, stiffness degradation, drift capacity, and strain profiles. Test results revealed that the concrete-filled precast high-strength concrete centrifugal tube column exhibited good integral behavior, and the failure modes of all columns were ductile flexural failures. Lower axial compression ratio and higher volumetric stirrup ratio resulted in more satisfactory ductile performance. In contrast, the filled concrete strength has a limited influence on the structural behavior of concrete-filled precast high-strength concrete centrifugal tube columns. Based on the limit analysis method, the calculation formula for the bending capacity of the concrete-filled precast high-strength concrete centrifugal tube column was developed, and the results predicted from the formulas were in good agreement with the experiment results.

Research on Bearing Capacity of Short Concrete Filled Double Skin Steel Tubes Columns under Axial Compression

2010 ◽  
Vol 168-170 ◽  
pp. 2154-2157
Author(s):  
Jing Yu Chen ◽  
Ying Hai
Keyword(s):  
Axial Compression ◽  
Ultimate Load ◽  
Concrete Columns ◽  
Steel Tube ◽  
Confined Concrete ◽  
Load Estimation ◽  
Test Results ◽  
Steel Tubes ◽  
Double Skin ◽  
Structural Engineers

The use of steel tube confined concrete columns has been the interests of many structural engineers. For investigation of the axially loading capacity of short concrete filled double skin tubes (CFDST) columns, axial compression loading experiments were carried on 9 short CFDST column samples. According to experimental results and with numerical analysis, an ultimate load estimation equation of CFDST column with one correction parameter is presented, the linear relation between the parameter and the inner-to-outer diameters ratio Di/Do is given out. The ultimate load estimation equation is validated by the test results of short CFDST column samples.

The Experimental Study on Concrete-Filled Thin-Walled Square Steel Tube Short Columns Fixed U-Shaped Steel Bars

2011 ◽  
Vol 94-96 ◽  
pp. 962-969
Author(s):  
Hai Chao Wang ◽  
Xi Quan Xu ◽  
Li Jun Zhou ◽  
Hong Ying Zhang ◽  
Feng Lian Yang
Keyword(s):  
Concrete Strength ◽  
Testing Machine ◽  
Steel Tube ◽  
Steel Plates ◽  
Compression Process ◽  
Buckling Mode ◽  
Short Column ◽  
Short Columns ◽  
Thin Walled ◽  
Square Steel Tube

Based on the compression characteristics of the concrete-filled thin-walled square steel tube short columns, the U-shaped tie bars are designed in this paper. The U-shaped tie bars and steel pipe walls are connected with each other in T-shape in order to enhance the local stability of the walls under pressure. According to the concrete strength C30/C35/C40 and the thickness of the steel plates 1.25mm/1.75mm/2.5mm,42 short-column specimens are made, and the size of all specimens is 200mm×200mm×690mm.The bearing capacity test is done by the 500-ton electro-hydraulic serve testing machine. The strain of U-shaped tie bar and thin-walled steel are tested, and then the whole curve of compression process is obtained. The results show that the U-shaped tie bar has a very good role in bonding, and has good effects on improving buckling mode and the ductility of the components significantly. Concrete-filled thin-walled square steel tube short column fixed U-shaped tie bar has advantages on stronger post- deformability and more applicable to configuration compared with existing research achievements, and can provide a reference for engineering design.

scholarly journals Performance of Special-Shaped Concrete-Filled Square Steel Tube Column under Axial Compression

2020 ◽  
Vol 2020 ◽  
pp. 1-16 ◽  
Author(s):  
Zhen Wang ◽  
Xuejun Zhou ◽  
Fangshuai Wei ◽  
Mingyang Li
Keyword(s):  
Yield Strength ◽  
Failure Modes ◽  
Slenderness Ratio ◽  
Concrete Strength ◽  
Local Buckling ◽  
Steel Tube ◽  
Element Analysis ◽  
Fea Model ◽  
Compressive Performance ◽  
Square Steel Tube

The axial compressive performance of novel L-shaped and T-shaped concrete-filled square steel tube (L/T-CFSST) column was assessed in this study. Ten L/T-CFSST columns were tested to failure under axial load. The experimental data were used to determine various failure modes, bearing capacities, and load-displacement curves. The test parameters included the section form, steel tube thickness, steel yield strength, and slenderness ratio. The axial compressive performance of the L/T-CFSST column proved favorable, and each square steel tube showed strong cooperative performance. The failure mode of the stub column specimen (H/D ≤ 3) was strength failure caused by local buckling of the steel tube and that of the medium-long column member (H/D > 3) was instability failure caused by overall bending of the specimen. A finite element analysis (FEA) model was established and successfully validated by comparison against the test results. Based on the FEA model, parametric analyses were conducted to investigate the effects of steel tube thickness, concrete strength, steel yield strength, and slenderness ratio. The ultimate loads obtained from the experiments and FEA were compared to the results calculated by the available design codes. A formula was established to calculate the axial compressive strength and stability bearing capacity of the L/T-CFSST column accordingly. The calculation results are in close agreement with the FEA and experimental results, and the proposed formula may provide a workable reference for practicing engineers.

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