scholarly journals EXPERIMENTAL STUDIES ON ENHANCEMENT OF SEISMIC PERFORMANCE OF REINFORCED CONCRETE COLUMNS BASED ON ARRANGEMENT OF LONGITUDINAL REINFORCEMENT

2003 ◽  
pp. 1-14
Author(s):  
Jun-ichi HOSHIKUMA ◽  
Shigeki UNJOH ◽  
Kazuhiro NAGAYA ◽  
Akihiko SHIOJIMA
Keyword(s):  
Reinforced Concrete ◽  
Seismic Performance ◽  
Experimental Studies ◽  
Concrete Columns ◽  
Longitudinal Reinforcement ◽  
Reinforced Concrete Columns

scholarly journals Experimental analysis of reinforced concrete columns strengthened with Self-Compacting concrete

2010 ◽  
Vol 3 (3) ◽  
pp. 271-283 ◽  
Author(s):  
M. Y. M. Omar ◽  
R. B. Gomes ◽  
A. P. A. Reis
Keyword(s):  
Reinforced Concrete ◽  
Ultimate Load ◽  
Rectangular Cross Section ◽  
Concrete Columns ◽  
Loading Capacity ◽  
Longitudinal Reinforcement ◽  
Self Compacting Concrete ◽  
Reinforced Concrete Columns ◽  
Subsequent Test ◽  
Steel Bars

This paper presents the results of reinforced concrete columns strengthened by addition of a self-compacting concrete overlay at the compressed and at the tensioned face of the member, with and without addition of longitudinal steel bars. Eight columns were submit- ted to loading with an initial eccentricity of 60 mm . These columns had 120 mm x 250 mm of rectangular cross section, 2000 mm in length and four longitudinal reinforcement steel bars with 10 mm in diameter. Reference columns P1 and P2 were tested to failure without any type of rehabilitation. Columns P3 to P8 were loaded to a predefined load (close to the initial yield point of tension reinforce- ment), then unloaded and strengthened for a subsequent test until failure. Results showed that the method of rehabilitation used was effective, increasing the loading capacity of the strengthened pieces by 2 to 5 times the ultimate load of the reference column.

Experimental Study on Seismic Performance of RC Composite Core Walls with Steel Tube-Reinforced Concrete Columns and Concealed Steel Trusses under Eccentric Horizontal Loading

2010 ◽  
Vol 163-167 ◽  
pp. 2267-2273 ◽  
Author(s):  
Hong Ying Dong ◽  
Wan Lin Cao ◽  
Jian Wei Zhang
Keyword(s):  
Reinforced Concrete ◽  
Seismic Performance ◽  
Load Capacity ◽  
Concrete Columns ◽  
Steel Tube ◽  
Reinforced Concrete Columns ◽  
Deterioration Process ◽  
Combined Action ◽  
Process Energy ◽  
Steel Trusses

Two 1/6 scale core walls, including one RC core wall with steel tube-reinforced concrete columns and concealed steel trusses and one conventional RC core wall, were tested under eccentric horizontal cyclic loading. The load-capacity, ductility, hysteresis characteristics, stiffness, stiffness deterioration process, energy dissipation and damage characteristics of the two specimens were compared and discussed in this paper. It shows that the seismic performance of the RC core walls under combined action could be improved by setting the concealed steel trusses in the walls and using the steel tube-reinforced concrete columns as the boundary elements.

scholarly journals Size Effect on the Seismic Performance of High-Strength Reinforced Concrete Columns with Different Shear Span-to-Depth Ratios

2018 ◽  
Vol 2018 ◽  
pp. 1-19
Author(s):  
Chunyi Yu ◽  
Hua Ma ◽  
Yongping Xie ◽  
Zhenbao Li ◽  
Zhenyun Tang
Keyword(s):  
Reinforced Concrete ◽  
Size Effect ◽  
Seismic Performance ◽  
Factor Of Safety ◽  
Shear Failure ◽  
High Strength ◽  
Concrete Columns ◽  
Reinforced Concrete Columns ◽  
Local Factor ◽  
Shear Span

The size effect on the seismic performance of conventional reinforced concrete columns has been observed in terms of flexural failure and shear failure. Under earthquake loading, slender columns experience flexural failure, and short columns experience flexure-shear failure and shear failure. However, the effect of section size on the seismic performance of high-strength reinforced concrete columns under the conditions of different shear span-to-depth ratios requires further confirmation. For this purpose, six high-strength reinforced concrete columns with shear span-to-depth ratios of 2 and 4 were subjected to cyclic loading in this study. The experimental results indicated that relative nominal flexural strength, energy dissipation coefficient, factor of safety, and local factor of safety all exhibited a strong size effect by decreasing with increasing column size. Furthermore, the size effect became stronger as the shear span-to-depth ratio was increased, except for average energy dissipation coefficient. The observed changes in the factor of safety were in good agreement with the Type 2 size effect model proposed by Bažant. Thus, based on the local factor of safety and Bažant’s Type 2 model, the code equation for moment capacity of different shear span-to-depth ratios was modified to provide a consistent factor of safety regardless of column size.

scholarly journals Gravity Load Collapse Behavior of Nonengineered Reinforced Concrete Columns

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Chichaya Boonmee ◽  
Kittipoom Rodsin ◽  
Krissachai Sriboonma
Keyword(s):  
Reinforced Concrete ◽  
Cyclic Loading ◽  
Axial Load ◽  
Concrete Columns ◽  
Poor Quality ◽  
Load Level ◽  
Longitudinal Reinforcement ◽  
Reinforced Concrete Columns ◽  
Gravity Load ◽  
Collapse Behavior

This paper aims at investigating gravity load collapse behavior of extremely poor quality reinforced concrete columns under cyclic loading. Such columns were usually constructed by local people and may not be designed to meet any of the standards. It was found that their concrete strength may be as low as 5 MPa and the amount of longitudinal reinforcement may be lower than 1%. This type of column is deliberately defined as “nonengineered reinforced concrete column,” or NRCC. During earthquake, the gravity load collapse of the NRCC columns caused a large number of death tolls around the world. In this study, four columns as representative of existing NRCC were tested under cyclic loading. The compressive strength of concrete in order of 5 MPa was used to be representative of columns with poor quality concrete. Two axial load levels of 6 and 18 tons were used to study the influence of axial load level on maximum drift at gravity load collapse. To investigate the effect of bar types on drift capacity, 9 mm round bars were used in two specimens and 12 mm deformed bars were used for the rest of the specimens. The maximum drift before gravity load collapse was very dependent on the axial load level. The maximum drift of the specimens subjected to high axial load (18 tons) was extremely low at approximately 1.75% drifts. The use of deformed bars (associated with larger amount of longitudinal reinforcement) caused the damage to severely dissipate all over the height of the columns. Such damage caused columns to collapse at a lower drift compared to those using round bars. Finally, the plastic hinge model was used to predict the maximum drift of the low strength columns. It was found that the model overly underestimates the drift at gravity load collapse.

Seismic performance of reinforced concrete columns confined with two layers of stirrups

2018 ◽  
Vol 27 (12) ◽  
pp. e1484 ◽  
Author(s):  
Wei Li ◽  
Linzhu Sun ◽  
Junliang Zhao ◽  
Pengfei Lu ◽  
Fang Yang
Keyword(s):  
Reinforced Concrete ◽  
Seismic Performance ◽  
Concrete Columns ◽  
Reinforced Concrete Columns
Sign in / Sign up

Export Citation Format

Share Document