Constitutive Behaviour of Lateral Ties Confined Polyolefin Fibre Reinforced Concrete under Monotonic Axial Compression

2012 ◽  
Vol 253-255 ◽  
pp. 367-375 ◽  
Author(s):  
S. Palanivel ◽  
M. Sekar
Keyword(s):  
Reinforced Concrete ◽  
Volume Fraction ◽  
Secondary Reinforcement ◽  
Fiber Reinforced Concrete ◽  
Constitutive Behaviour ◽  
Fiber Reinforced ◽  
Behavioral Differences ◽  
Synthetic Fibers ◽  
The Matrix ◽  
Low Modulus

In this investigation, the combined effect of spacing of lateral ties and volume fraction of polyolefin fibres was studied both experimentally and analytically from the point of deformability characteristics of concrete. Low modulus synthetic fibers such as polyolefin based fibers, it is shown that polyolefin fibers with sufficient tensile strength can successfully enhance the mechanical properties of concrete. The mechanism of delaying and arresting the progressive internal cracking from transition zone to the matrix by the fibres can be made use in passive confinement of concrete. Such concrete was termed as polyolefin fiber reinforced concrete (PFRC). In this study the confinement effectiveness of polyolefin fibres of volume fractions 0.3%,0.5%,0.7%,0.9% and 1.2% in addition to lateral ties of spacing 290mm, 145mm and 75mm on concrete prisms of size 150 ×150 ×300 mm were investigated. Such concrete is termed as confined polyolefin fiber reinforced concrete (CPFRC).This paper presents an analytical model(profile) for predicting the constitutive behaviour of CPFRC based on the experimental and analytical results. A total of seventy two prisms of size 150 ×150 ×300 mm were cast and tested under strain control rate of loading. The increase in strength and strain of CPFRC were used in formulating the constitutive relation. The results of the testing demonstrate the behavioral differences between plain and CPFRC and the ability of the synthetic macro fiber to be used as secondary reinforcement in seismic resistance applications.

Experimental and Numerical Investigation on Stress-Strain Relationships of GFRP and Lateral Ties Confined Polyolefin Fibre Reinforced Concrete under Monotonic Axial Compression

2012 ◽  
Vol 253-255 ◽  
pp. 466-473 ◽  
Author(s):  
S. Palanivel ◽  
M. Sekar
Keyword(s):  
Reinforced Concrete ◽  
Volume Fraction ◽  
Secondary Reinforcement ◽  
Fiber Reinforced Concrete ◽  
Seismic Resistance ◽  
Behavioral Differences ◽  
Synthetic Fibers ◽  
Reinforced Polymer ◽  
Fibre Reinforced Polymer ◽  
Low Modulus

In this investigation, the combined confinement effect of spacing of lateral ties, volume fraction of polyolefin fibres and fibre reinforced polymer(FRP) wraps was studied both experimentally and analytically from the point of deformability characteristics of concrete for seismic resistance. Low modulus synthetic fibers such as polyolefin based fibers, it is shown that polyolefin fibers with sufficient tensile strength can successfully enhance the mechanical properties of concrete. The mechanism of delaying and arresting the progressive internal cracking by the fibres can be made use in passive confinement of concrete. In this study the confinement effectiveness of GFRP wraps of single and double layer and polyolefin fibres of volume fractions 0.7% and 0.9% in addition to lateral ties of spacing 145mm and 75mm on concrete prisms of size 150 ×150 ×300 mm were investigated. Such concrete is termed as FRP confined fiber reinforced concrete(FRPCFRC).This paper presents an analytical model(profile) for predicting the constitutive behaviour of FRPCFRC based on the experimental and analytical results. A total of thirty nine prisms of size 150 ×150 ×300 mm were cast and tested under strain control rate of loading. The results of the testing demonstrate the behavioral differences between FRP confined concrete and FRP confined FRC and the ability of the synthetic macro fiber to be used as secondary reinforcement in performance based seismic resistance applications.

Strain Rate Effects on Tensile Properties of Fiber Reinforced Concrete

1985 ◽  
Vol 64 ◽  
Author(s):  
George G. Nammur ◽  
Antoine E. Naaman
Keyword(s):  
Reinforced Concrete ◽  
Strain Rate ◽  
Volume Fraction ◽  
Tensile Tests ◽  
Fiber Reinforced Concrete ◽  
Fiber Reinforced ◽  
Steel Fiber Reinforced Concrete ◽  
Strain Rate Effects ◽  
Rate Effects ◽  
The Matrix

ABSTRACTHigh strain rates lead to substantial modifications in the stress-strain (or stress-displacement) response of fiber reinforced concrete in tension. These modifications include higher strength and corresponding strain, as well as smaller displacement at failure.The purpose of this paper is to investigate the behavior of fiber reinforced concrete under impact tensile loading, and to study the effect of strain rate on the post-cracking strength of the composite. The variation of the tensile strength of the matrix with the reinforcement parameters such as volume fraction Vf and aspect ratio |/φ of the fibers is also studied ip this paper. A special emphasis is placed on the stress-displacement relationship of steel fiber reinforced concrete in its post-cracking range. An empirical model of the stress- displacement relationship as a function of the strain rate is developed from experimental data from tensile tests on dogbone shape notched tensile prisms. The model highlights the effects of strain rate and fiber properties on the post-cracking strength of the composite, as well as the displacement at failure. The effect of strain rate on the post-cracking toughness of fiber reinforced concrete is also addressed. The literature on impact effects on concrete in tension (plain and fiber reinforced) is briefly reviewed in this paper, and so is the state of the art of testing techniques for strain rate effects.

scholarly journals Modelling the behavior of fiber-reinforced concrete with low-modulus fibers under load

2020 ◽  
Vol 329 ◽  
pp. 04002
Author(s):  
Yury V. Pukharenko ◽  
Dmitrii A. Panteleev ◽  
Mikhail I. Zhavoronkov ◽  
Maxim P. Kostrikin ◽  
Said Mujtaba Eshanzada
Keyword(s):  
Reinforced Concrete ◽  
Polypropylene Fiber ◽  
Theoretical Models ◽  
Fiber Reinforced Concrete ◽  
Polypropylene Fibers ◽  
Mechanical Modeling ◽  
Fiber Reinforced ◽  
The Matrix ◽  
Low Modulus

In this work was carried out a study the purpose of which was the development of physical and mechanical modeling of the processes of deformation and destruction of fiber-reinforced concrete. The process of deformation and the mechanism of destruction of fiber-reinforced concrete reinforced with low-modulus polypropylene fibers have been investigated. The method has been improved and the characteristic of adhesion of polypropylene fiber to the matrix has been determined. Theoretical models for forecasting the behavior of fiber-reinforced concrete reinforced with polypropylene fiber under load have been developed.

scholarly journals Exploration of Characteristics of Steel Fiber Reinforced Concrete and Its Influence on Regular Concrete

2020 ◽  
Vol 9 (2) ◽  
pp. 209-212
Keyword(s):  
Reinforced Concrete ◽  
Steel Fiber ◽  
Volume Fraction ◽  
Natural Fibers ◽  
Plain Concrete ◽  
Fiber Content ◽  
Fiber Reinforced Concrete ◽  
Fiber Reinforced ◽  
Steel Fiber Reinforced Concrete ◽  
Synthetic Fibers

Concrete is the most widely used product in the construction sector mainly because of its properties and its capability to be moulded to any size. Plain concrete has low tensile strength and forms internal micro cracks. It has been proven that with the addition of natural fibers and synthetic fibers in concrete, it helps in the durability and functionality of structure. The steel fibers are added to the concrete in very low volume doses and it has been effective in decreasing the plastic shrinkage in cracking and also acting as a crack arrestor. In this journal, experimental analysis on steel fiber reinforced concrete is done on M30 and M50 mix with 0.5%, 1%, 1.5% and 2% volume fraction of steel fiber content and is compared with samples of 0% steel fiber content and these samples are investigated on their compressive, split tensile and flexural strengths.

EVALUATION OF COMPRESSIVE STRENGTH OF SYNTHETIC FIBER REINFORCED CONCRETE

2020 ◽  
Vol 7 (1) ◽  
Author(s):  
Saman Hedjazi ◽  
Daniel Castillo
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Reinforced Concrete ◽  
Fiber Volume Fraction ◽  
Volume Fraction ◽  
Fiber Reinforced Concrete ◽  
Synthetic Fiber ◽  
Fiber Reinforced ◽  
Fiber Volume ◽  
Synthetic Fibers

This paper evaluates the effect of discrete fibers in concrete on the pulse velocity and mechanical properties of FRC. Two different type of synthetic fibers consisting of Polypropylene and Nylon were investigated. The effect of concrete mix proportions such as types of fiber, volume fraction of fiber, water-to-cement ratio (w/c), and curing conditions were examined. An experimental program was designed and conducted on 100 mm x 200 mm cylindrical specimens to evaluate the properties of FRC. The compressive strength obtained from the Compression Test Machine (CTM) was compared to those calculated from UPV. The difference between two types of synthetic fibers on concrete properties were investigated. Results show that the highest compressive strength of Polypropylene Fiber Reinforced Concrete (PFRC) was achieved at 0.5% fiber volume fraction, whereas for Nylon Fiber Reinforced Concrete (NFRC) the highest compressive strength was obtained at 1.0% fiber volume fraction. Additionally, results show that the available equations relating UPV to compressive strength of concrete need modifications when used for different fibers. Therefore, either new or modified empirical equations are needed for better estimation of mechanical properties of FRC.

Static Behavior of Layered Fiber Reinforced Concrete T-Shaped Beam

2010 ◽  
Vol 168-170 ◽  
pp. 2037-2043
Author(s):  
Yin Gu ◽  
Wei Dong Zhuo ◽  
Yu Ting Qiu
Keyword(s):  
Reinforced Concrete ◽  
Volume Fraction ◽  
Fiber Reinforced Concrete ◽  
Parameter Analysis ◽  
Beam Specimen ◽  
Rc Beam ◽  
High Modulus ◽  
Fiber Reinforced ◽  
Initial Stiffness ◽  
Fiber Volume

This paper proposes a concept of layered fiber reinforced concrete (LFRC) beam. In the concept of a LFRC beam, low-modulus fiber and high-modulus fiber are randomly dispersed and uniformly distributed into the concrete matries of the compression and tension zones, respectively. The static behaviors of LFRC beam are investigated from both experimental and numerical aspects. Four-point bending tests are performed on two simply supported T-shaped LFRC beam specimens and an ordinary T-shaped RC beam specimen with large scales. Comparison between the testing results of LFRC and RC beam specimens shows that the initial cracking load, flexural toughness and post-yielding stiffness of a LFRC beam can be significantly improved, but the ultimate loads are nearly without change. Numerical simulations are also carried out to investigate the static behaviors of the LFRC beam specimens. It is found that the simulation results are agreed well with that of tests. Further numerical parameter analysis for the LFRC beam specimens is conducted. The effects of high-modulus fiber volume fraction on the static behaviors of LFRC beams are studied. The research results show that the additions of high-modulus fibers have little effect on the initial stiffness, yielding loads and ultimate loads of LFRC beams; both the load and displacement at the initial cracking point increase linearly with the increasing volume fraction of the high-modulus fiber, but both the yielding displacement and ultimate displacement decrease linearly with the increasing volume fraction of the high-modulus fiber.

Improved Early-Age Cohesive Stress Response from Hybrid Blends of Micro and Macro Fibers

2021 ◽  
Vol 1046 ◽  
pp. 1-7
Author(s):  
Manjunath V. Bhogone ◽  
Kolluru V.L. Subramaniam
Keyword(s):  
Reinforced Concrete ◽  
Stress Response ◽  
Volume Fraction ◽  
Polypropylene Fiber ◽  
Fiber Reinforced Concrete ◽  
Early Age ◽  
Fiber Reinforced ◽  
Cohesive Stress ◽  
Concrete Matrix ◽  
Polypropylene Fiber Reinforced Concrete

The fracture response of macro polypropylene fiber reinforced concrete (PPFRC) and hybrid blend of macro and micro polypropylene fiber reinforced concrete (HyFRC) are evaluated at 1, 3, 7 and 28 days. There is an improvement in the early-age fracture response of HyFRC compared to PPFRC. The changing cohesive stress-crack separation relationship produced by ageing of the concrete matrix is determined from the fracture test responses. An improved early-age cohesive stress response is obtained from the hybrid blend containing micro and macro fibers. The hybrid fiber blend also has a higher tensile strength at early age when compared to an identical volume fraction of macro polypropylene fibers.

Experiment Study on the Frost Resistance of Steel Fiber Reinforced Concrete on the Microstructure

2011 ◽  
Vol 368-373 ◽  
pp. 357-360
Author(s):  
Lei Jiang ◽  
Di Tao Niu ◽  
Min Bai
Keyword(s):  
Reinforced Concrete ◽  
Frost Resistance ◽  
Steel Fiber ◽  
Volume Fraction ◽  
Fiber Reinforced Concrete ◽  
Fiber Reinforced ◽  
Nacl Solution ◽  
Steel Fiber Reinforced Concrete ◽  
Freeze Thaw ◽  
Damage Rate

Based on the fast freeze-thaw test in 3.5% NaCl solution, the frost resistance of steel fiber reinforced concrete (SFRC) was studied in this paper. On the basis of scanning electron microscope (SEM) and mercury intrusion method, the microstructure and pore structure of SFRC was analysed. The reinforced mechanism of SFRC under the cooperation of freeze-thaw and NaCl solution was discussed. The test results show that adding appropriate amount of steel fibers into concrete can reduce the pore porosity and improve the compactness of concrete. The effects of steel fiber with proper volume fraction can inhibit the peeling of the concrete and reduce its damage rate. The volume of steel fiber on the frost-resisting property of SFRC is obvious.

Flexural Performance Evaluation of Fiber-Reinforced Concrete Incorporating Multiple Macro-Synthetic Fibers

2018 ◽  
Vol 2672 (27) ◽  
pp. 1-12 ◽  
Author(s):  
Michael Dopko ◽  
Meysam Najimi ◽  
Behrouz Shafei ◽  
Xuhao Wang ◽  
Peter Taylor ◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
Residual Strength ◽  
Performance Enhancement ◽  
Construction Material ◽  
Fiber Reinforced Concrete ◽  
Fiber Reinforced ◽  
Test Beam ◽  
Synthetic Fibers ◽  
Flexural Performance ◽  
Strength And Toughness

Fiber-reinforced concrete (FRC) is a promising construction material mainly because of the crack-controlling mechanisms that discrete fibers can impart to inherently brittle concrete. Macrofibers, in particular, have been proven effective for providing post-crack ductility and toughness, while synthetic fibers are a promising solution to avoid corrosion-related durability issues. To assess the performance enhancement provided by macro-synthetic concrete fibers, this study performs flexural tests on FRC beams containing three different types of macro-synthetic fibers. The selected fibers include polypropylene (PP), polyvinyl alcohol (PVA), and alkali-resistant glass (ARG) macrofibers mixed at volume fractions of 0.5%, 1.0%, and 1.5%. Static and dynamic fresh properties are monitored using the vibrating Kelly ball (VKelly) test. Beam specimens are then placed under a third point bending configuration, as per ASTM C1609 Standard, to measure load versus mid-span deflection. Strength and toughness parameters are derived from the load–deflection data to assess the flexural performance of the FRC composite systems under consideration. The parameters of interest include first peak strength (pre-crack flexural strength) and post-crack residual strength and toughness provided by fiber addition. Of the mixtures tested, ARG fiber mixtures show the highest residual strength and toughness values, followed by PP and PVA fiber mixtures. ARG fibers produce the most workable mixtures at all fiber volumes, while PVA fibers show a tendency to encounter dispersion issues at higher volume doses. The outcome of this study is expected to facilitate the selection of fibers by giving insight into their relative contribution to fresh and hardened flexural properties of FRC.

Shear strength of reinforced concrete beams with a fiber concrete matrix

2006 ◽  
Vol 33 (6) ◽  
pp. 726-734 ◽  
Author(s):  
Fariborz Majdzadeh ◽  
Sayed Mohamad Soleimani ◽  
Nemkumar Banthia
Keyword(s):  
Shear Strength ◽  
Reinforced Concrete ◽  
Fiber Volume Fraction ◽  
Volume Fraction ◽  
Fiber Reinforcement ◽  
Shear Capacity ◽  
Fiber Reinforced Concrete ◽  
Rc Beams ◽  
Fiber Reinforced ◽  
Fiber Volume

The purpose of this study was to investigate the influence of fiber reinforcement on the shear capacity of reinforced concrete (RC) beams. Both steel and synthetic fibers at variable volume fractions were investigated. Two series of tests were performed: structural tests, where RC beams were tested to failure under an applied four-point load; and materials tests, where companion fiber-reinforced concrete (FRC) prisms were tested under direct shear to obtain material properties such as shear strength and shear toughness. FRC test results indicated an almost linear increase in the shear strength of concrete with an increase in the fiber volume fraction. Fiber reinforcement enhanced the shear load capacity and shear deformation capacity of RC beams, but 1% fiber volume fraction was seen as optimal; no benefits were noted when the fiber volume fraction was increased beyond 1%. Finally, an equation is proposed to predict the shear capacity of RC beams.Key words: shear strength, fiber-reinforced concrete, RC beam, stirrups, energy absorption capacity, steel fiber, synthetic fiber.

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