Shear resistance of GFRP-reinforced concrete beams

2011 ◽  
Vol 63 (3) ◽  
pp. 215-233 ◽  
Author(s):  
Long Nguyen-Minh ◽  
Marián Rovňák
Keyword(s):  
Reinforced Concrete ◽  
Concrete Beams ◽  
Shear Resistance ◽  
Reinforced Concrete Beams

scholarly journals Shear resistance of welded inclined bars in rectangular reinforced concrete beams

2018 ◽  
Vol 250 ◽  
pp. 03003
Author(s):  
Noor Suhaida Galip ◽  
Roslli Noor Mohamed ◽  
Ramli Abdullah
Keyword(s):  
Reinforced Concrete ◽  
Failure Modes ◽  
Concrete Beams ◽  
Shear Resistance ◽  
Reinforced Concrete Beams ◽  
Shear Reinforcement ◽  
Shear Forces ◽  
Distance Ratio ◽  
Effective System ◽  
Horizontal Portion

The bent-up bars have not been used as shear reinforcement in beams since the past 40 years or so. In all cases of design and construction nowadays, shear forces are resisted by vertical links only. Some complications in installing the multiple set of bent-up bars, the less opportunity to have sufficient number of bent-up bars due to small number of flexural reinforcement provided at the mid-span of the beams and also the large anchorage required for the horizontal portion of the bars beyond the upper end of the bend could be the reasons behind this. This paper presents the results of tests on five rectangular reinforced concrete beams in which the effectiveness of welded inclined bars (WIB) as shear reinforcement was studied. Two of the beams were controlled specimens, with no shear reinforcement in one, and full design vertical links in another. The other three beams were provided with three different quantities of WIB, measured in terms of area to distance ratio, Asw / S as shear reinforcement in the shear spans. All beams were tested to failure under two point loads with a shear span to effective depth ratio of 2.34, which would ensure that the failure was due to shear unless their shear capacities were larger than the flexural capacity. The performances of the beams were measured in terms of deflection, crack formation, strains in WIB and on the concrete surfaces in the shear region, ultimate loads and failure modes. The results show that WIB alone is capable of carrying the whole shear forces in the beam, and larger shear capacities are achieved with a larger quantity of WIB, and a higher grade of the bars used. The beam with WIB requires 22% less in the quantity of Asw / S compared to that with vertical links to achieve the same shear resistance. These suggest that WIB can be used as an effective system of shear reinforcement in beams.

scholarly journals Shear Performance of Steel Fibers in Reinforced Concrete Beams

2019 ◽  
Vol 9 (2) ◽  
pp. 345-350
Keyword(s):  
Reinforced Concrete ◽  
Concrete Beams ◽  
Resistance Mechanism ◽  
Shear Resistance ◽  
Fiber Reinforced Concrete ◽  
Steel Fibers ◽  
Reinforced Concrete Beams ◽  
Experimental Program ◽  
Shear Reinforcement ◽  
Shear Span

Over the past few decades, a significant growth was observed on utilization of steel fibers in Reinforced Concrete (R.C) members. Past research studies on hybrid concrete endorsed optimum utilization of steel fibers (1.5% by volume) as it effectively contributed to improve flexural properties of reinforced concrete members such as R.C beams and slabs .But the contribution of fibers against shear resistance mechanism of R.C beams are not identified well in the previous research. In this context an experimental program was conducted to find Shear contribution and associated Parameters of fibers in the Steel Fiber Reinforced Concrete (SFRC) beams. A series of test programmes are conducted on three full scale reinforced concrete beams (NSF: No steel fibers, BSF1: Steel fibers in shear span, BSF2: Steel fibers in full span) with different configuration of shear reinforcement by using varied range of SFRC in the tested beam. The test results evaluated on the basis of strength and durability aspects at service loads and limit of failure conditions. The results concluded that the presence of steel fibers in reinforced concrete beam significantly contributed to induce shear resistance mechanism and ductile property of R.C beam. This improvement observed in BSF2, when the SFRC constituted in shear span region and the rest of R.C beam arranged with minimum conventional stirrups as shear reinforcement. Further the steel fibers possess good compatibility with concrete and steel reinforcement ,which enhance mechanical and serviceability conditions of R.C beam such as shear strength, ductility, stiffness with respect to strength and deflection, crack width during serviceability conditions of the beam.

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