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 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

Shear Strength of Normal and High Strength Concrete Beams Reinforced with GFRP Bars

2003 ◽  
Author(s):  
Shawn P. Gross ◽  
Joseph Robert Yost ◽  
David W. Dinehart ◽  
Erik Svensen ◽  
Ning Liu
Keyword(s):  
Shear Strength ◽  
High Strength Concrete ◽  
Concrete Beams ◽  
High Strength ◽  
Strength Concrete ◽  
Gfrp Bars

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.

Sensitivity of shear strength to fracture energy of high-strength concrete slabs

1998 ◽  
Vol 25 (1) ◽  
pp. 40-50 ◽  
Author(s):  
H Marzouk ◽  
M Emam ◽  
M S Hilal
Keyword(s):  
Compressive Strength ◽  
Shear Strength ◽  
High Strength Concrete ◽  
Shear Failure ◽  
High Strength ◽  
Tensile Fracture ◽  
Concrete Slabs ◽  
Square Root ◽  
Fracture Properties ◽  
Strength Concrete

The test results of an earlier experimental investigation conducted at Memorial University of Newfoundland on high-strength concrete slabs indicated that as the concrete slab strength increased from 35 to 75 MPa the shear strength increased by 7-20%, depending on the case of loading, i.e., concentric or eccentric loads. The increasing ratio of shear strength is less than half that prescribed in the Canadian code CSA-A23.3 (1994) or the ACI-318 code (1995). Hence, the significant difference between the experimental results and the predicted strength by existing North American codes tacitly means that the proportionality between the shear strength and the square root of the compressive strength is not accurate enough to predict the shear strength of high-strength concrete slabs. In the present investigation, a fracture mechanics model suitable for concrete was proposed. It was also suggested that this model might be an advantageous aid in the analysis of the shear failure of reinforced concrete slabs. In this research investigation the fracture mechanics approach utilizing finite element aided computer analysis of several reinforced slabs is briefly described, and calculated shear failure loads are given. The recommended model proves that it is necessary to consider not only the tensile strength of concrete, instead of the square root of the compressive strength, but also the tensile fracture properties of high-strength concrete. The tensile fracture properties of concrete are characterized by the parameter called characteristic length and the brittleness of concrete. The brittleness ratio of concrete slabs must be considered in any rational shear design expression to reflect the size effect factor and the aggregate type.Key words: fracture energy, uniaxial direct tension, shear strength, high-strength concrete, punching shear, slab, size effect, finite element analysis.

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