scholarly journals Effect of short glass fiber on shear capacity for shallow wide reinforced concrete beams

2021 ◽  
Vol 68 (1) ◽  
Author(s):  
Mohamed S. Moawad
Keyword(s):  
Shear Strength ◽  
Reinforced Concrete ◽  
Glass Fiber ◽  
Concrete Beams ◽  
Reinforced Concrete Beams ◽  
Experimental Program ◽  
Shear Stresses ◽  
Short Glass Fiber ◽  
Wide Beams ◽  
Short Glass

AbstractShallow wide reinforced concrete beams are used in modern buildings especially in residential building structures. According to current Egyptian Code Practice 203-2018; the characteristic of a shallow wide concrete beam is that the cross-section width (b) over the effective depth (d) ratio is greater than two and the beam depth is less than 250 mm. Without any shear reinforcing contribution, the applied shear stresses in shallow wide beams must be less than the concrete shear strength. And only concrete provides shear strength. An experimental program was conducted to investigate the contribution of short glass fiber polymer reinforcement to shear strength in shallow wide beams under shear stress. The short glass fiber polymer reinforcement ratio was the main parameter in this study. And also, the contribution of web shear stirrups reinforces against shear stresses. The experimental program consisted of five simply supported reinforced shallow wide concrete beams. Test results show that the use of short glass fiber reinforced polymer has a great effect on shear strength capacity, mode of failure, and ductility of shallow wide concrete beams.

scholarly journals Experimental analysis of steel fiber reinforced concrete beams in shear

2022 ◽  
Vol 15 (3) ◽  
Author(s):  
Aaron Kadima Lukanu Lwa Nzambi ◽  
Dênio Ramam Carvalho de Oliveira ◽  
Marcus Vinicius dos Santos Monteiro ◽  
Luiz Felipe Albuquerque da Silva
Keyword(s):  
Shear Strength ◽  
Reinforced Concrete ◽  
Steel Fiber ◽  
Concrete Beams ◽  
Reinforcement Ratio ◽  
Steel Fibers ◽  
Reinforced Concrete Beams ◽  
Experimental Program ◽  
Longitudinal Reinforcement ◽  
Fiber Addition

Abstract Some normative recommendations are conservative in relation to the shear strength of reinforced concrete beams, not directly considering the longitudinal reinforcement rate. An experimental program containing 8 beams of (100 x 250) mm2 and a length of 1,200 mm was carried out. The concrete compression strength was 20 MPa with and without 1.00% of steel fiber addition, without stirrups and varying the longitudinal reinforcement ratio. Comparisons between experimental failure loads and main design codes estimates were assessed. The results showed that the increase of the longitudinal reinforcement ratio from 0.87% to 2.14% in beams without steel fiber led to an improvement of 59% in shear strength caused by the dowel effect, while the corresponding improvement was of only 22% in fibered concrete beams. A maximum gain of 109% in shear strength was observed with the addition of 1% of steel fibers comparing beams with the same longitudinal reinforcement ratio (1.2%). A significant amount of shear strength was provided by the inclusion of the steel fibers and allowed controlling the propagation of cracks by the effect of stress transfer bridges, transforming the brittle shear mechanism into a ductile flexural one. From this, it is clear the shear benefit of the steel fiber addition when associated to the longitudinal reinforcement and optimal values for this relationship would improve results.

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.

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

scholarly journals Calibrating a New Constitutive Tension Model to Extract a Simplified Nonlinear Sectional Analysis of Reinforced Concrete Beams

2021 ◽  
Vol 11 (5) ◽  
pp. 2292
Author(s):  
Alaaeldin Abouelleil ◽  
Hayder A. Rasheed
Keyword(s):  
Reinforced Concrete ◽  
Concrete Beams ◽  
Compressive Strain ◽  
Design Criterion ◽  
Reinforced Concrete Beams ◽  
Secondary Outcome ◽  
Shear Stresses ◽  
Structural Members ◽  
Flexural Member ◽  
Smeared Crack

Nonlinear analysis of structural members is vital to understand the behavior and the response of reinforced concrete members. Even though most design procedures concentrate on the ultimate stage of response towards the end of the post-yielding zone as the decisive design criterion, the structural members usually function at the service load levels within the post-cracking zone. Therefore, cracking is a critical aspect of concrete behavior that affects the overall response of reinforced concrete beams. The initiation and the propagation of the cracks are affected directly by the tension and shear stresses in the beam. In flexural beams, the tensile stresses dominate the crack onset and its growth. Cracks in reinforced concrete flexural beams leave non-cracked regions in between the cracked sections. In order to apply a consistent analysis strategy, the smeared crack approach averages the behavior of these different cracked sections and uncracked in between regions to generate an accurate global response of the entire beam. This study presents a numerical constitutive tensile model that captures the complete tensile response of the reinforced concrete flexural member, in terms of averaged/smeared crack response. As a second step, this model was examined against a large pool of experimental data to validate its accuracy. Overall, the main objective of this study is to develop a representative constitutive tensile model for reinforced concrete flexural members and validate its accuracy against experimental results. The full nonlinear sectional response is analytically realized, based on the assumed trilinear moment–curvature response and the assumed trilinear moment–extreme fiber compressive strain response. This is considered as the secondary outcome of the present study.

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