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.

Experimental study of the tensile and flexural mechanical properties of directionally distributed steel fibre-reinforced concrete

2018 ◽  
Vol 233 (9) ◽  
pp. 1721-1732 ◽  
Author(s):  
Fangyuan Li ◽  
Yunxuan Cui ◽  
Chengyuan Cao ◽  
Peifeng Wu
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Reinforced Concrete ◽  
Steel Fibre ◽  
Plain Concrete ◽  
Design Parameters ◽  
Fibre Reinforced Concrete ◽  
Split Tensile Strength ◽  
Fibre Direction ◽  
Steel Fibre Reinforced Concrete

Directionally distributed steel fibre-reinforced concrete has been proposed as a novel concrete because of its high tensile strength and crack resistance in specific directions. Based on the existing studies of the effect of the fibre direction on the mechanical properties of fibre-reinforced concrete, the authors in this paper performed further studies of the mechanical properties of directionally distributed steel fibre-reinforced concrete by conducting split tensile and bending tests. The split tensile strength of the directionally distributed fibre-reinforced concrete clearly exhibited anisotropy. The split tensile strength perpendicular to the fibre direction was much higher than that parallel to the fibre direction. The split tensile strength perpendicular to the fibre direction was almost twice the tensile strength of plain concrete. The flexural performance of directionally distributed fibre-reinforced concrete in the fibre direction significantly improved compared to that of randomly distributed fibre-reinforced concrete. Specifically, the flexural strength increased by as much as 97%. Gravity resulted in a deviation in the tensile properties of concrete prepared by manually and directionally placing fibres in a layered casting process. The test results can be utilised in subsequent concrete designs. The conclusions reached in this paper provide comprehensive mechanical design parameters for the application of directionally distributed fibre-reinforced concrete.

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.

Experiment Study on Mechanics and Pore Structure of Steel Fibre Reinforced Concrete

2010 ◽  
Vol 150-151 ◽  
pp. 825-828
Author(s):  
Yan Wang ◽  
Di Tao Niu ◽  
Yuan Yao Miao ◽  
Nai Qi Jiao
Keyword(s):  
Mechanical Properties ◽  
Experimental Study ◽  
Reinforced Concrete ◽  
Pore Structure ◽  
Steel Fibre ◽  
Fibre Reinforced Concrete ◽  
Experiment Study ◽  
Steel Fibre Reinforced Concrete ◽  
Mercury Intrusion ◽  
Strength And Durability

The concrete microstructure can affect its macroscopic properties, such as the strength and durability, etc. Based on the experimental study of cube compressive strength of steel fibre reinforced concrete, splitting tensile strength, flexural strength, and using by mercury intrusion method to test the pore structure of steel fibrous, this paper analyzes the influence of fibre on concrete pore structure. And then on mechanical properties of concrete from microcosmic perspective.

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.

scholarly journals Comparison of Mechanical Properties of Normal and Fibre Reinforced Concrete (Grade M15)

2019 ◽  
Vol 5 ◽  
pp. 153-164
Author(s):  
Sagar Bista ◽  
Sagar Airee ◽  
Shikshya Dhital ◽  
Srijan Poudel ◽  
Sujan Neupane
Keyword(s):  
Mechanical Properties ◽  
Reinforced Concrete ◽  
Steel Fibre ◽  
Residential Buildings ◽  
Fibre Reinforced Concrete ◽  
Cement Concrete ◽  
Normal Concrete ◽  
Steel Fibre Reinforced Concrete ◽  
Cracking Control ◽  
Different Types

Concrete is weak in tension, hence some measures must be adopted to overcome this deficiency as well as to enhance physical and other mechanical properties but in more convenient and economical method. Through many research from the past, it has been observed that addition of different types of fibres has been more effective for this purpose. This report presents the work undertaken to study the effect of steel and hay fibre on normal cement concrete of M-15 Grade on the basis of its mechanical properties which include compressive and tensile strength test and slump test as well. Although hay fibres are abundantly available in Nepal, no research have been popularly conducted here regarding the use of hay fibres in concrete and the changes brought by it on concrete’s mechanical properties. Experiments were conducted on concrete cubes and cylinders of standard sizes with addition of various percentages of steel and hay fibres i.e. 0.5%, 1% and 1.5% by weight of cement and results were compared with those of normal cement concrete of M-15 Grade. For each percentage of steel and hay fibre added in concrete, six cubes and six cylinders were tested for their respective mechanical properties at curing periods of 14 and 28 days. The results obtained show us that the optimum content of fibre to be added to M-15 grade of concrete is 0.5% steel fibre for compression and 0.5% hay fibre content for tension by weight of cement. Also, addition of steel and hay fibres enhanced the binding properties, micro cracking control and imparted ductility. In addition to this, two residential buildings were modeled in SAP software, one with normal concrete and other with concrete containing 0.5% steel fibre. Difference in reinforcement requirements in each building was computed from SAP analysis and it was found that 489.736 Kg of reinforcement could be substituted by 158.036 kg of steel fibres and decrease in materials cost of building with 0.5% steel fibre reinforced concrete was found to be Rs. 32,100.

scholarly journals Study of the Effect of Fibre Orientation on Artificially Directed Steel Fibre-Reinforced Concrete

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Fang-Yuan Li ◽  
Liu-Yang Li ◽  
Yan Dang ◽  
Pei-Feng Wu
Keyword(s):  
Reinforced Concrete ◽  
Steel Fibre ◽  
Fibre Orientation ◽  
Utilization Efficiency ◽  
Boundary Effects ◽  
Layer By Layer ◽  
Fibre Reinforced Concrete ◽  
Fibre Direction ◽  
Steel Fibre Reinforced Concrete ◽  
Better Than

The fibre utilization efficiency of directionally distributed fibre-reinforced concrete is better than that of randomly distributed fibre. However, controlling the fibre direction is difficult, which limits its applications. In this paper, a method in which fibres were artificially directed was used to simulate the feasibility of orienting fibres during 3D concrete printing. Based on artificially directed steel fibre-reinforced concrete specimens, the orientation characteristics of directional fibre-reinforced concrete specimens were studied. The differences between the gravity and the boundary effects in ordinary fibre-reinforced concrete and artificially directed fibre-reinforced concrete were compared. The average orientation coefficient in randomly distributed fibre-reinforced concrete was 0.59, whereas this value in directionally distributed fibre-reinforced concrete was over 0.9. This result demonstrated the feasibility of manually orienting the fibres in steel fibre-reinforced concrete in layer-by-layer casting.

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.

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