CONFINING TRANSVERSE REINFORCEMENTS FOR CIRCULAR COMPOSITE HOLLOW RC COLUMN WITH INNER TUBE

2014 ◽  
Vol 1 (1) ◽  
Author(s):  
Deok Hee Won ◽  
Woo-Sun Park ◽  
Ji-Hye Seo ◽  
Nam-Hyung Lim ◽  
Taek Hee Han
Keyword(s):  
Calculation Method ◽  
Rational Design ◽  
Plastic Hinge ◽  
Concrete Core ◽  
Rc Columns ◽  
Displacement Ductility ◽  
Rc Column ◽  
Cover Concrete ◽  
Strength And Stiffness ◽  
Aashto Lrfd

The confining transverse reinforcement has been arranged in plastic hinge region to resist the lateral load, increasing the lateral confining effect in the substructure of the bridge. Columns increased the seismic performance by securing the stiffness and ductility. The calculation method of confining transverse reinforcements is reported in AASHTO-LRFD specification. This specification is only proposed for solid RC columns. In this reason, if this specification is applied to another column as composite column besides solid RC columns, a proper evaluation of the column cannot be done. In particular, composite hollow RC columns have limits for applying this specification. The composite hollow RC column consists of transverse longitudinal reinforcement, cover concrete, core concrete, and an inner tube inserted on hollow face. It increases the ductility, strength, and stiffness of the composite hollow RC column. This paper suggests a modified equation for an economical and rational design through an investigation of displacement ductility when applied to the existing specifications of the composite hollow RC column. Moreover, parametric study is performed for evaluating the detail behavior. Using these results, a calculation method of economic transverse reinforcements is proposed.

Axial Compression Test of RC Columns Consolidation with BFRP

2012 ◽  
Vol 166-169 ◽  
pp. 881-884
Author(s):  
Bao Rong Huo ◽  
Xiang Dong Zhang
Keyword(s):  
Comparative Study ◽  
Bearing Capacity ◽  
Axial Compression ◽  
Calculation Formula ◽  
Rc Columns ◽  
Displacement Ductility ◽  
Rc Column ◽  
Ductility Factor ◽  
Increase Rate ◽  
The Comparative Study

12 RC columns were made, including nine RC columns wrapped with BFRP, three RC columns without any reinforcement, to conduct the comparative study of axial compression. The result shows that the bearing capacity of the RC columns reinforced with the fibers increases obviously.The displacement ductility factor increases, but its increase rate becomes slow with increasing layers of fiber cloth, so the most economical layer number is 3. Based on the confinement mechanism of FRP cloth and the calculation formula of the bearing capacity for common RC column, the formula of the bearing capacity for reinforced RC column with BFRP cloth is proposed. The result of calculation basically tallies with the number in experiment.

DYNAMIC ANALYSIS OF BRIDGES WITH PLASTIC HINGES UNDER EXTREME EARTHQUAKES

2015 ◽  
Vol 2 (1) ◽  
Author(s):  
T. Y. Lee ◽  
K. J. Chung
Keyword(s):  
Plastic Hinge ◽  
Concrete Columns ◽  
Computational Method ◽  
Past Study ◽  
Plastic Hinges ◽  
Concrete Core ◽  
Cover Concrete ◽  
Deformable Bodies ◽  
Fiber Element ◽  
Isolated Bridge

This study is aimed to develop the model of fiber element in the Vector Form Intrinsic Finite Element (VFIFE) to analyze the plastic hinges of reinforced-concrete columns for bridges subjected to extreme earthquakes. The VFIFE, a new computational method, is adopted in this study because of the superior in managing the engineering problems with material nonlinearity, discontinuity, large deformation and arbitrary rigid body motions of deformable bodies. In the past study, a plastic hinge is idealized as a bilinear elastoplastic model with a fracture moment. In order to analyze the realistic behavior of the plastic hinge, especially in ultimate state, the fiber element is developed to simulate the plastic hinge by using stress-strain relations in cover concrete, core concrete and steel fibers. The developed fiber element is verified to be feasible and accurate through numerical simulation. A three-span-continuous isolated bridge is analyzed to investigate the function of the columns and unseating prevention devices and to predict the collapse situation of the whole bridge. In addition, the analysis results are compared between the fiber element and bilinear elastoplastic element.

Axial Compression Test and Capacity Caculation of RC Columns Consolidation with BFRP, CFRP

2011 ◽  
Vol 94-96 ◽  
pp. 481-484 ◽  
Author(s):  
Bao Rong Huo ◽  
Xiang Dong Zhang
Keyword(s):  
Bearing Capacity ◽  
Axial Compression ◽  
Calculation Formula ◽  
Rc Columns ◽  
Displacement Ductility ◽  
Rc Column ◽  
Ductility Factor ◽  
Increase Rate ◽  
The Difference ◽  
The Comparative Study

Abstract：Twenty-one RC columns were made, including nine RC columns wrapped with BFRP, nine RC columns wrapped with CFRP, three RC columns without any reinforcement, to conduct the comparative study of axial compression. The result shows that the bearing capacity of the RC columns reinforced with the fibers increases obviously. The bearing capacity of the RC columns with CFRP is higher than that with BFRP, but the difference is not obvious. The displacement ductility factor increases, but its increase rate becomes slow with increasing layers of fiber cloth, so the most economical layer number is 3. Based on the confinement mechanism of FRP cloth and the calculation formula of the bearing capacity for common RC column, the formula of the bearing capacity for reinforced RC column with BFRP cloth is proposed. The result of calculation basically tallies with the number in experiment.

Lateral Bearing Capacity and Stiffness Calculation Method of SRC-RC Columns

2019 ◽  
Vol 23 (5) ◽  
pp. 2158-2174 ◽  
Author(s):  
He Zhang ◽  
Pingzhou Cao ◽  
Kai Wu ◽  
Chao Xu ◽  
Lijian Ren
Keyword(s):  
Bearing Capacity ◽  
Calculation Method ◽  
Rc Columns

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.

Experimental Investigation for Horizontal Ultimate Bearing Capacity and Target Ductility Factor Improvement Results of the RC Column Reinforced by AFL with Damages

2014 ◽  
Vol 488-489 ◽  
pp. 497-500
Author(s):  
You Lin Zou ◽  
Pei Yan Huang
Keyword(s):  
Bearing Capacity ◽  
Ultimate Bearing Capacity ◽  
Test Results ◽  
Rc Columns ◽  
Static Test ◽  
Rc Column ◽  
Ductility Factor ◽  
Secant Stiffness ◽  
Function Relationship ◽  
Reversed Cyclic

Deem test results from the low reversed cyclic loading quasi-static test with 2 RC columns as the basic information of secant stiffness damage of the reference column and take use of the TMS instrument in the test to artificially make the damage percentage of secant stiffness of the RC column as 33%, 50% and 66%, 6 damaged columns in total; reinforce the 6 damaged columns and 2 undamaged ones under the same conditions with AFL, through quasi-static contrast test. Test results show that it is able to effectively boost horizontal ultimate bearing capacity and ductility deformability of the RC columns with AFL for reinforcement; besides, there is a linear function relationship between horizontal ultimate bearing capacity, target ductility factor, and damage percentage of secant stiffness.

Analysis of Seismic Performance of RC Frames with Centrally Reinforced Columns

2013 ◽  
Vol 671-674 ◽  
pp. 1319-1323
Author(s):  
Zi Xue Lei ◽  
Yu Hang Han ◽  
San Sheng Dong ◽  
Jun Qing Guo
Keyword(s):  
Seismic Performance ◽  
Cross Sections ◽  
Carrying Capacity ◽  
Pushover Analysis ◽  
Seismic Load ◽  
Load Carrying Capacity ◽  
Rc Columns ◽  
Rc Column ◽  
Rc Frames ◽  
Load Carrying

A centrally reinforced column is a new type of RC columns, formed by providing a reinforcement skeleton at the central part of the cross section of an ordinary RC column. Tests have shown that as compared with an ordinary RC column, this type of columns has a higher load carrying capacity and ductility. From the pushover analysis of a frame composed of ordinary RC columns and one consisting of centrally reinforced columns, their seismic performance under seismic load of 9-degree intensity was studied according to Chinese code, including target displacements, story-level displacements, interstory drifts, appearance and development of plastic hinges. The results indicate that although the dimensions of cross sections of columns in the frame with centrally reinforced columns are smaller than those of the ordinary frame, the former still has a higher overall load carrying capacity and seismic performance than the latter.

Experiment Study on Cyclic Behavior of Concrete Filled Steel Tube (CFST) Column-Reinforced Concrete (RC) Beam Connections

2009 ◽  
Vol 417-418 ◽  
pp. 833-836 ◽  
Author(s):  
Qing Xiang Wang ◽  
Shi Run Liu
Keyword(s):  
Reinforced Concrete ◽  
Tube Wall ◽  
Plastic Hinge ◽  
Steel Tube ◽  
Reinforced Concrete Beams ◽  
Cyclic Behavior ◽  
Concrete Core ◽  
Concrete Filled Steel Tube ◽  
Steel Bars ◽  
Moment Resisting

The test results of six connections under cyclic loading are presented in the paper. Each test specimen was properly designed to model the interior joint of a moment resisting frame, and was identically comprised of three parts that including the circular concrete filled steel tube columns, the reinforced concrete beams, and the short fabricated connection stubs. Energy dissipation was designed to occur in the beams during a severe earthquake. Steel bars which were embedded into concrete core and welded to the connection stubs, were used to transfer the force distributed by the reinforcing bars of concrete beam to the concrete core. The results indicated that the embedded steel bars were very efficient in eliminating the stress concentration on the tube wall and there was no visible deformation occurred on the tube wall until the collapse of the specimen. Furthermore, the connection of each specimen had enough capacity and thus the plastic hinge appeared in the beams. As results, the ductility of this new type structure directly depended on the RC beams.

scholarly journals Theoretical calculation method for crack resistance of jacketed RC columns

2019 ◽  
Vol 708 ◽  
pp. 012059 ◽  
Author(s):  
Pavlo Krainskyi ◽  
Pavlo Vegera ◽  
Roman Khmil ◽  
Zinoviy Blikharskyy
Keyword(s):  
Theoretical Calculation ◽  
Crack Resistance ◽  
Calculation Method ◽  
Rc Columns

The Seismic Design and Performance of Reinforced Concrete Beam-Column Knee Joints in Buildings

2003 ◽  
Vol 19 (4) ◽  
pp. 863-895 ◽  
Author(s):  
Leslie M. Megget
Keyword(s):  
Reinforced Concrete ◽  
New Zealand ◽  
Concrete Beam ◽  
Reinforced Concrete Beam ◽  
Knee Joints ◽  
Joint Zone ◽  
Displacement Ductility ◽  
Cover Concrete ◽  
Joint Shear ◽  
And Performance

The seismic performance of eleven half-scale and three full-sized reinforced concrete beam-column knee joints was tested under inelastic cyclic loading. Twelve joints were designed to the current New Zealand Concrete Standard, NZS 3101 while the remaining two were designed to the 1964 New Zealand Code, which contained few seismic provisions. All the 1995 designs approached or exceeded their nominal beam strengths in both directions and only degraded in strength at displacement ductility factors greater than 2, while the 1960 designs failed prematurely in joint shear at about 70% of the beam nominal strengths. Many of the half-scale joints failed when cover concrete split off in the joint zone, allowing loss of anchorage and slip of the top beam bars. Two full-scale joints were designed to carry the maximum specified code joint shear stress (0.2 fc′), and one subsequently failed due to joint shear when the concrete compressive strength did not reach the specified design value. A third full-size joint was tested with distributed beam reinforcement. This joint performed in a ductile manner to displacement ductility 4 but failed in the second cycle at that displacement, due to buckling of several rows of beam bars.

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