Analysis and Summary of Characteristics of Confined Concrete

2012 ◽  
Vol 174-177 ◽  
pp. 330-335
Author(s):  
Yun Da Shao ◽  
Hong Guo
Keyword(s):  
Bearing Capacity ◽  
Steel Tube ◽  
Confined Concrete ◽  
Concrete Filled Steel Tube ◽  
Capacity Model

Characteristics and constraint mechanism of concrete confined by ties,concrete filled steel tube,FRP-strengthened concrete were summed up in this paper,and unified bearing capacity model for confined concrete was also introduced,then several new kinds of confined concrete forms were outlined,finally the development and application of confined concrete were prospected.

The Influence of Bearing Capacity of Self-Stressed CFST Members for Different Strength Grades and Self-Stressed Magnitudes of Concrete

2012 ◽  
Vol 174-177 ◽  
pp. 1546-1551 ◽  
Author(s):  
Shui Xing Zhou ◽  
Yue Ma ◽  
Dong Sheng Sun ◽  
Lu Li ◽  
Cheng Wu
Keyword(s):  
Finite Element ◽  
Bearing Capacity ◽  
Concrete Strength ◽  
Steel Tube ◽  
The Self ◽  
Confined Concrete ◽  
Constitutive Relationship ◽  
Unified Theory ◽  
Concrete Filled Steel Tube ◽  
Relationship Model

According to the unified theory of general concrete filled steel tube, this paper puts forward a constitutive relationship model of the self-stressed concrete filled steel tube, which was verified by experiments and finite element methods. On the basis of the above, the influences on the bearing capacity of self-stressed CFST members were analyzed about the strength grades and magnitudes of self-stress of confined concrete. The results show that the bearing capacity of the self-stressed concrete filled steel tube members will be improved with the increase of the magnitudes of self-stress and concrete strength grades. Compared to the general CFST in the same condition, the maximum of the bearing capacity can be approximately enhanced 20%.

scholarly journals Bearing capacity calculation of eccentrically compressed concrete filled steel tube columns taking into account non-linear diagrams of materials

2021 ◽  
Vol 18 (1) ◽  
pp. 36-45
Author(s):  
A. A. Vedernikova ◽  
◽  
Eh. K. Opbul ◽  
Keyword(s):  
Bearing Capacity ◽  
Compressive Force ◽  
Steel Tube ◽  
Confined Concrete ◽  
Tube Steel ◽  
Deformation Model ◽  
Practical Calculation ◽  
Nonlinear Method ◽  
Concrete Filled Steel Tube ◽  
Maximum Curvature

The article provides an example of practical calculation of eccentrically compressed steel tube confined concrete using a nonlinear deformation model taking into account the standard deformation diagrams of materials. The calculation was performed on the example of a test specimen made of concrete filled steel tube (steel tube confined concrete) using the method of sequential approximation based on iterative procedures. The nonlinear method is aimed at making deformation assessment of the element bearing capacity by searching for the calculated deformation at particular points of the normal section at its maximum curvature and comparison with the standard admissible values. The task of iterative calculations is assessing the value of the maximum curvature of eccentrically compressed steel tube confined concrete which is under the action of a longitudinal compressive force. The basic calculation formulas are given. Comparison with the results of numerical and analytical calculations has shown a good convergence.

Influencing Factors of Self-Stressed Concrete Filled Steel Tube with Segments Bearing Capacity

2013 ◽  
Vol 676 ◽  
pp. 60-64
Author(s):  
Shi Liang Wang ◽  
Li Yun Yi
Keyword(s):  
Finite Element ◽  
Bearing Capacity ◽  
Concrete Strength ◽  
Steel Tube ◽  
The Self ◽  
Confined Concrete ◽  
Constitutive Relationship ◽  
Unified Theory ◽  
Concrete Filled Steel Tube ◽  
Relationship Model

According to the unified theory of general concrete filled steel tube, this paper puts forward a constitutive relationship model of the self-stressed concrete filled steel tube, which was verified by experiments and finite element methods. On the basis of the above, the influences of the bearing capacity of self-stressed CFST members were analyzed about the strength grades and magnitudes of self-stress of confined concrete. The results show that the bearing capacity of the self-stressed concrete filled steel tube members will be improved with the increase of the magnitudes of self-stress and concrete strength grades. Compared to the general CFST in same conditions, the maximum extent of the bearing capacity can be approximately enhanced 20%.

Coupled ultimate capacity of CFRP confined concrete-filled steel tube columns under compression-bending-torsion load

Structures ◽  
2021 ◽  
Vol 31 ◽  
pp. 558-575
Author(s):  
Yu-Hang Wang ◽  
Yu-Yan Wang ◽  
Xu-Hong Zhou ◽  
Ran Deng ◽  
Yong-Sen Lan ◽  
...  
Keyword(s):  
Steel Tube ◽  
Confined Concrete ◽  
Ultimate Capacity ◽  
Concrete Filled Steel Tube

Bearing capacity of composite shear wall incorporating a concrete-filled steel tube boundary and column-type reinforced wall

2020 ◽  
Vol 23 (10) ◽  
pp. 2188-2203
Author(s):  
Zhao Nannan ◽  
Wang Yaohong ◽  
Han qing ◽  
Su Hao
Keyword(s):  
Bearing Capacity ◽  
Residual Deformation ◽  
Shear Walls ◽  
Shear Wall ◽  
Steel Tube ◽  
Concrete Filled Steel Tube ◽  
Composite Shear Wall ◽  
Boundary Shear ◽  
Column Type ◽  
Composite Shear

Composite shear walls are widely used in high-rise buildings because of their high bearing capacity. To improve the bearing capacity of ordinary shear walls, restraining elements are usually installed at both boundaries or within the wall body. In this article, two different restraining elements, namely, a rectangular steel tube and a column-type reinforcement (the whole wall body was restrained by segmented stirrups and tied by diagonal bars), were applied to the boundary frame and wall body of the shear wall either jointly or separately. A new type of steel-concrete composite shear wall, referred to as a composite shear wall incorporating a concrete-filled steel tube boundary and column-type reinforced wall, was proposed. In addition, three specimens with different restraining elements, namely, a column-type reinforced shear wall, a concrete-filled steel tube boundary shear wall and an ordinary reinforced concrete shear wall, were presented for comparison. The influences of the two different restraining elements on the seismic performance and bearing capacity of the shear walls were analyzed from four perspectives of failure mode, hysteresis behavior, stiffness and residual deformation, and the equivalent lateral pressures of the two restraining elements were calculated. Based on the plane-section assumption, expressions for the crack, yield, peak and ultimate bearing capacities were derived, and the effects of the two restraining elements on the peak and ultimate bearing capacities were considered. The results show that these two restraining elements significantly improved the bearing capacity of the shear wall specimens, and the concrete-filled steel tube restraining element was more effective than the column-type reinforced restraining element. Finally, the calculated values of the bearing capacity of the four different restraining elements of the shear wall specimens proposed in this article were in good agreement with the experimental values.

Study of the Ultimate Bearing Capacity of Concrete-filled Steel Tube K-Joints

2019 ◽  
Vol 23 (5) ◽  
pp. 2254-2262 ◽  
Author(s):  
Kaizhong Xie ◽  
Hongwei Wang ◽  
Jinhao Pang ◽  
Jianxi Zhou
Keyword(s):  
Bearing Capacity ◽  
Steel Tube ◽  
Ultimate Bearing Capacity ◽  
Concrete Filled Steel Tube

Axial behaviour of slender concrete-filled steel tube square columns strengthened with square concrete-filled steel tube jackets

2019 ◽  
Vol 23 (6) ◽  
pp. 1074-1086 ◽  
Author(s):  
Tao Zhu ◽  
Hongjun Liang ◽  
Yiyan Lu ◽  
Weijie Li ◽  
Hong Zhang
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Bearing Capacity ◽  
Element Model ◽  
Steel Tube ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
Concrete Filled Steel Tube ◽  
Experimental Parameters ◽  
Modified Formula

This article investigates the behaviour of slender concrete-filled steel tube square columns strengthened by concrete-filled steel tube jacketing. The columns were realised by placing a square outer steel tube around the original slender concrete-filled steel tube column and pouring strengthening concrete into the gap between the inner and outer steel tubes. Three concrete-filled steel tube square columns and seven retrofitted columns ranging from 1200 to 2000 mm were tested to failure under axial compression. The experimental parameters included three length-to-width ( L/ B1) ratios, three width-to-thickness ( B1/ t1) ratios and three strengths of concrete jacket (C50-grade, C60-grade and C70-grade). Experimentally, the retrofitted columns failed in a similar manner to traditional slender concrete-filled steel tube columns. After strengthening, the retrofitted columns benefitted greatly from the component materials, with their load-bearing capacity and ductility notably enhanced. These enhancements were mainly brought about by sectional enlargement and good confinement of concrete. A finite element model was developed using ABAQUS to better understand the axial behaviour of the retrofitted specimens. A parametric study was conducted, with parameters including the length of the column, thickness of the outer steel tube, strength of the concrete jacket, yield strength of the outer steel tube, thickness of the inner steel tube and strength of the inner concrete. Furthermore, the finite element model was adopted to study the behaviour of rust-damaged and post-fire slender concrete-filled steel tube square columns strengthened by square concrete-filled steel tube jacketing. A modified formula was proposed to predict the load-bearing capacity of retrofitted specimens, and the numerical results agreed well with the experiments and the finite element results of undamaged, rust-damaged and post-fire specimens. It could be used as a reference for practical application.

scholarly journals The Horizontal Bearing Capacity of Composite Concrete-Filled Steel Tube Piles

2020 ◽  
Vol 2020 ◽  
pp. 1-15
Author(s):  
Yunxiu Dong ◽  
Zhongju Feng ◽  
Haibo Hu ◽  
Jingbin He ◽  
Qilang Zhang ◽  
...  
Keyword(s):  
Bearing Capacity ◽  
Soil Compaction ◽  
Soil Mass ◽  
Steel Tube ◽  
Continuous Increase ◽  
Concrete Filled Steel Tube ◽  
Concrete Piles ◽  
Compaction Zone ◽  
Reinforced Concrete Piles ◽  
Centrifugal Model

Steel casings (SCs) are extensively and increasingly used to stabilize the borehole wall in the construction of bridge pile foundations. Steel casings (SCs), together with reinforced concrete piles (RCPs), form composite concrete-filled steel tube piles (CCFSTPs), which differ significantly from ordinary RCPs in horizontal bearing capacity. In this study, based on the characteristics of CCFSTPs, the horizontal bearing capacity of a CCFSTP was examined through a centrifugal model test with the length of the steel casing (LSC) and the modulus of the soil mass in the steel casing soil compaction zone (ESCSC_zone) as variables. Pile-side soil resistance, load-displacement curves, and pile moment curves were obtained for the CCFSTP. The results show that increasing LSC within a range of 12 cm significantly increases the ultimate horizontal bearing capacity of the CCFSTP, and further increasing LSC beyond 12 cm produces a continuous increase in the ultimate horizontal bearing capacity of the CCFSTP but only to an insignificant extent. In addition, increasing ESCSC_zone increases the ultimate horizontal bearing capacity of the CCFSTP, but to a relatively small extent. The results of this study provide a theoretical basis and technical support for the design and construction of CCFSTPs.

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