Shear strength of members without transverse reinforcement

1996 ◽  
Vol 23 (1) ◽  
pp. 30-41 ◽  
Author(s):  
Perry Adebar ◽  
Michael P. Collins
Keyword(s):  
Shear Strength ◽  
Design Method ◽  
Bending Moment ◽  
American Concrete Institute ◽  
Shear Capacity ◽  
Transverse Reinforcement ◽  
Theory Approach ◽  
Shear Design ◽  
Truss Model ◽  
Variable Angle

The variable angle truss model is extended to members without transverse reinforcement by introducing concrete tension ties perpendicular to concrete compression struts. The modified compression field theory approach of limiting the shear transfer across diagonal cracks is combined with the variable angle truss model to develop equations for the shear capacity of members without transverse reinforcement. These equations are the theoretical basis of tabulated values for members without stirrups in the general shear design method of the 1994 Canadian concrete code. This paper also presents the results from an experimental study in which 27 narrow (beam-like) wall elements, with significant longitudinal reinforcement and little or no transverse reinforcement, were subjected to combined axial tension, bending moment, and shear. The experimental results are compared with predictions from the 1994 Canadian concrete code, as well as the American Concrete Institute building code. Key words: building codes, reinforced concrete, shear strength, structural design, tension, tests, truss model.

Background to the general method of shear design in the 1994 CSA-A23.3 standard

1999 ◽  
Vol 26 (6) ◽  
pp. 827-839 ◽  
Author(s):  
Khaldoun N Rahal ◽  
Michael P Collins
Keyword(s):  
Prestressed Concrete ◽  
Structural Design ◽  
Design Method ◽  
Bending Moment ◽  
Shear Capacity ◽  
Shear Design ◽  
Standard Design ◽  
Modified Compression Field Theory ◽  
Compression Field ◽  
General Method

The 1994 CSA-A23.3 standard "Design of concrete structures" includes a new shear design method based on the equations of the modified compression field theory (MCFT). This "general method" is a simplification which casts the MCFT in the traditional "Vc + Vs" format resulting in a set of six general equations and two tables. This new method unifies the treatment of reinforced, partially prestressed and fully prestressed concrete and accounts, in a rational manner, for the effects of axial load and bending moment on shear capacity. Simplifying the MCFT while maintaining acceptable generality and accuracy involved a number of considerations and assumptions. This paper gives the background to the development of these shear design equations and tables of the general method.Key words: beams, building codes, crack width and spacing, diagonal cracking, reinforced concrete, shear strength, size effect in shear, structural design.

scholarly journals Lateral shear strength of rectangular RC columns subjected to combined P-V-M monotonic loading

2020 ◽  
Vol 53 (4) ◽  
pp. 227-241
Author(s):  
Aysha M Zaneeb ◽  
Rupen Goswami ◽  
C V R Murty
Keyword(s):  
Shear Strength ◽  
Test Data ◽  
Rectangular Cross Section ◽  
Resistance Mechanism ◽  
Bending Moment ◽  
Shear Resistance ◽  
Shear Capacity ◽  
Longitudinal Reinforcement ◽  
Lateral Shear ◽  
Rc Columns

An analytical method is presented to estimate lateral shear strength (and identify likely mode and location of failure) in reinforced concrete (RC) cantilever columns of rectangular cross-section under combined axial force, shear force and bending moment. Change in shear capacity of concrete with flexural demand at a section is captured explicitly and the shear resistance offered by concrete estimated; this is combined with shear resistance offered by transverse and longitudinal reinforcement bars to estimate the overall shear capacity of RC columns. Shear–moment (V-M) interaction capacity diagram of an RC column, viewed alongside the demand diagram, identifies the lateral shear strength and failure mode. These analytical estimates compare well with test data of 107 RC columns published in literature; the test data corresponds to different axial loads, transverse reinforcement ratios, longitudinal reinforcement ratios, shear span to depth ratios, and loading conditions. Also, the analytical estimates are compared with those obtained using other analytical methods reported in literature; in all cases, the proposed method gives reasonable accuracy when estimating shear capacity of RC columns.  In addition, the method provides insights into the shear resistance mechanism in RC columns under the combined action of P-V-M, and it is simple to use.

THE ANALYSIS OF SHEAR STRENGTH OF FLEXURAL RC ELEMENTS ACCORDING TO EC2 AND STR / LENKIAMŲJŲ GELŽBETONINIŲ ELEMENTŲ ĮSTRIŽOJO PJŪVIO STIPRUMO PAGAL STR IR EC2 ANALIZĖ

2013 ◽  
Vol 4 (4) ◽  
pp. 133-144 ◽  
Author(s):  
Šarūnas Kelpša ◽  
Mindaugas Augonis
Keyword(s):  
Shear Strength ◽  
Reinforced Concrete ◽  
Cross Section ◽  
Shear Force ◽  
Bending Moment ◽  
Intersection Point ◽  
Shear Reinforcement ◽  
Truss Model ◽  
Calculation Results ◽  
The Difference

When the various reinforced concrete structures are designed according to EC2 and STR, the difference of calculation results, is quite significant. In this article the calculations of shear strength of bending reinforced concrete elements are investigated according to these standards. The comparison of such calculations is also significant in the sense that the shear strength calculations are carried out according to different principles. The STR regulations are based on work of the shear reinforcement crossing the oblique section and the compressed concrete at the end of the section. In this case, at the supporting zone, the external bending moment and shear force should be in equilibrium with the internal forces in reinforcement and compressed concrete, i.e., the cross section must be checked not only from the external shear force, but also from bending moment. In EC2 standard, the shear strengths are calculated according to simplified truss model, which consists of the tension shear reinforcement bars and compressed concrete struts. The bending moment is not estimated. After calculation analysis of these two methods the relationships between shear strength and various element parameters are presented. The elements reinforced with stirrups and bends are investigated additionally because in EC2 this case is not presented. According to EC2 the simplified truss model solution depends on the compression strut angle value θ, which is limited in certain interval. Since the component of tension reinforcement bar directly depends on the angle θ and the component of compression strut depends on it conversely, then exists some value θ when the both components are equal. So the angle θ can be found when such two components will be equated. However, such calculation of angle θ became complicated if the load is uniform, because then the components of tension bar are estimated not in support cross section but in cross section that are displaced by distance d. So, the cube equation should be solved. For simplification of such solution the graphical method to find out the angle θ and the shear strength are presented. In these graphics the intersection point of two components (shear reinforcement and concrete) curves describes the shear strength of element. Santrauka Straipsnyje apžvelgtos ir palygintos STR ir EC2 įstrižojo pjūvio stiprumo skaičiavimo metodikos stačiakampio skerspjūvio elementams. Normatyve neapibrėžtas EC2 metodikos santvaros modelio spyrių posvyrio kampo skaičiavimas, lemiantis galutinį įstrižojo pjūvio stiprumą. Straipsnyje pateikiamos kampo θ apskaičiavimo lygtys, atsižvelgiant į apkrovimo pobūdį. Norint supaprastinti pateiktų lygčių sprendimą siūlomas grafoanalitinis sprendimo būdas, pritaikant papildomus koeficientus. EC2 neapibrėžia skaičiavimo išraiškų, kai skersinis armavimas yra apkabos ir atlankos. Minėtos išraiškos suformuluotos ir pateiktos straipsnyje. Nustačius EC2 metodikos dėsningumus siūlomas alternatyvus apytikslis skaičiavimo būdas atlankomis ir apkabomis armuotiems elementams. Straipsnyje apžvelgtos abi – STR ir EC2 – metodikos, išskiriant pagrindinius skirtumus ir dėsningumus.

scholarly journals Shear Performance of Optimized-Section Precast Slab with Tapered Cross Section

2018 ◽  
Vol 11 (1) ◽  
pp. 163 ◽  
Author(s):  
Hyunjin Ju ◽  
Sun-Jin Han ◽  
Hyo-Eun Joo ◽  
Hae-Chang Cho ◽  
Kang Kim ◽  
...  
Keyword(s):  
Cross Section ◽  
Design Method ◽  
Precast Concrete ◽  
Bending Moment ◽  
Shear Behaviour ◽  
Element Analysis ◽  
Cross Sectional ◽  
Shear Design ◽  
Shear Performance ◽  
And Performance

The optimized-section precast slab (OPS) is a half precast concrete (PC) slab that highlights structural aesthetics while reducing the quantity of materials by means of an efficient cross-sectional configuration considering the distribution of a bending moment. However, since a tapered cross section where the locations of the top and bottom flanges change is formed at the end of the member, stress concentration occurs near the tapered cross section because of the shear force and thus the surrounding region of the tapered cross section may become unintentionally vulnerable. Therefore, in this study, experimental and numerical research was carried out to examine the shear behaviour characteristics and performance of the OPS with a tapered cross section. Shear tests were conducted on a total of eight OPS specimens, with the inclination angle of the tapered cross section, the presence of topping concrete and the amount of shear reinforcement as the main test variables and a reasonable shear-design method for the OPS members was proposed by means of a detailed analysis based on design code and finite-element analysis.

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 Concrete block structural masonry beam shear design: theoretical and experimental analysis and recommendations to the brazilian standards

2019 ◽  
Vol 12 (4) ◽  
pp. 884-909
Author(s):  
R. D. PASQUANTONIO ◽  
G. A. PARSEKIAN ◽  
J. S. CAMACHO
Keyword(s):  
Shear Strength ◽  
Literature Review ◽  
Experimental Tests ◽  
Concrete Block ◽  
Reinforced Concrete Beams ◽  
Experimental Program ◽  
Transverse Reinforcement ◽  
Extensive Literature ◽  
Shear Design ◽  
European Standards

Abstract Beams are subject a flexure and shear, with the last as the theme of this research. The purpose of this paper is to analyze specifications for the shear design of concrete block structural masonry beams, based on an extensive literature review and experimental tests here reported. From this scope, specifications for revision of Brazilian standardization are suggested. In the theoretical part, literature review from both national and international researchers were considered and the specifications of Brazilian standards, in addition to North American, Australian, Canadian and European, ABNT NBR 15961-1/2011, ABNT NBR 6118/2014TMS 402/2016, AS3700/2001, CSA S304/2014 and EuroCode6.1/2001, respectively. To analyze and validate the specifications of the literature, an experimental program was carried out assessing ten concrete block masonry beams results tested mainly to shear loads. Two-course high beams with three vertical load positions (position a/d) and two transverse reinforcement rates were tested. The specifications from the Brazilian and European standards led to considerably higher results than the experimental results, while those presented in the standards TMS 402/2016, AS3700/2001, CSA S304/2014 and NBR6118/2014 lead to results close to those obtained experimentally. As a conclusion, it can be noted that the rupture pattern is similar to that expected for reinforced concrete beams, the cracks were conditioned by the position of the loading point and by the mortar joints positions, the increase in the transverse reinforcement ratio led to an increase in the shear force. Results indicate that the consideration of apparent increase in shear strength by the ratio M ⁄ (V∙d) is not consistent. Eliminating this recommendation, considering the masonry shear strength equal to 0.35 MPa, limiting the stirrups tension to 0.90 of fyk and considering the contribution of the longitudinal reinforcement, it was possible to estimate the shear value at the rupture of each beam between 73% to 106% of the values verified in the tests.

Critical review of the CSA A23.3-94 punching shear strength provisions for interior columns

1996 ◽  
Vol 23 (5) ◽  
pp. 998-1011 ◽  
Author(s):  
Alaa G. Sherif ◽  
Walter H. Dilger
Keyword(s):  
Shear Strength ◽  
Critical Review ◽  
Shear Force ◽  
Bending Moment ◽  
Punching Shear ◽  
Design Codes ◽  
Shear Reinforcement ◽  
Model Code ◽  
Shear Design ◽  
Improved Design

The purpose of this paper is to demonstrate that the shear design of slabs according to the relevant Canadian CSA A23.3-94 (and U.S. ACI 318-95) design codes can be unsafe under certain conditions, and to propose improved design equations, some of which should be considered immediately for implementation in the Canadian CSA code. The paper deals with interior slab–column connections, with and without shear reinforcement, subjected to shear force alone or to a combination of shear force and unbalanced bending moment. Some comparisons with the British code BS 8110-85 and the CEB –FIP model code 1990 are also made. Tests reported in the literature and some experiments by the authors provide the basis for this study. Key words: flat concrete plates, slab–column connections, shear strength, punching shear, shear reinforcement, moment transfer.

scholarly journals Application of Artificial Intelligence Methods to Estimate Shear Strength of Reinforced Concrete Shear Wall

2020 ◽  
Author(s):  
Hosein Naderpour ◽  
Mohammadreza Sharei ◽  
Pouyan Fakharian
Keyword(s):  
Neural Network ◽  
Artificial Intelligence ◽  
Shear Strength ◽  
Reinforced Concrete ◽  
Shear Walls ◽  
Shear Wall ◽  
Shear Capacity ◽  
Reinforcement Ratio ◽  
Transverse Reinforcement ◽  
Vertical Reinforcement

Shear walls are the type of structural systems that provide the lateral resistance to a building or structure. Lateral loads are applied on one plate and along the vertical dimension of the wall. These type of loads are usually transmitted to the wall collectors. Concrete shear walls have a considerable resistance to lateral seismic loading. Model prediction is required for the shear capacity of these walls to ensure the seismic security of the building. Therefore, a model is proposed to estimate the shear strength of concrete walls using an artificial intelligence algorithm. The input parameters of the neural network include the thickness of the reinforced concrete shear wall, the wall length, the vertical reinforcement ratio, the transverse reinforcement ratio, the compressive strength of the concrete, the stresses of the transverse reinforcement, the stresses of the vertical reinforcement, the ratio of the dimensions. The target parameter is the shear strength of the reinforced concrete shear wall. A total of 58 laboratory data was collected on concrete shear walls. The results of the research show that optimum artificial neural network with a specific number of hidden neurons can accurately estimate the shear capacity of reinforced concrete shear walls. The results indicate that the highest percentage of effect and the lowest percentage of effect have a target function. Additionally, the error rate obtained for predicting shear capacity is 7%, which is an acceptable error in this regard.

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