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.

Structural performance of steel fibre reinforced concrete — Part IV. Toughness properties

2014 ◽  
Vol 5 (2) ◽  
pp. 119-125
Author(s):  
I. Kovács
Keyword(s):  
Reinforced Concrete ◽  
Steel Fibre ◽  
Fibre Orientation ◽  
Reinforced Concrete Beams ◽  
Fibre Reinforcement ◽  
Fibre Reinforced Concrete ◽  
Flexural Toughness ◽  
Steel Fibre Reinforced Concrete ◽  
Set Up ◽  
Flexural Tests

The present paper of a series deals with the experimental characterisation of flexural toughness properties of structural concrete containing different volume of hooked-end steel fibre reinforcement (75 kg/m3, 150 kg/m3). Third-point flexural tests were carried out on steel fibre reinforced concrete beams having a cross-section of 80 mm × 85 mm with the span of 765 mm, hence the shear span to depth ratio was 3. Beams were sawn out of steel fibre reinforced slab elements (see Part I) in order to take into consideration the introduced privilege fibre orientation (I and II) and the position of the beam (Ba-a, Ba-b, Ba-c) before sawing (see Part I). Flexural toughness properties were determined considering different standard specifications, namely the method of the ASTM (American Standards for Testing Materials), the process of the JSCE (Japan Society of Civil Engineering), and the final proposal of Banthia and Trottier for the post cracking strength. Consequently, behaviour of steel fibre reinforced concrete was examined in bending taking into consideration different experimental parameters such as fibre content, concrete mix proportions, fibre orientation, positions of test specimens in the formwork, while experimental constants were the size of specimens, the type of fibre used and the test set-up and test arrangement.

Structural performance of steel fibre reinforced concrete — Part II. Compressive behaviour and stress-strain relationship

2014 ◽  
Vol 5 (1) ◽  
pp. 21-33
Author(s):  
I. Kovács
Keyword(s):  
Reinforced Concrete ◽  
Steel Fibre ◽  
Fibre Orientation ◽  
Reinforced Concrete Beams ◽  
Fibre Reinforcement ◽  
Fibre Reinforced Concrete ◽  
Stress Strain ◽  
Steel Fibre Reinforced Concrete ◽  
Compressive Behaviour ◽  
Strain Relationship

Abstract The present paper of a series deals with the experimental characterisation of compressive strength and compressive behaviour (stress-strain relationship) of different structural concrete containing different volume of steel fibre reinforcement (0 V%, 0.5V%, 1.0V%, 75 kg/m3, 150 kg/m3) and different configuration of steel fibres (crimped, hooked-end). Compressive tests were carried out on standard cube (150 mm × 150 mm × 150 mm) and cylinder (Ø = 150 mm, l = 300 mm) specimens considering random fibre orientation. Since the fibre orientation may significantly affect the compressive behaviour, test series were also performed on cylinders (Ø = 70 mm, l = 100 mm) drilled out of fibre reinforced concrete beams and prisms (100 mm × 100 mm × 240 mm) sawn out of steel fibre reinforced deep beams. Throughout the tests stress-strain relationships were registered on the standard cube and cylinder specimens as well. In conclusion, behaviour of steel fibre reinforced concrete was examined in compression taking into consideration different experimental parameters such as fibre content, type of fibres, fibre configuration, fibre orientation, size of specimens (size effect) and concrete mixture.

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.

Structural performance of steel fibre reinforced concrete — Part III. Behaviour in tension

2014 ◽  
Vol 5 (2) ◽  
pp. 105-117
Author(s):  
I. Kovács
Keyword(s):  
Reinforced Concrete ◽  
Steel Fibre ◽  
Fibre Orientation ◽  
Reinforced Concrete Beams ◽  
Tensile Behaviour ◽  
Fibre Reinforcement ◽  
Fibre Reinforced Concrete ◽  
Content Type ◽  
Steel Fibre Reinforced Concrete ◽  
Tensile Splitting Strength

The present paper of a series deals with the experimental characterisation of tensile splitting strength and compressive behaviour of different structural concrete containing different volume of steel fibre reinforcement (0 V%, 0.5 V%, 1.0 V%, 75 kg/m3, 150 kg/m3) and different configuration of steel fibres (crimped, hooked-end). Tensile splitting tests were carried out on standard cylinder (∅ = 150 mm, l = 300 mm) specimens (so-called Brazilian test) considering random fibre orientation. Since the fibre orientation may significantly affect the tensile behaviour test series were also performed on cross-section (100 mm × 100 mm) of steel fibre reinforced concrete beams (100 mm × 100 mm × 240 mm) sawn out of steel fibre reinforced slab elements. Taken as a whole behaviour of steel fibre reinforced concrete was examined in tension taking into consideration different experimental parameters such as fibre content, type of fibres, fibre configuration, fibre orientation, size of specimens (size effect) and concrete mixture.

Adding an expansive agent to increase the toughness of steel fibre reinforced concrete

2019 ◽  
Vol 26 (4) ◽  
pp. 197-208
Author(s):  
Leo Gu Li ◽  
Albert Kwok Hung Kwan
Keyword(s):  
Reinforced Concrete ◽  
Steel Fibre ◽  
The Other ◽  
Fibre Reinforced Concrete ◽  
Test Results ◽  
Compressive Properties ◽  
Shrinkage Cracking ◽  
Steel Fibre Reinforced Concrete ◽  
Expansive Agent ◽  
Concrete Matrix

Previous research studies have indicated that using fibres to improve crack resistance and applying expansive agent (EA) to compensate shrinkage are both effective methods to mitigate shrinkage cracking of concrete, and the additions of both fibres and EA can enhance the other performance attributes of concrete. In this study, an EA was added to fibre reinforced concrete (FRC) to produce concrete mixes with various water/binder (W/B) ratios, steel fibre (SF) contents and EA contents for testing of their workability and compressive properties. The test results showed that adding EA would slightly increase the superplasticiser (SP) demand and decrease the compressive strength, Young’s modulus and Poisson’s ratio, but significantly improve the toughness and specific toughness of the steel FRC produced. Such improvement in toughness may be attributed to the pre-stress of the concrete matrix and the confinement effect of the SFs due to the expansion of the concrete and the restraint of the SFs against such expansion.

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