scholarly journals Investigation on the Effect of Varying Dosages of Steel Fibre on the Strength and Workability Properties Of High Strength Concrete

10.29007/rjbd ◽  
2018 ◽  
Author(s):  
Deepa Sinha ◽  
Arvindkumar Verma
Keyword(s):  
Steel Fibre ◽  
Steel Fiber ◽  
Volume Fraction ◽  
High Strength ◽  
Particle Packing ◽  
Fibre Reinforced Concrete ◽  
Steel Fibres ◽  
Steel Fibre Reinforced Concrete ◽  
Coarse Aggregates ◽  
Packing Method

In this work the strength characteristics of steel fibre reinforced concrete with varying percentages of fibres is found and hence arrived at optimum percentage of steel fibres. M60 grade concrete as per particle packing method was designed with cement, sand and coarse aggregates (10mm and 20mm) which yielded a proportion of 1:1.79:1.11:2.08 with a w/c ratio of 0.30. The steel fibres were added at the rate of 0.5%, 0.75%, 1.0%, 1.25%, 1.50%, 1.75%, and 2.0% by volume fraction. Based on the compressive strength and tensile strength it is concluded that the optimum percentage of steel fiber to be added in the concrete mix is 1% by volume fraction.

scholarly journals Experimental Study of the Basic Mechanical Properties of Directionally Distributed Steel Fibre-Reinforced Concrete

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Fang-Yuan Li ◽  
Cheng-Yuan Cao ◽  
Yun-Xuan Cui ◽  
Pei-Feng Wu
Keyword(s):  
Mechanical Properties ◽  
Elastic Modulus ◽  
Steel Fibre ◽  
Volume Fraction ◽  
Fibre Reinforced Concrete ◽  
Transverse Deformation ◽  
Fibre Direction ◽  
Steel Fibres ◽  
Steel Fibre Reinforced Concrete ◽  
Ordinary Concrete

Directionally distributed steel fibre-reinforced concrete (SFRC) cannot be widely applied due to the limitations of current construction technology, which hinders research on its mechanical properties. With the development of new construction technologies, such as self-compacting concrete or 3D printing, directionally distributed SFRC has found new developmental opportunities. This study tested, compared, and analysed the basic mechanical properties of ordinary concrete, randomly distributed SFRC, and directionally distributed SFRC. The differences between the damage patterns parallel and perpendicular to the direction of the steel fibres were evaluated in directionally distributed SFRC. When the fibre volume fraction is high and the compression is applied perpendicular to the fibre direction, as the loading increases, the transverse deformation of the specimen is constrained by the fibres. When the compression is applied parallel to the fibre direction, the fibre cannot effectively constrain the transverse deformation of the specimens. When the volume fraction of directionally distributed steel fibres was 1.6%, the elastic modulus of the directionally distributed steel fibres was 39% higher than that of ordinary concrete. Comparison of the experimental values of the elastic modulus with those estimated by existing calculation methods revealed that a modification of the current calculation theories may be required to calculate the changes in the elastic modulus of directionally distributed SFRC with a high volume fraction of steel fibres.

scholarly journals Experimental Investigation of Shear Strength for Steel Fibre Reinforced Concrete Beams

2021 ◽  
Vol 15 (1) ◽  
pp. 81-92
Author(s):  
Constantinos B. Demakos ◽  
Constantinos C. Repapis ◽  
Dimitros P. Drivas
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Shear Strength ◽  
Reinforced Concrete ◽  
Steel Fibre ◽  
Concrete Beams ◽  
Reinforced Concrete Beams ◽  
Fibre Reinforced Concrete ◽  
Steel Fibres ◽  
Steel Fibre Reinforced Concrete

Aims: The aim of this paper is to investigate the influence of the volume fraction of fibres, the depth of the beam and the shear span-to-depth ratio on the shear strength of steel fibre reinforced concrete beams. Background: Concrete is a material widely used in structures, as it has high compressive strength and stiffness with low cost manufacturing. However, it presents low tensile strength and ductility. Therefore, through years various materials have been embedded inside it to improve its properties, one of which is steel fibres. Steel fibre reinforced concrete presents improved flexural, tensile, shear and torsional strength and post-cracking ductility. Objective: A better understanding of the shear performance of SFRC could lead to improved behaviour and higher safety of structures subject to high shear forces. Therefore, the influence of steel fibres on shear strength of reinforced concrete beams without transverse reinforcement is experimentally investigated. Methods: Eighteen concrete beams were constructed for this purpose and tested under monotonic four-point bending, six of which were made of plain concrete and twelve of SFRC. Two different aspect ratios of beams, steel fibres volume fractions and shear span-to-depth ratios were selected. Results: During the experimental tests, the ultimate loading, deformation at the mid-span, propagation of cracks and failure mode were detected. From the tests, it was shown that SFRC beams with high volume fractions of fibres exhibited an increased shear capacity. Conclusion: The addition of steel fibres resulted in a slight increase of the compressive strength and a significant increase in the tensile strength of concrete and shear resistance capacity of the beam. Moreover, these beams exhibit a more ductile behaviour. Empirical relations predicting the shear strength capacity of fibre reinforced concrete beams were revised and applied successfully to verify the experimental results obtained in this study.

Bond Behaviour of Frp Reinforcing Bars in High-Strength Steel Fibre-Reinforced Concrete

2007 ◽  
Vol 15 (7) ◽  
pp. 569-578 ◽  
Author(s):  
Jong-Pil Won ◽  
Chan-Gi Park ◽  
Hwang-Hee Kim ◽  
Sang-Woo Lee ◽  
Cheol Won
Keyword(s):  
Reinforced Concrete ◽  
High Strength Steel ◽  
High Strength Concrete ◽  
Steel Fibre ◽  
High Strength ◽  
Fibre Reinforced Concrete ◽  
Reinforcing Bars ◽  
Bond Behaviour ◽  
Steel Fibre Reinforced Concrete ◽  
Pullout Load

Current design trends for structures require the increased use of high-strength concrete, which has a compressive strength of over 80 MPa. Its enhanced strength, however, leads to brittle failure problems, which have been resolved by adding steel fibres. Fibre-reinforced polymer (FRP) is actively being studied to resolve the corrosion problems encountered with steel reinforcing bars in concrete structures exposed to adverse environmental conditions. In this study, we experimentally evaluated the bond behaviour of FRP reinforcing bars in high-strength steel fibre-reinforced concrete. A high-strength concrete mix was created with a target strength of over 80 MPa, and steel fibre was added. The FRP reinforcing bars had an increased pullout load with a slow gradient, and the slope of the pullout load reduction curve remained small after the maximum pullout load was reached. In addition, the bond strength increased as steel fibre was added to the FRP reinforcing bar.

Experimental Study of Steel Fibre Bridging Action on Crack Propagation in Fibre Reinforced Concrete

2006 ◽  
Vol 324-325 ◽  
pp. 1067-1070 ◽  
Author(s):  
Zhi Hong Xu ◽  
Wen Yin Liang ◽  
Yu Jing Liang
Keyword(s):  
Reinforced Concrete ◽  
Crack Propagation ◽  
Steel Fibre ◽  
Fibre Reinforced Concrete ◽  
Interfacial Bond ◽  
Cycle Number ◽  
Steel Fibres ◽  
Steel Fibre Reinforced Concrete ◽  
Fibre Bridging ◽  
The Matrix

In this paper the bridging action of steel fibres on the model I crack propagation has been studied experimentally for steel fibre reinforced concrete (FRC). From the experimental results three main conclusions are obtained. First, the bridging action increases with the number of the steel fibres across the crack surface and the stress intensity factor near the crack tip decreases thereby. Second, bridging action increases with the strength of the matrix because the matrix with higher strength can provide stronger interfacial bond with steel fibres. Third, the interfacial bonding gets damaged when the steel fibres under cyclic loads and the bridging action degrades with the cycle number.

Experimental Tests of Steel Fibre Reinforced Concrete Beams under Drop-Weight Impacts

2014 ◽  
Vol 626 ◽  
pp. 311-316 ◽  
Author(s):  
Yi Fei Hao ◽  
Hong Hao ◽  
Gang Chen
Keyword(s):  
Reinforced Concrete ◽  
Steel Fibre ◽  
Concrete Beams ◽  
Plain Concrete ◽  
Fibre Reinforced Concrete ◽  
Steel Fibres ◽  
Steel Fibre Reinforced Concrete ◽  
Impact Tests ◽  
Drop Weight ◽  
The Impact

Concrete is a brittle material, especially under tension. Intensive researches have been reported to add various types of fibres into concrete mix to increase its ductility. Recently, the authors proposed a new type of steel fibre with spiral shape to reinforce concrete material. Laboratory tests on concrete cylinder specimens demonstrated that compared to other fibre types such as the hooked-end, deformed and corrugated fibres the new fibres have larger displacement capacity and provide better bonding with the concrete. This study performs drop-weight impact tests to investigate the behaviour of concrete beams reinforced by different types of steel fibres. The quasi-static compressive and split tensile tests were also conducted to obtain the static properties of plain concrete and steel fibre reinforced concrete (FRC) materials. The quasi-static tests were carried out using hydraulic testing machine and the impact tests were conducted using an instrumented drop-weight testing system. Plain concrete and concrete reinforced by the commonly used hooked-end steel fibres and the proposed spiral-shaped steel fibres were tested in this study. The volume dosage of 1% fibre was used to prepare all FRC specimens. Repeated drop-weight impacts were applied to the beam specimens until total collapse. A 15.2 kg hard steel was used as the drop-weight impactor. A drop height of 0.5 m was considered in performing the impact tests. The force-displacement relations and the energy absorption capabilities of plain concrete and FRC beams were obtained, compared and discussed. The advantage and effectiveness of the newly proposed spiral-shaped steel fibres in increasing the performance of FRC beam elements under impact loads were examined.

Effects of Fibre Geometry and Volume Fraction on the Flexural Behaviour of Steel-Fibre Reinforced Concrete

Strain ◽  
2009 ◽  
Vol 47 ◽  
pp. e535-e541 ◽  
Author(s):  
D. V. Soulioti ◽  
N. M. Barkoula ◽  
A. Paipetis ◽  
T. E. Matikas
Keyword(s):  
Reinforced Concrete ◽  
Steel Fibre ◽  
Volume Fraction ◽  
Fibre Reinforced Concrete ◽  
Flexural Behaviour ◽  
Steel Fibre Reinforced Concrete
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