Post-Fire Flexural Tensile Strength of Macro Synthetic Fibre Reinforced Concrete

2020 ◽  
pp. 140-150
Author(s):  
Olivia Mirza ◽  
Brendan Kirkland ◽  
Kurt Bogart ◽  
Todd Clarke
Keyword(s):  
Tensile Strength ◽  
Reinforced Concrete ◽  
Synthetic Fibre ◽  
Fibre Reinforced Concrete ◽  
Flexural Tensile Strength

scholarly journals The effect of macro polymer fibres length and content on the fibre reinforced concrete

2018 ◽  
Vol 219 ◽  
pp. 03004 ◽  
Author(s):  
Aleksandra Mariak ◽  
Marzena Kurpińska
Keyword(s):  
Tensile Strength ◽  
Reinforced Concrete ◽  
Volume Fraction ◽  
Concrete Strength ◽  
Fibre Volume Fraction ◽  
Fibre Length ◽  
Fibre Volume ◽  
Concrete Mixture ◽  
Fibre Reinforced Concrete ◽  
Flexural Tensile Strength

The paper presents studies of a ready-mix concrete containing polymer fibres of three different lengths: 24, 38 and 54 mm. The performed tests allowed to determine the effect of fibre volume fraction and length on the concrete strength. The basic parameters of concrete mixture (consistency, air content and bulk density) were identified. Fibre reinforced concrete belongs to a group of composite materials. The polymer fibres are applied in the concrete in structures where the reduction of shrinkage cracking as well as corrosion resistance and fire temperatures are required. It is widely known, that the cracking behaviour of concrete structures depends on flexural tensile strength of concrete. The addition of fibres significantly improves the tensile strength. The experimental study, including axial compressive strength and center-point loading flexural tensile strength, was carried out. The scope of the research was also expanded by the usage of a scanning microscope. The test results showed the effect of fibre length and fibre combinations on mechanical properties of concrete. The effect of the research is to formulate guidelines due to the quantity of macro polymer fibres. In general, appropriate fibre content brings a beneficial effect e.g. improves better workability of a concrete mixture.

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 Investigative Study of Chicken Feather and Synthetic Hair Fibre on Mechanical and Microstructural Properties of Interlocking Concrete Block

2021 ◽  
Vol 7 (2) ◽  
Author(s):  
S. O. Adetola
Keyword(s):  
Tensile Strength ◽  
Reinforced Concrete ◽  
Physical And Mechanical Properties ◽  
Heterogeneous Material ◽  
Concrete Block ◽  
Fibre Reinforced Concrete ◽  
Chicken Feather ◽  
Split Tensile Strength ◽  
Mechanical And Microstructural Properties ◽  
Hair Fibre

Efforts have been made to improve the quality and performance of concrete structures especially its permeability and durability properties. Concrete is a heterogeneous material containing several components (sand, aggregate, cement, etc.) which vary in size and geometry, and their positions in the concrete enclosure are randomly distributed, giving them defects even before experiencing any form of mechanical loading. In this study, the compositions of Chicken Feather Fibre (CFF) and Synthetic Hair Fibre (SHF) by weight were varied by 0%, 1.5%, 2.5%, 3.5% and 5% for Samples A to E respectively. Physical and Mechanical properties such as water absorption (WA), thickness swelling (TS), compressive and split tensile strength were determined. Results showed that WA and TS property of the fibre reinforced concrete block decreased with decrease in percentage by weight of CFF and SHF and curing days with highest value being 10.01 to a lowest value of 0.14. Also, compressive strength (CS) for sample A increased with increase in curing days from 16.98MPa at 7 days to 20.66MPa at 28 days and sample B has its highest CS at 14 days with 9.98 MPa while other samples decreased progressively. Split Tensile Strength (STS) for sample A increases with increase in curing days from 9.84MPa to 13.64MPa while sample B decreases from 7 to 21 days of curing from 5.43MPa to 4.79MPa and increased at 28 days to 4.92MPa. Samples C, D and E follow same trend as sample B. The SEM study shows that the interlocking concrete block (ICB) containing 0% of chicken feather and synthetic hair fibre has brittle characteristics while other samples containing different percentage by weight of chicken feather and synthetic hair fibre shows ductile characteristics. CFF and SHF enhanced WA, TS, CS and STS of fibre reinforced concrete.

scholarly journals Effect of Jute Fibre Orientation and Percentage on Strength of Jute Fibre Reinforced Concrete

2020 ◽  
Vol 9 (3) ◽  
pp. 1767-1770
Keyword(s):  
Tensile Strength ◽  
Reinforced Concrete ◽  
Dynamic Properties ◽  
Low Cost ◽  
Plain Concrete ◽  
Natural Fibre ◽  
Fibre Reinforced Concrete ◽  
Jute Fibre ◽  
Micro Cracks ◽  
Crack Arrester

The demerits of plain concrete are its lesser tensile strength, not significant ductility and poor resistance to cracking. Due to propagation of internal micro cracks in plain concrete causes decrease in tensile strength, hence leads concrete to brittle fracture. Addition of fibres behaves like crack arrester and enhances the dynamic properties of concrete. In India natural fibres such as bamboo, coir, jute, sisal, pineapple, banana, ramie etc are high available. Jute is a useful natural fibre for concrete reinforcement due to its easy availability and low cost. In this research, the experiments related to Jute fibre reinforced concrete (JFRC) are done by taking different fibre percentage and the compressive strength and modulus of rapture value observed. This JFRC can replace plain concrete and wood in many cases for example in door and window panels, inclined roof slabs, partition walls etc

scholarly journals Performance of ultra-high performance fibre reinforced concrete plates under impact loads

2021 ◽  
Author(s):  
Hesham Othman
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Reinforced Concrete ◽  
Fracture Energy ◽  
High Performance ◽  
Steel Reinforcement ◽  
Fibre Content ◽  
Fibre Reinforced Concrete ◽  
Concrete Plates ◽  
High Performance Fibre

The next generation of concrete, Ultra-High Performance Fibre Reinforced Concrete (UHP-FRC), exhibits exceptional mechanical characteristics. UHP-FRC has a compressive strength exceeding 150 MPa, tensile strength in the range of 8-12 MPa, and fracture energy of several orders of magnitudes of traditional concrete. The focus of this research is to investigate and analyze the advantage of using UHP - FRC in impact resistance structures. To achieve these goals, two experimental testing programs and major numerical investigations have been conducted. The material experimental investigation has been conducted to determine the effects of strain rate on UHP - FRC. Two parameters are investigated, namely: compressive strength (80, 110, 130, and 150 MPa); and steel fibre content (0, 1, 2, and 3%). Experimental results showed that the rate sensitivity decreases with the increase in the compressive strength ; and the dynamic enhancement of tensile strength is inversely proportional to the fibre content. The structural impact testing program focuses on the dynamic response of full - scale reinforced concrete plates as well as generating precise impact measurements. Twelve reinforced plates with identical dimensions are tested under high-mass low-velocity multi-impacts. The investigated parameters include: concrete type (NSC, HSC, and UHP - FRC), fibre volume content, and steel reinforcement ratio. The results showed that the use of UHP -FRC instead of NSC or HSC is able to change the failure mode from punching to pure flexural; and UHP -FRC containing 3% fibre has superior dynamic properties. For plates with identical steel reinforcement, the total impact energy of UHP-FRC plate containing 3% fibres is double the capacity of UHP - FRC plate containing 2% fibres , and 18 times the capacity of NSC plate. A three-dimensional finite element analysis has been performed using ABAQUS/Explicit to model multi-impacts on RC plates and the applicability is verified using existing experimental data. Concrete damage plasticity (CDP) model is adapted to define UHP - FRC. The CDP constitutive model parameters for the new material are calibrated through a series of parametric studies. Computed responses are sensitive to CDP parameters related to the tension, fracture energy, and expansion properties. The analytical results showed that the existing CDP model can predict the response and crack pattern of UHP - FRC reasonably well.

scholarly journals Impact of twisting high-performance polyethylene fibre bundle reinforcements on the mechanical characteristics of high-strength concrete

2019 ◽  
Vol 69 (334) ◽  
pp. 184
Author(s):  
Y. Zhang ◽  
L. Yan ◽  
S. Wang ◽  
M. Xu
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Reinforced Concrete ◽  
Strain Rate ◽  
Uniform Distribution ◽  
Dynamic Compression ◽  
Splitting Tensile Strength ◽  
Fibre Reinforced Concrete ◽  
Compressive Strength Of Concrete ◽  
Concrete Matrix

The quasi-static and dynamic mechanical behaviours of the concrete reinforced by twisting ultra-high molecular weight polyethylene (UHMWPE) fibre bundles with different volume fractions have been investigated. It was indicated that the improved mixing methodology and fibre geometry guaranteed the uniform distribution of fibres in concrete matrix. The UHMWPE fibres significantly enhanced the splitting tensile strength and residual compressive strength of concrete. The discussions on the key property parameters showed that the UHMWPE fibre reinforced concrete behaved tougher than the plain concrete. Owing to the more uniform distribution of fibres and higher bonding strength at fibre/matrix interface, the UHMWPE fibre with improved geometry enhanced the quasi-static splitting tensile strength and compressive strength of concrete more significantly than the other fibres. The dynamic compression tests demonstrated that the UHMWPE fibre reinforced concrete had considerable strain rate dependency. The bonding between fibres and concrete matrix contributed to the strength enhancement under low strain-rate compression.

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