Effect of the Outer Diameter on the Behavior of Square RC Columns Strengthened with Self-Compacting Concrete Filled Circular Steel Tube

2018 ◽  
Vol 19 (3) ◽  
pp. 1042-1054 ◽  
Author(s):  
Yiyan Lu ◽  
Zhenzhen Liu ◽  
Shan Li ◽  
Xiaobo Zhao
Keyword(s):  
Steel Tube ◽  
Outer Diameter ◽  
Self Compacting Concrete ◽  
Rc Columns ◽  
Circular Steel Tube

Experimental Study on Concrete-Filled Double Skin Circular Steel Tubular Beams under Bending Load

2020 ◽  
Vol 995 ◽  
pp. 136-142
Author(s):  
Seung Jo Lee ◽  
Jung Min Park
Keyword(s):  
Concrete Strength ◽  
Maximum Load ◽  
Steel Tube ◽  
Outer Diameter ◽  
Steel Tubes ◽  
Displacement Ductility ◽  
Circular Steel Tube ◽  
Bending Load ◽  
Pattern Maximum ◽  
Behavior Characteristics

This paper examines the structural and mechanical behavior characteristics of the concrete-filled double circular steel tube (CFDT) fabricated with the installation of shape memory alloys (SMAs) and reinforcement bars in the inner and outer steel tubes, the inner-outer diameter ratio (Di/Do), and the concrete strength as the main variables. Towards this end, the displacement ductility, crack patterns, load-central deflection relationship, displacement ductility, and flexural shear strength were compared and analyzed. The results verified that a change in the Di/Do has significant effects on the crack pattern, maximum load, and ductility. The specimens with SMAs installed between the inner and outer steel tubes generally showed good results.

scholarly journals Experimental Research on Reinforced Concrete Columns Strengthened with Steel Jacket and Concrete Infill

2021 ◽  
Vol 11 (9) ◽  
pp. 4043
Author(s):  
Aleksandar Landović ◽  
Miroslav Bešević
Keyword(s):  
Compressive Strength ◽  
Reinforced Concrete ◽  
Cross Section ◽  
Experimental Research ◽  
Failure Modes ◽  
Steel Tube ◽  
Rc Columns ◽  
Rc Column ◽  
Steel Jacket ◽  
Ductile Behavior

Experimental research on axially compressed columns made from reinforced concrete (RC) and RC columns strengthened with a steel jacket and additional fill concrete is presented in this paper. A premade squared cross-section RC column was placed inside a steel tube, and then the space between the column and the tube was filled with additional concrete. A total of fourteen stub axially compressed columns, including nine strengthened specimens and five plain reinforced concrete specimens, were experimentally tested. The main parameter that was varied in the experiment was the compressive strength of the filler concrete. Three different concrete compression strength classes were used. Test results showed that all three cross-section parts (the core column, the fill, and the steel jacket) worked together in the force-carrying process through all load levels, even if only the basic RC column was loaded. The strengthened columns exhibited pronounced ductile behavior compared to the plain RC columns. The influence of the test parameters on the axial compressive strength was investigated. In addition, the specimen failure modes, strain development, and load vs. deformation relations were registered. The applicability of three different design codes to predict the axial bearing capacity of the strengthened columns was also investigated.

C80 Early Strength Micro Expansion of Steel Tube Reinforced Concrete Research

2015 ◽  
Vol 1119 ◽  
pp. 752-755
Author(s):  
Chang Zheng Sun ◽  
Zheng Wang
Keyword(s):  
High Performance ◽  
Raw Materials ◽  
Influence Factors ◽  
High Strength ◽  
Steel Tube ◽  
Strength Analysis ◽  
Self Compacting Concrete ◽  
Mix Proportion ◽  
Early Strength ◽  
Working Performance

Optimization of mix proportion parameter ，Using ordinary raw materials makes a C80 high performance self-compacting concrete;By joining a homemade perceptual expansion agent, significantly improve the early strength of concrete and effective to solve the high strength of self-compacting concrete caused by gelled material consumption big contraction;Further study on the working performance of high-strength self-compacting concrete, age strength, analysis the influence factors of concrete are discussed.

scholarly journals Axial Behaviour of Slender RC Circular Columns Strengthened with Circular CFST Jackets

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Yiyan Lu ◽  
Tao Zhu ◽  
Shan Li ◽  
Weijie Li ◽  
Na Li
Keyword(s):  
Bearing Capacity ◽  
Ductile Failure ◽  
Steel Tube ◽  
Experimental Results ◽  
Strengthening Effect ◽  
Load Bearing Capacity ◽  
Rc Columns ◽  
Load Bearing ◽  
Cfst Columns ◽  
Material Utilization

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.

Springback law of high-strength 21-6-9 stainless steel tube in numerical control bending under different process parameters

2015 ◽  
Vol 231 (10) ◽  
pp. 1783-1792 ◽  
Author(s):  
Jun Fang ◽  
Shiqiang Lu ◽  
Kelu Wang ◽  
Zhengjun Yao
Keyword(s):  
Stainless Steel ◽  
Friction Coefficient ◽  
Cross Section ◽  
Process Parameters ◽  
High Strength ◽  
Steel Tube ◽  
Numerical Control ◽  
Stainless Steel Tube ◽  
Outer Diameter ◽  
The Cross

In order to achieve the precision bending deformation, the effects of process parameters on springback behaviors should be clarified preliminarily. Taking the 21-6-9 high-strength stainless steel tube of 15.88 mm × 0.84 mm (outer diameter × wall thickness) as the objective, the multi-parameter sensitivity analysis and three-dimensional finite element numerical simulation are conducted to address the effects of process parameters on the springback behaviors in 21-6-9 high-strength stainless steel tube numerical control bending. The results show that (1) springback increases with the increasing of the clearance between tube and mandrel Cm, the friction coefficient between tube and mandrel fm, the friction coefficient between tube and bending die fb, or with the decreasing of the mandrel extension length e, while the springback first increases and then remains unchanged with the increasing of the clearance between tube and bending die Cb. (2) The sensitivity of springback radius to process parameters is larger than that of springback angle. And the sensitivity of springback to process parameters from high to low are e, Cb, Cm, fb and fm. (3) The variation rules of the cross section deformation after springback with different Cm, Cb, fm, fb and e are similar to that before springback. But under same process parameters, the relative difference of the most measurement section is more than 20% and some even more than 70% before and after springback, and a platform deforming characteristics of the cross section deformation is shown after springback.

Experimental study on circular steel tube-confined reinforced UHPC columns under axial loading

2021 ◽  
Vol 230 ◽  
pp. 111599
Author(s):  
Jiangang Wei ◽  
Zhitao Xie ◽  
Wei Zhang ◽  
Xia Luo ◽  
Yan Yang ◽  
...  
Keyword(s):  
Experimental Study ◽  
Axial Loading ◽  
Steel Tube ◽  
Circular Steel Tube

scholarly journals Seismic Performance of Recycled Concrete Filled Circular Steel Tube Columns

2020 ◽  
Vol 7 ◽  
Author(s):  
Dingyi Xu ◽  
Zongping Chen ◽  
Chunheng Zhou
Keyword(s):  
Seismic Performance ◽  
Coarse Aggregate ◽  
Slenderness Ratio ◽  
Steel Tube ◽  
Recycled Concrete ◽  
Load Range ◽  
Equivalent Viscous Damping ◽  
Displacement Ductility ◽  
Recycled Coarse Aggregate ◽  
Circular Steel Tube

This study was conducted to experimentally investigate the behavior of recycled concrete-filled circular steel tube (RCFST) columns subjected to cyclic loading. Ten specimens were prepared and tested. Four parameters were used to characterize seismic behavior: the replacement percentage of recycled coarse aggregate, slenderness ratio, axial compression level, and steel ratio. A novel calculation method for the bearing capacity for RCFST columns is established. The failure processes and modes of RCFST columns are found to be similar to normal concrete-filled steel tube columns. Varying the replacement percentage of recycled coarse aggregate has little effect on the hysteresis curves of the RCFST columns. The RCFST columns also show seismic performance similar to that of concrete-filled steel tubes. The displacement ductility of all specimens is larger than 3.0 and the equivalent viscous damping coefficients corresponding to the ultimate load range from 0.305 to 0.460.

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