scholarly journals Shear Strength Model for Reinforced Concrete Columns with Low Transverse Reinforcement Ratios

2014 ◽  
Vol 17 (10) ◽  
pp. 1373-1385 ◽  
Author(s):  
Cao Thanh Ngoc Tran ◽  
Bing Li
Keyword(s):  
Shear Strength ◽  
Reinforced Concrete ◽  
Axial Load ◽  
Concrete Columns ◽  
Transverse Reinforcement ◽  
Reinforced Concrete Column ◽  
Reinforced Concrete Columns ◽  
Existing Structures ◽  
Reversed Cyclic ◽  
Constant Axial Load

This paper introduces an equation developed based on the strut-and-tie analogy to predict the shear strength of reinforced concrete columns with low transverse reinforcement ratios. The validity and applicability of the proposed equation are evaluated by comparison with available experimental data. The proposed equation includes the contributions from concrete and transverse reinforcement through the truss action, and axial load through the strut action. A reinforced concrete column with a low transverse reinforcement ratio, commonly found in existing structures in Singapore and other parts of the world was tested to validate the assumptions made during the development of the proposed equation. The column specimen was tested to failure under the combination of a constant axial load of 0.30 f' c A g and quasi-static cyclic loadings to simulate earthquake actions. The analytical results revealed that the proposed equation is capable of predicting the shear strength of reinforced concrete columns with low transverse reinforcement ratios subjected to reversed cyclic loadings to a satisfactory level of accuracy

Seismic Evaluation of Existing Reinforced Concrete Building Columns

1996 ◽  
Vol 12 (4) ◽  
pp. 715-739 ◽  
Author(s):  
Abraham C. Lynn ◽  
Jack P. Moehle ◽  
Stephen A. Mahin ◽  
William T. Holmes
Keyword(s):  
Reinforced Concrete ◽  
Axial Load ◽  
Lateral Displacement ◽  
Concrete Columns ◽  
Vertical Load ◽  
Seismic Evaluation ◽  
Severe Damage ◽  
Reinforced Concrete Columns ◽  
Concrete Building ◽  
Constant Axial Load

Past earthquakes have emphasized the vulnerability of reinforced concrete columns having details typical of those built before the mid-1970's. These columns are susceptible to axial-flexural, shear, and bond failures, which subsequently may lead to severe damage or collapse of the building. Research was undertaken to investigate the lateral and vertical load-resisting behavior of reinforced concrete columns typical of pre-1970's construction. Eight full-scale specimens were constructed and were loaded with constant axial load and increasing cyclic lateral displacement increments until failure. Test data are presented and compared with behavior estimated by using various evaluation methods.

scholarly journals The use of Grade 380 steel for transverse confining reinforcement in columns

1987 ◽  
Vol 20 (2) ◽  
pp. 99-115
Author(s):  
F. A. Zahn ◽  
R. Park ◽  
M. J. N. Priestley
Keyword(s):  
Reinforced Concrete ◽  
Axial Load ◽  
Analytical Study ◽  
Concrete Columns ◽  
Lateral Loading ◽  
Transverse Reinforcement ◽  
Reinforced Concrete Columns ◽  
Ductility Factor ◽  
Strain Behaviour ◽  
Curvature Ductility

The results of recent experimental and analytical studies of the stress-strain behaviour of concrete confined by New Zealand manufactured Grade 275 or Grade 380 reinforcing steel are presented. First, the behaviour of three pairs of concentrically loaded reinforced concrete columns containing spirals from either Grade
275 or Grade 380 steel are compared, including the stage at which spiral fracture occurred. Second, the results of tests on four reinforced concrete columns containing Grade 380 spiral or rectangular hoop reinforcement and subjected to combined axial
load and cyclic lateral loading are reported. An analytical
study which was conducted to determine the available curvature ductility factor at the stage of fracture of the transverse reinforcement is described. The results are used to give a guideline for the safe use of Grade 380 steel as transverse confining reinforcement.

scholarly journals Behavior of Square RC Short Columns with New Arrangement of Ties Subjected to Axial Load: Experimental and Numerical Studies

2022 ◽  
Author(s):  
Hazem Elbakry ◽  
Tarek Ebeido ◽  
El-Tony M. El-Tony ◽  
Momen Ali
Keyword(s):  
Reinforced Concrete ◽  
Axial Load ◽  
Concrete Columns ◽  
Experimental Program ◽  
Transverse Reinforcement ◽  
Reinforcing Bars ◽  
Rc Columns ◽  
Reinforced Concrete Columns ◽  
Short Columns ◽  
Numerical Studies

Reinforced concrete columns consume large quantities of ties, especially inner cross-ties in columns with large dimensions. In some cases, nesting of the pillars occurs as a result of the presence of cross-ties. The main objective of this paper is to develop new methods for transverse reinforcement in RC columns and investigate their effect on the behavior of the columns. The proposed V-ties as transverse reinforcement replacing the ordinary and cross-ties details are economically feasible. They facilitate shorter construction periods and decrease materials and labor costs. For this purpose, experimental and numerical studies are carried out. In the experimental program, nine reinforced concrete columns with identical concrete dimensions and longitudinal reinforcing bars were prepared and tested under concentric axial load with different tie configurations. The main parameters were the tie configurations and the length (lv) of V-tie legs. As part of the numerical study, the finite element model using the ABAQUS software program obtained good agreement with the experimental results of specimens. A numerical parametric study was carried out to study the influence of concrete compressive strength and longitudinal reinforcement ratio on the behavior of RC columns with the considered tie configurations. Based on the experimental and numerical results, it was found that using V-tie techniques instead of traditional ties could increase the axial load capacity of columns, restrain early local buckling of the longitudinal reinforcing bars and improve the concrete core confinement of reinforced concrete columns.

scholarly journals Analytical Estimation of the Residual Drift of Reinforced Concrete Columns under the Ultimate Displacement Capacity

2020 ◽  
Author(s):  
Sinan Cansız
Keyword(s):  
Reinforced Concrete ◽  
Axial Load ◽  
Concrete Columns ◽  
Load Level ◽  
Transverse Reinforcement ◽  
Longitudinal Reinforcement ◽  
Reinforced Concrete Columns ◽  
Residual Drift ◽  
Drift Ratio ◽  
Ultimate Displacement

Reinforced concrete columns are the most important structural elements that determine the ductility of the structures. The main parameters affecting the behavior of reinforced concrete columns are axial load level, shear span, percent of longitudinal reinforcement and percent of transverse reinforcement. The aim of this study is to examine residual damage behavior of RC columns under cyclic loading similar to the earthquake loads combined depend on variable axial load level, spanning to depth ratio, longitudinal reinforcement ratio and transverse reinforcement ratio. When the results of experiments are examined, it can be seen that the residual drift ratio of reinforced concrete columns can be used to characterize the damage occurred in the structure after earthquake or loading. In addition, the performance level of the reinforced concrete columns according to the residual drift ratio is defined in FEMA356. As a result of this study, the analytical equation that calculates the residual drift ratio of the reinforced concrete columns at the ultimate displacement limit is proposed.

Drift Capacity of Reinforced Concrete Columns with Light Transverse Reinforcement

2005 ◽  
Vol 21 (1) ◽  
pp. 71-89 ◽  
Author(s):  
Kenneth J. Elwood ◽  
Jack P. Moehle
Keyword(s):  
Shear Strength ◽  
Reinforced Concrete ◽  
Shear Failure ◽  
Concrete Columns ◽  
Critical Parameters ◽  
Transverse Reinforcement ◽  
Reinforced Concrete Columns ◽  
Drift Capacity ◽  
Interstory Drift ◽  
Capacity Model

Existing reinforced concrete columns with light transverse reinforcement are vulnerable to shear failure during seismic response. Shear strength models, modeling the degradation of shear strength with increasing displacement ductility demand, have been widely used to evaluate the interstory drift capacity of such columns. The application of a shear strength model to determine the drift capacities for a database of 50 shear-critical columns demonstrates significant inaccuracies with such a method. An empirical drift capacity model based on the shear-critical column database provides a better estimate of the interstory drift at shear failure. The new drift capacity model identifies the most critical parameters affecting the drift capacity of shear-critical columns, namely, transverse reinforcement ratio, shear stress demand, and axial load ratio.

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