Predicting the effect of stirrups on shear strength of reinforced normal-strength concrete (NSC) and high-strength concrete (HSC) slender beams using artificial intelligence

2006 ◽  
Vol 33 (8) ◽  
pp. 933-944 ◽  
Author(s):  
H El Chabib ◽  
M Nehdi ◽  
A Saïd
Keyword(s):  
Shear Strength ◽  
Reinforced Concrete ◽  
High Strength ◽  
Shear Capacity ◽  
Reinforced Concrete Beams ◽  
Design Parameters ◽  
Rc Beams ◽  
Shear Reinforcement ◽  
Strength Concrete ◽  
Shear Design

The exact effect that each of the basic shear design parameters exerts on the shear capacity of reinforced concrete (RC) beams without shear reinforcement (Vc) is still unclear. Previous research on this subject often yielded contradictory results, especially for reinforced high-strength concrete (HSC) beams. Furthermore, by simply adding Vc and the contribution of stirrups Vs to calculate the ultimate shear capacity Vu, current shear design practice assumes that the addition of stirrups does not alter the effect of shear design parameters on Vc. This paper investigates the validity of such a practice. Data on 656 reinforced concrete beams were used to train an artificial neural network model to predict the shear capacity of reinforced concrete beams and evaluate the performance of several existing shear strength calculation procedures. A parametric study revealed that the effect of shear reinforcement on the shear strength of RC beams decreases at a higher reinforcement ratio. It was also observed that the concrete contribution to shear resistance, Vc, in RC beams with shear reinforcement is noticeably larger than that in beams without shear reinforcement, and therefore most current shear design procedures provide conservative predictions for the shear strength of RC beams with shear reinforcement.Key words: analysis, artificial intelligence, beam depth, compressive strength, modeling, shear span, shear strength.

scholarly journals Influence of coarse aggregate on the shear strength of reinforced concrete beams

2020 ◽  
Author(s):  
◽  
Hoosen Ahmed Jajbhay
Keyword(s):  
Shear Strength ◽  
Reinforced Concrete ◽  
Concrete Beam ◽  
Coarse Aggregate ◽  
Concrete Beams ◽  
Shear Capacity ◽  
Reinforced Concrete Beams ◽  
Shear Reinforcement ◽  
Shear Transfer ◽  
Coarse Aggregates

Research to accurately predict the shear capacity of reinforced concrete beams without shear reinforcement has been ongoing since the early 20th century. Aggregate interlock of the coarse aggregates at the shear crack interface is one of the internal mechanisms of shear transfer and a major contributor to the shear capacity of slender beams. It is plausible, therefore, to investigate if the coarse aggregate itself influences the shear capacity of a concrete beam. The influence of the type of coarse aggregate on the shear capacity of beams without shear reinforcement was investigated in this study. From the literature study an understanding of the properties of coarse aggregates was gained, the internal mechanisms of shear transfer in reinforced concrete beams without shear reinforcement were determined, and the parameters influencing shear strength were identified. Based on this information an experimental program was designed. Eighteen reinforced concrete beams without shear reinforcement were cast. The beams were cast from three different types of coarse aggregates commonly used in the Durban area, i.e., dolerite, quartzite and tillite. For each type of coarse aggregate two variations were tested, i.e., 13 mm and 19 mm maximum aggregate sizes. For each size of coarse aggregate, three concrete strengths were tested. The beams were loaded in a beam press, by applying an increasing point load offset from midspan to induce cracking on the shorter side, until shear failure of the beam occurred. For the three concrete strengths, beams cast from dolerite had the highest shear capacity while beams cast from tillite had less shear capacity than beams cast from quartzite coarse aggregate. Furthermore, beams cast from 13 mm maximum size coarse aggregate had higher shear capacity than beams cast from 19 mm aggregate. The conclusion may be drawn that the type and size of coarse aggregate does influence the shear strength of a reinforced concrete beam without shear 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.

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.

Shear design off high strength concrete beams — Canadian code perspective

1996 ◽  
Vol 23 (4) ◽  
pp. 809-819 ◽  
Author(s):  
Maria Anna Polak ◽  
Jaroslaw J. Dubas
Keyword(s):  
Compressive Strength ◽  
Shear Strength ◽  
High Strength Concrete ◽  
Concrete Beams ◽  
High Strength ◽  
Shear Behaviour ◽  
Shear Reinforcement ◽  
Concrete Compressive Strength ◽  
Strength Concrete ◽  
Shear Design

The paper presents the results of an investigation of the influence of concrete compressive strength on the shear strength of reinforced concrete beams, both nonprestressed and prestressed. A total of 132 existing tests on high strength concrete beams, with and without shear reinforcement, were analyzed and compared with the shear design provisions of the CSA Standard CAN3-A23.3-M94 and the previous version of the code, CAN3-A23.3-M84. The main parameter in the investigation was the concrete compressive strength. Owing to the complex nature of shear behaviour and the interdependence of the factors affecting shear strength, other parameters such as the shear span to depth ratio, the longitudinal reinforcement ratio, and the amount of shear reinforcement were varied, as well as the concrete strength. Key words: shear, beams, high strength concrete, code methods, shear reinforcement index, shear ratio, predictions, strength.

scholarly journals An experimental study on the shear capacity of corroded reinforced concrete beams without shear reinforcement

2021 ◽  
Vol 15 (1) ◽  
pp. 55-66
Author(s):  
Nguyen Ngoc Tan ◽  
Nguyen Trung Kien
Keyword(s):  
Shear Strength ◽  
Reinforced Concrete ◽  
Concrete Beam ◽  
Reinforced Concrete Beam ◽  
Shear Capacity ◽  
Reinforced Concrete Beams ◽  
Rc Beams ◽  
Accelerated Corrosion ◽  
Steel Rebar ◽  
Accelerated Corrosion Test

The effect of corrosion on the structural behavior of reinforced concrete (RC) beams without stirrups was experimentally investigated. A total of eight medium-scale RC beams were constructed without stirrups. The beams were 150 mm in width, 200 mm in depth, and 1100 mm in length. Test variables included three distinct degrees of corrosion (0%, 3.13%, 4.11%, and 4.93% by mass loss of steel rebar). Six beams were subjected to an accelerated corrosion test, while two beams served as non-corroded control beams. All beams were tested under four-point loading failure after the corrosion stage. The effect of various small degrees of corroded longitudinal reinforcements has been observed for the shear capacity. Test findings found that all tested beams had a brittle failure with tested corrosion degrees. Moreover, corroded beams that are exposed to 3% and 4% average corrosion degree reported having a larger shear capacity of approximately 7% compared to control beams. Lastly, beams with a corrosion degree of about 5% showed a decrease of 10% shear strength and a different failure mechanism with distinguished cracking patterns due to the formation of corrosion cracks along the longitudinal reinforcements. Keywords: reinforced concrete beam; reinforcement corrosion; shear strength; no stirrups.

scholarly journals Influence of Shear Span-to-Effective Depth Ratio on Behavior of High-Strength Reinforced Concrete Beams

2021 ◽  
Vol 15 (1) ◽  
Author(s):  
Olaniyi Arowojolu ◽  
Ahmed Ibrahim ◽  
Abdullah Almakrab ◽  
Nicholas Saras ◽  
Richard Nielsen
Keyword(s):  
Shear Strength ◽  
Reinforced Concrete ◽  
High Strength ◽  
Shear Resistance ◽  
Design Guidelines ◽  
Reinforced Concrete Beams ◽  
Shear Reinforcement ◽  
Shear Span ◽  
Depth Ratio ◽  
Effective Depth

AbstractThe shear span-to-effective depth ratio (a/d) is one of the factors governing the shear behavior of reinforced concrete (RC) beams, with or without shear reinforcement. In high-strength concrete (HSC), cracks may propagate between the aggregate particles and result in a brittle failure which is against the philosophy of most design guidelines. The experimental results of six HSC beams, with and without shear reinforcement, tested under four-point bending with a/d ranged from 2.0 to 3.0 are presented and compared with different model equations in design codes. The a/d ratio has higher influence on the shear strength of reinforced HSC beams without shear reinforcement than beams with shear reinforcement. Most of the shear resistance prediction models underestimate the concrete shear strength of the beams but overpredict shear resistance of beams with shear reinforcement. However, the fib Model code 2010 accurately predicted the shear resistance for all the beams within an appropriate level of approximation (LoA).

scholarly journals SHEAR STRENGTH OF RC BEAMS WITHOUT STIRRUP USING HIGH-STRENGTH CONCRETE OF COMPRESSIVE STRENGTH RANGING TO 130MPa

2003 ◽  
pp. 75-91
Author(s):  
Motoyuki SUZUKI ◽  
Mitsuyoshi AKIYAMA ◽  
Wei Lun WANG ◽  
Masayoshi SATO ◽  
Naomi MAEDA ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Shear Strength ◽  
High Strength Concrete ◽  
High Strength ◽  
Rc Beams ◽  
Strength Concrete
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