A Study on the Safety of Shear design of Reinforced Concrete Beams

2004 ◽  
Vol 20 (4) ◽  
pp. 303-309 ◽  
Author(s):  
W. Y. Lu ◽  
I. J. Lin
Keyword(s):  
Shear Strength ◽  
Reinforced Concrete ◽  
North America ◽  
Shear Failure ◽  
Statistical Data ◽  
Concrete Beams ◽  
Reinforced Concrete Beams ◽  
Theoretical Shear Strength ◽  
Shear Design ◽  
Failure Probabilities

AbstractThe shear failure probabilities of reinforced concrete beams have been investigated by Monte Carlo technique. The shear strength provided by the concrete is based on the theoretical model developed by Tureyen and Frosch (2003). The random variables included in this study are the strength of concrete, the strength of reinforcing steel, the dimension of cross-section, the model error of theoretical shear strength provided by the concrete, and the loading. This study shows that based on the new material statistical data (2003) in North America, the shear failure probabilities are acceptable for beams designed using the ACI 318-02 Code. Based on the old material statistical data (1979) in North America the shear failure probabilities of beams designed using the ACI Code are relatively high. For the safety of shear design of reinforced concrete beams, the ACI 318-02 Code is better than the ACI 318-99 Code.

Does the shear strength of reinforced concrete beams and slabs depend upon the flexural reinforcement ratio or the reinforcement strain?

2013 ◽  
Vol 40 (11) ◽  
pp. 1068-1081 ◽  
Author(s):  
Mitra Noghreh Khaja ◽  
Edward G. Sherwood
Keyword(s):  
Shear Strength ◽  
Reinforced Concrete ◽  
Concrete Beams ◽  
Reinforcement Ratio ◽  
Reinforced Concrete Beams ◽  
Shear Stresses ◽  
Shear Design ◽  
Reinforced Polymer ◽  
Fibre Reinforced Polymer ◽  
General Method

Beam tests are conducted to investigate the effect of the reinforcement ratio, ρ, and the shear span to depth ratio, a/d, on the shear strength of reinforced concrete beams and slabs without stirrups. The a/d ratio is shown to have a very significant effect on shear strength at both low values of a/d (where failure is governed by strut-and-tie mechanisms) and large values of a/d (where failure is governed by breakdown in beam action). Increases in ρ associated with increases in a/d such that the strain, or M/ρVd ratio, is kept constant will result in constant failure shear stresses. Shear design methods that do not account for a/d (e.g., ACI Committee 440) cannot predict the observed experimental behaviour, whereas the general method of the CSA A23.3 code can. Using the ACI 440 equation for Vc may reduce the economic competitiveness of fibre-reinforced polymer reinforcement versus steel reinforcement.

Implication of Unbondedness in Reinforced Concrete Beams

2012 ◽  
Vol 587 ◽  
pp. 36-41 ◽  
Author(s):  
S.F.A. Rafeeqi ◽  
S.U. Khan ◽  
N.S. Zafar ◽  
T. Ayub
Keyword(s):  
Shear Strength ◽  
Reinforced Concrete ◽  
Failure Mode ◽  
Shear Failure ◽  
Concrete Beams ◽  
Experimental Results ◽  
Reinforced Concrete Beams ◽  
Rc Beams ◽  
Flexural Capacity ◽  
Flexural Reinforcement

In this paper, behaviour of nine (09) RC beams (including two control beams) after unbonding and exposing flexural reinforcement has been studied which were intentionally designed and detailed to observe flexural and shear failure. Beams have been divided into three groups based on failure mode and unbounded and exposed reinforcement. Beams have been tested under two-point loading up to failure. Experimental results are compared in terms of beam behaviour with respect to flexural capacity and failure mode which revealed that the exposed reinforcement does not altered flexural capacity significantly and unbondedness positively influences shear strength; however, serviceability performance of beams with unbonded and exposed reinforcement is less.

A Study on the Safety of the Shear Capacity Design of Reinforced Concrete Beam-Column Joints

2006 ◽  
Vol 22 (4) ◽  
pp. 311-320 ◽  
Author(s):  
W.-Y. Lu
Keyword(s):  
Shear Strength ◽  
Reinforced Concrete ◽  
Concrete Beam ◽  
Shear Failure ◽  
Reinforced Concrete Beam ◽  
Theoretical Shear Strength ◽  
Strut And Tie ◽  
Flexural Reinforcement ◽  
Strut And Tie Model ◽  
Failure Probabilities

AbstractThe shear failure probabilities of reinforced concrete beam-column joints have been investigated by Monte Carlo method. The theoretical shear strength of joints is based on the softened strut-and-tie model proposed by Hwang and Lee (2002). The random variables included in this study are the strengths of concrete, the ultimate compression strain of concrete, the strengths of reinforcement, the dimensions of cross-section, and the model error of theoretical shear strength of joints. The shear failure probabilities of joints with SD 280 flexural reinforcement in the beams designed using the ACI Code are all higher than 0.04. The joints designed according to the softened strut-and-tie model are safer than those designed according to the ACI Code. The shear failure probabilities of exterior joints are higher than those of interior joints. The shear failure probabilities of joints with SD 280 flexural reinforcement in the beams are higher than those of joints with SD 420 flexural reinforcement.

scholarly journals Modelling of Shear Strength for Reinforced Concrete Beams Provided with Side-Face Reinforcement in Dependence of Crack Inclination Angle

2019 ◽  
Vol 8 (6) ◽  
pp. 3941-3950
Keyword(s):  
Shear Strength ◽  
Reinforced Concrete ◽  
Inclination Angle ◽  
Concrete Beams ◽  
Concrete Strength ◽  
Reinforced Concrete Beams ◽  
Rc Beams ◽  
Shear Design ◽  
Web Reinforcement ◽  
Side Face

Shear behavior of reinforced concrete beams (RCbeams) is proved to be influenced by different parameters such as web reinforcement, beam size, shear span-to-depth ratio, concrete strength, and longitudinal reinforcement. In addition to these parameters, researches acknowledge the significant contribution of side-face reinforcement (SFR) in shear strength of RC-beams. This paper aims at proposing a new model for predicting shear strength of RC-beams that accounts for the contribution of SFR in shear strength along with the other above-mentioned parameters. An explicit formula is derived based on a mechanical conceptual model that considers the variation of the inclination angle of diagonal shear cracking. The derived formula is verified on the basis of numerical analysis results in addition to the available results from relevant experimental researches in literature. Reliability of the proposed formula is investigated compared to design provisions in different codes. Results demonstrates that the proposed formula is more capable of predicting shear strength of RC-beams provided with SFR rather than shear design codes. Consistency of the proposed formula in predicting shear strength implies that the mechanical concept, on which the proposed formula is derived, is in consistent with the actual mechanical behavior.

Reinforced concrete beams without stirrups considering shear friction and fracture mechanics

2006 ◽  
Vol 33 (2) ◽  
pp. 161-168 ◽  
Author(s):  
M T Kazemi ◽  
V Broujerdian
Keyword(s):  
Shear Strength ◽  
Reinforced Concrete ◽  
Fracture Mechanics ◽  
Shear Failure ◽  
Concrete Beams ◽  
Concrete Strength ◽  
Shear Capacity ◽  
Reinforced Concrete Beams ◽  
Maximum Aggregate Size ◽  
Aggregate Interlock

A new expression for the shear capacity of reinforced concrete beams without stirrups was derived by calculating the aggregate interlock capacity across the major diagonal crack of the beam, a procedure somewhat similar to those based on the modified compression field theory. Two formulas were obtained from the simplification of this expression. All three relations capture the dependence of shear strength on the size of the beam, the ratio of shear span to beam depth, longitudinal reinforcement ratio, maximum aggregate size, and concrete strength. The limits of these formulas agree well with the limit solutions of shear failure load for very small and very large beams based on plastic and fracture mechanics solutions, respectively. The proposed relations were calibrated by least-squares fitting of the existing experimental database (consisting of 398 data points) and resulted in low coefficients of variation. The simplest version is suitable for design codes.Key words: reinforced concrete, shear strength, beams, aggregate interlock, crack opening, size effect.

scholarly journals Influence of Steel Fiber on the Shear Strength of a Concrete Beam

2018 ◽  
Vol 4 (7) ◽  
pp. 1501 ◽  
Author(s):  
Ali Ammar Hameed ◽  
Mohannad Husain Al-Sherrawi
Keyword(s):  
Shear Strength ◽  
Reinforced Concrete ◽  
Concrete Beam ◽  
Shear Failure ◽  
Steel Fiber ◽  
Concrete Beams ◽  
Shear Capacity ◽  
Steel Fibers ◽  
Reinforced Concrete Beams ◽  
Shear Reinforcement

The shear failure in a concrete beam is a brittle type of failure. The addition of steel fibers in a plain concrete mix helps to bridge and restrict the cracks formed in the brittle concrete under applied loads, and enhances the ductility of the concrete. In this research an attempt was made to investigate the behavior and the ultimate shear strength of hooked end steel fiber reinforced concrete beams without traditional shear reinforcement. Four simply-supported reinforced concrete beams with a shear span-to-depth ratio of about 3.0 were tested under two-point loading up to failure. Steel fibers volumetric fractions that used were 0.0, 0.5, 0.75 and 1.0%. Test results indicated that using 1.0% volume fraction of hooked steel fiber led to exclude shear failure and enhanced the use of steel fibers as shear reinforcement in concrete beams. The results also showed that a concrete beam with hooked steel fiber provided higher post-flexural-cracking stiffness, an increase in the shear capacity and energy absorption and an increase in the maximum concrete and steel reinforcement strains.

scholarly journals A Model for Shear Strength of FRP Bar Reinforced Concrete Beams without Stirrups

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Danying Gao ◽  
Changhui Zhang
Keyword(s):  
Shear Strength ◽  
Reinforced Concrete ◽  
Shear Failure ◽  
Concrete Beams ◽  
Reinforced Concrete Beam ◽  
Reinforced Concrete Beams ◽  
Experimental Database ◽  
Proposed Model ◽  
Frp Bar ◽  
Set Up

The shear failure of a reinforced concrete beam generally occurs when the principal tensile stress near the neutral axis is equal to or greater than the tension strength of concrete. In order to set up a model for shear strength for FRP bar reinforced concrete beams without stirrups by the mechanical method, this paper equivalently transformed the FRP bar reinforced concrete rectangular beam with cracks as one composed of ideal elastic material to facilitate the analysis and proposed a new and more reasonable model of shear strength for FRP bar reinforced concrete beams without stirrups. Then, an experimental database including 235 FRP bar reinforced beams without stirrups was compiled to verify the validity of the proposed model. It was found that the values from the proposed model are in better agreement with the experimental results of shear strength of FRP bar reinforced concrete beams without stirrups in comparison with the models in codes.

Evaluation of Shear Strength of Concrete Beams with GFRP Reinforcement

2014 ◽  
Vol 660 ◽  
pp. 603-612 ◽  
Author(s):  
Imohamed Ali ◽  
Abdul Aziz Abdul Samad ◽  
Noridah Mohamad ◽  
Ghusen Al-Kafri ◽  
Ahamad Mohmmed
Keyword(s):  
Shear Strength ◽  
Shear Failure ◽  
Concrete Beams ◽  
Concrete Strength ◽  
Reinforced Concrete Beams ◽  
Longitudinal Reinforcement ◽  
Gfrp Bars ◽  
Shear Design ◽  
Glass Fiber Reinforced ◽  
Diagonal Crack

This research presents an experimental study related to the shear behavior of simply supported reinforced concrete beams reinforced with Glass Fiber Reinforced Polymer (GFRP) bars. Four concrete beams reinforced with GFRP bars and four control concrete beams reinforced with steel bars were tested until failure. In order to realize the occurrence of shear failure, all tested beams were designed with longitudinal reinforcement only and without shear reinforcement. The test variables used in this study were the concrete strength, f'c, and longitudinal reinforcement ratio, ρ. The crack patterns, location of the diagonal crack and angle of the diagonal crack were also observed during the test. The shear design equations obtained from the codes and references were used to evaluate the data obtained from the test. Finally, based on the data obtained from experimental and theoretical analysis, comments and recommendation on the shear strength equations were suggested.

Shear strength of reinforced concrete beams with T-headed bars for safety-related nuclear structures

2021 ◽  
Vol 230 ◽  
pp. 111705
Author(s):  
Yuxing Yang ◽  
Amit H. Varma ◽  
Michael E. Kreger ◽  
Ying Wang ◽  
Kai Zhang
Keyword(s):  
Shear Strength ◽  
Reinforced Concrete ◽  
Concrete Beams ◽  
Reinforced Concrete Beams ◽  
Nuclear Structures
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