Cyclic loading test for reinforced concrete columns with continuous rectangular and polygonal hoops

2014 ◽  
Vol 67 ◽  
pp. 39-49 ◽  
Author(s):  
Tae-Sung Eom ◽  
Su-Min Kang ◽  
Hong-Gun Park ◽  
Tae-Woo Choi ◽  
Jong-Min Jin
Keyword(s):  
Reinforced Concrete ◽  
Cyclic Loading ◽  
Concrete Columns ◽  
Loading Test ◽  
Reinforced Concrete Columns ◽  
Cyclic Loading Test

Experimental study of as-built and composite materials retrofitted reinforced concrete columns

2005 ◽  
Vol 32 (2) ◽  
pp. 454-460 ◽  
Author(s):  
Shuenn-Yih Chang ◽  
I-Chau Tsai
Keyword(s):  
Reinforced Concrete ◽  
Cyclic Loading ◽  
Carbon Fibre ◽  
Seismic Design ◽  
Concrete Columns ◽  
Loading Test ◽  
General Design ◽  
Cyclic Loading Test ◽  
Design Requirements ◽  
Strength And Stiffness

Four full-size reinforced concrete columns as used in school buildings were cast and tested under reversed cyclic loading. Test results of the two as-built columns confirm that the hysteresis behaviours of a column are considerably improved if special seismic design provisions are used in addition to general design requirements instead of using general design requirements only. Although lateral strength and stiffness are not increased, ductility increases and pinching decreases in hysteretic loops. It is also found that the column conformed to general design requirements can be effectively retrofitted by wrapping with either carbon fibre fabrics or carbon fibre reinforced polymer (CFRP) L-shaped plates if its lateral confinement is upgraded to the same level as that designed based on special seismic design provisions. This retrofitting of lateral confinement is effective at improving the ductility of a column and mitigating the strength degradation, stiffness degradation, and pinching in the hysteretic loops, although the strength and stiffness of the column are not increased.Key words: CFRP L-shaped plate, carbon fibre fabric, retrofit, cyclic loading test.

SEISMIC PERFORMANCE OF GFRP-RC RECTANGULAR COLUMNS: NUMERICAL STUDY

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Ehab El-Salakawy ◽  
Fangxin Ye ◽  
Yasser Mostafa Selmy
Keyword(s):  
Reinforced Concrete ◽  
Cyclic Loading ◽  
Axial Load ◽  
Numerical Study ◽  
Concrete Strength ◽  
Weight Ratio ◽  
Concrete Columns ◽  
Load Level ◽  
Reinforced Concrete Columns ◽  
Rectangular Columns

Composite materials like glass fiber-reinforced polymer (GFRP) is becoming widely acceptable to be used as a reinforcing material due to its high ultimate tensile strength-to-weight ratio and excellent resistance to corrosion. However, the seismic behavior of GFRP-reinforced concrete columns has not been fully investigated yet. This paper presents the results of a numerical analysis of full-size GFRP-RC rectangular columns under cyclic loading. The simulated column depicts the lower part of a building column between the foundation and the point of contra-flexure at the mid-height of the column. GFRP reinforcement properties and concrete modeling based on fracture energy have been incorporated in the numerical model. Experimental validation has been used to examine the accuracy of the constructed finite element models (FEMs) using a commercially available software. The validated FEM was used to perform a parametric study, considering several concrete strength values and axial load levels, to study its influence on the performance of the GFRP-reinforced concrete columns under cyclic loading. It was concluded that the hysteretic dissipation capacity deteriorates under high axial load level due to severe softening of the concrete. The FE results showed a substantial improvement of the lateral load-carrying capacities by increasing concrete compressive strength.

High-strength bar reinforced concrete walls: Cyclic loading test and strength prediction

2019 ◽  
Vol 198 ◽  
pp. 109508 ◽  
Author(s):  
Xiangyong Ni ◽  
Shuangyin Cao ◽  
Shuai Liang ◽  
Yizhu Li ◽  
Yang Liu
Keyword(s):  
Reinforced Concrete ◽  
Cyclic Loading ◽  
High Strength ◽  
Strength Prediction ◽  
Loading Test ◽  
Concrete Walls ◽  
Cyclic Loading Test ◽  
Reinforced Concrete Walls

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.

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