Effect of polypropylene and steel fibers on web-shear resistance of deep concrete hollow-core slabs

2020 ◽  
Vol 210 ◽  
pp. 110273
Author(s):  
Hang T.N. Nguyen ◽  
Kang Hai Tan ◽  
Tetsushi Kanda
Keyword(s):  
Shear Resistance ◽  
Steel Fibers ◽  
Hollow Core

scholarly journals Fibrous Reinforcing System to Increase the Shear Resistance of High Strength Concrete

2008 ◽  
Vol 587-588 ◽  
pp. 887-891
Author(s):  
Simão Santos ◽  
Joaquim Barros ◽  
Lúcio Lourenço
Keyword(s):  
High Strength Concrete ◽  
High Strength ◽  
Shear Resistance ◽  
Shear Loading ◽  
Fiber Reinforced Concrete ◽  
Steel Fibers ◽  
Experimental Program ◽  
Compression Tests ◽  
Strength Concrete ◽  
High Strength Fiber

The available research has evidenced that discrete steel fibers can increase significantly the shear resistance of High Strength Concrete (HSC) structural elements when High Strength Fiber Reinforced Concrete (HSFRC) is designed in such way that fiber reinforcing mechanisms are optimized. In general, the increase of the concrete compressive strength is associated to an increase of its compactness, resulting benefits in terms of durability, but a strong concern emerges related to the integrity of this material, since it fails in a too brittle mode when submitted to high temperatures. To contribute for the knowledge about the benefits provided by discrete steel fibers when added to HSC applied to laminar structures, an experimental program composed of slab strips submitted to shear loading configuration was carried out. Uniaxial compression tests with cylinders of 150 mm diameter and 300 mm height, and bending tests with 600×150×150 mm3 beams were executed to assess the compression and bending behavior of the developed HSFRC. To evaluate the influence of the percentage of fibers in the shear resistance of laminar structures, three point loading tests with slab strips of 800×170×150 mm3 dimensions were performed. Taking the obtained experimental results, the applicability of the formulation proposed by RILEM TC 162-TDF was evaluated. Test results showed that, even with relative low dosages of steel fibers, the increment in shear resistance was significantly increased. The main obtained results in the research program are presented and discussed in this paper.

scholarly journals Effect of fiber amount and stirrup ratio on shear resistance of steel fiber reinforced concrete deep beams

2021 ◽  
Vol 15 (2) ◽  
pp. 1-13
Author(s):  
Thang Do-Dai ◽  
Duong T. Tran ◽  
Long Nguyen-Minh
Keyword(s):  
Reinforced Concrete ◽  
Steel Fiber ◽  
Shear Crack ◽  
Shear Resistance ◽  
Shear Capacity ◽  
Fiber Reinforced Concrete ◽  
Steel Fibers ◽  
Experimental Program ◽  
Deep Beam ◽  
Deep Beams

This paper deals with the effect of steel fiber amounts and the interaction between the fiber amount and stirrup ratio on the shear behavior and capacity of reinforced concrete (RC) deep beams with steel fibers. The experimental program was carried out on twelve deep beams with different fiber amounts (0, 30, 40, and 65 kg/m3) and stirrup ratios (0.1, 0.15, and 0.25%). The test results have shown that the use of steel fibers increased the shear resistance (up to 55%), reduced the shear crack width (up to 11 times) and deflection (up to 57%) of the tested deep beams. Also, it was found that using unsuitable steel fiber amount and stirrup ratio would reduce the efficiency of the fibers in a deep beam due to the interaction between the fibers and stirrups. Increasing the stirrup ratio in a deep beam with a high amount of steel fibers can reduce the efficacy of the fibers in enhancing the shear capacity of the beam. The most cost-effective steel fiber amount was found to be around 30 to 45 kg/m3. Keywords: steel fibers; deep beam; shear capacity; fiber amount; stirrup ratio.

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.

scholarly journals Analytical model for determining the influence of support flexibility on shear capacity of hollow core slabs

2019 ◽  
Vol 262 ◽  
pp. 08005 ◽  
Author(s):  
Mateusz Surma ◽  
Wit Derkowski ◽  
Andrzej Cholewicki
Keyword(s):  
Prestressed Concrete ◽  
Model Development ◽  
Simple Calculation ◽  
Shear Resistance ◽  
Shear Capacity ◽  
Beam Model ◽  
Hollow Core ◽  
Engineering Analysis ◽  
Flexible Supports ◽  
German Model

The paper presents the authors’ model of calculating the shear capacity of prestressed concrete hollow core slabs in Slim Floor structures, the theoretical basis of which is Cholewicki’s two-beam model and the Finnish model by Pajari and Leskelӓ. The purpose of the model development was to find an alternative method for determining the horizontal tangential stress τzx which occurrence is decisive for reducing the shear resistance of channel slabs based on flexible supports. The model gives intermediate results between the Finnish model and the German model by Hegger and Roggendorf, which seems to be desirable, taking into account the conservative character of the Finnish model. The authors’ model is the first attempt to date at analytical consideration of the effect of web flexibility which may be important to maintaining an adequate capacity of the slab. In other models, the webs are treated as a rigid system, connecting the horizontal flanges of the slab. The model is a simple calculation tool, available to Slim Floor designers for an engineering analysis.

scholarly journals Shear Failure Mode and Concrete Edge Breakout Resistance of Cast-In-Place Anchors in Steel Fiber-Reinforced Normal Strength Concrete

2020 ◽  
Vol 10 (19) ◽  
pp. 6883
Author(s):  
Jong-Han Lee ◽  
Eunsoo Choi ◽  
Baik-Soon Cho
Keyword(s):  
Flexural Strength ◽  
Failure Mode ◽  
Shear Failure ◽  
Steel Fiber ◽  
Shear Resistance ◽  
Fiber Reinforced Concrete ◽  
Steel Fibers ◽  
Embedment Depth ◽  
Fiber Reinforced ◽  
Tensile Performance

Concrete edge failure of a single anchor in concrete is strongly dependent on the tensile performance of the concrete, which can be greatly improved by the addition of steel fibers. This study investigated the effect of steel fibers on the shear failure mode and edge breakout resistance of anchors installed in steel fiber-reinforced concrete (SFRC) with fiber volume percentages of 0.33, 0.67, and 1.00%. The anchor used in the study was 30 mm in diameter, with an edge distance of 75 mm and embedment depth of 240 mm. In addition to the anchor specimens, beam specimens were prepared to assess the relationship between the tensile performance of SFRC beams and the shear resistance of SFRC anchors. The ultimate flexural strength of the beam and the breakout shear resistance of the anchor increased almost linearly with increasing volume fractions of fiber. Therefore, based on the ACI 318 design equation, a term was proposed using the ultimate flexural strength of concrete instead of the compressive strength to determine the concrete breakout shear resistance of an anchor in the SFRC. The calculated shear resistance of anchors in both the plain concrete and SFRC were in good agreement with the measurements. In addition to the load capacity of the SFRC anchors, the energy absorption capacity showed a linear increase with that of the SFRC beam.

Experimental Testing of Shear Resistance on SFRC Slab Structures

2017 ◽  
Vol 893 ◽  
pp. 363-368 ◽  
Author(s):  
Radim Čajka ◽  
Martina Smirakova ◽  
Jana Vašková
Keyword(s):  
Experimental Test ◽  
Experimental Testing ◽  
Shear Resistance ◽  
Steel Fibers ◽  
Foundation Slab ◽  
Physical Quantities

This paper deals with foundation slabs on the subsoil which are not reinforced with classically reinforcement but they are reinforced with steel fibers. It will be described several experimental test of FRC foundation slab which were reinforced with different amount of fibers. All tested slabs had dimension by 2.0 x 2.0 m and thickness 0.15m. On those slab a lot of physical quantities were measured and this paper focus especially on shear resistance.

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