Fiber Reinforced Concrete (FRC) is a modern Technology in the field of civil engineering, this ppt gives the overall view about the FRC, Uses of FRC in simplest way.
2. Contents
Introduction
Benefits of FRC
Toughening Mechanism
Factor affecting the properties of FRC
Comparison of Mix Proportion of FRC and Plain Concrete
Type of fibers
Steel Fiber Reinforced Concrete (SFRC)
Structural behavior & Durability of SFRC
Problems with SFRC
Application Of FRC
Conclusion
References
3. Introduction to Fiber Reinforced
Concrete
Concrete containing a hydraulic cement, water ,
aggregate, and discontinuous discrete fibers is
called fiber reinforced concrete.
Fibers can be in form of steel fiber, glass fiber,
natural fiber , synthetic fiber.
4. Benefits of FRC
Main role of fibers is to bridge the cracks that develop in
concrete and increase the ductility of concrete
elements.
Improvement on Post-Cracking behavior of concrete
Imparts more resistance to Impact load
controls plastic shrinkage cracking and drying shrinkage
cracking
Lowers the permeability of concrete matrix and thus
reduce the bleeding of water
5. Toughening mechanism
Toughness is ability of a material to absorb energy and
plastically deform without fracturing.
It can also be defined as resistance to fracture of a
material when stressed.
7. Contd.
Source: P.K. Mehta and P.J.M. Monteiro, Concrete: Microstructure, Properties,
and Materials, Third Edition, Fourth Reprint 2011
8. Factors affecting the Properties of FRC
Volume of fibers
Aspect ratio of fiber
Orientation of fiber
Relative fiber matrix stiffness
9. Volume of fiber
Low volume fraction (less than 1%)
Used in slab and pavement that have large exposed
surface leading to high shrinkage cracking
Moderate volume fraction(between 1 and 2 percent)
Used in Construction method such as Shortcrete & in
Structures which requires improved capacity against
delamination, spalling & fatigue
High volume fraction(greater than 2%)
Used in making high performance fiber reinforced
composites (HPFRC)
10. Contd.
Source: P.K. Mehta and P.J.M. Monteiro, Concrete: Microstructure,
Properties, and Materials, Third Edition, Fourth Reprint 2011
11. Aspect Ratio of fiber
It is defined as ratio of length of fiber to it’s diameter
(L/d).
Increase in the aspect ratio upto 75,there is increase in
relative strength and toughness.
Beyond 75 of aspect ratio there is decrease in aspect
ratio and toughness.
12. Orientation of fibers
Aligned in the direction of load
Aligned in the direction perpendicular to load
Randomly distribution of fibers
It is observed that fibers aligned parallel to applied
load offered more tensile strength and toughness
than randomly distributed or perpendicular fibers.
13. Relative fiber matrix
Modulus of elasticity of matrix must be less than of fibers
for efficient stress transfer.
Low modulus of fibers imparts more energy absorption
while high modulus fibers imparts strength and stiffness.
Low modulus fibers e.g. Nylons and Polypropylene fibers
High modulus fibers e.g. Steel, Glass, and Carbon fibers
14. Comparison of Mix Proportion between
Plain Concrete and Fiber Reinforced
Concrete
Material Plain concrete Fiber reinforced
concrete
Cement 446 519
Water (W/C=0.45) 201 234
Fine aggregate 854 761
Coarse aggregate 682 608
Fibers (2% by volume) -- 157
The 14-days flexural strength, 8 Mpa, of the fiber reinforced was about 20% higher than that of plain
concrete.
Source: Adapted from Hanna, A.N., PCA Report RD 049.01P, Portland cement Association, Skokie, IL, 1977
15. Types of fiber used in FRC
Steel Fiber Reinforced Concrete
Polypropylene Fiber Reinforced (PFR) concrete
Glass-Fiber Reinforced Concrete
Asbestos fibers
Carbon fibers and Other Natural fibers
17. Steel Fiber Reinforced Concrete
Diameter Varying from 0.3-0.5 mm (IS:280-1976)
Length varying from 35-60 mm
Various shapes of steel fibers
18. Advantage of Steel fiber
High structural strength
Reduced crack widths and control the crack widths
tightly, thus improving durability
less steel reinforcement required
Improve ductility
Reduced crack widths and control the crack widths
tightly, thus improving durability
Improve impact– and abrasion–resistance
19. Structural Behavior of Steel Fiber
Reinforced Concrete
Effect on modulus of rupture
Effect of compressive strength
Effect on Compressive strength & tensile Strength at fire
condition i.e. at elevated temperature
20. Effect on Modulus of Rupture
Ref: Abid A. Shah, Y. Ribakov, Recent trends in steel fibered high-strength concrete, Elsevier,
Materials and Design 32 (2011), pp 4122–4151
21. Effect on Compressive Strength
Ref: Abid A. Shah, Y. Ribakov, Recent trends in steel fibered high-strength concrete, Elsevier, Materials
and Design 32 (2011), pp 4122–4151
22. Structural behavior at Elevated
Temperature
Ref: K.Srinivasa Rao, S.Rakesh kumar, A.Laxmi Narayana, Comparison of Performance of
Standard Concrete and Fibre Reinforced Standard Concrete Exposed To Elevated Temperatures,
American Journal of Engineering Research (AJER), e-ISSN: 2320-0847 p-ISSN : 2320-0936,
Volume-02, Issue-03, 2013, pp-20-26
23. Contd.
Ref: K.Srinivasa Rao, S.Rakesh kumar, A.Laxmi Narayana, Comparison of Performance of
Standard Concrete and Fibre Reinforced Standard Concrete Exposed To Elevated Temperatures,
American Journal of Engineering Research (AJER), e-ISSN: 2320-0847 p-ISSN : 2320-0936,
Volume-02, Issue-03, 2013, pp-20-26
24. Durability
Resistance against Sea water (In 3% NaCl by weight of
water)
Maximum loss in compressive strength obtained was about
3.84% for non-fibered concrete and 2.53% for fibered
concrete
Resistance against acids (containing 1% of sulfuric acid
by weight of water)
Maximum loss in compressive strength obtained was found
to be about 4.51% for non-fibered concrete and 4.42% for
fiber concrete
25. Problems with Steel Fibers
Reduces the workability;
loss of workability is proportional to volume
concentration of fibers in concrete
Higher Aspect Ratio also reduced workability
26. Application of FRC in India & Abroad
More than 400 tones of Steel Fibers have been used recently
in the construction of a road overlay for a project at Mathura
(UP).
A 3.9 km long district heating tunnel, caring heating pipelines
from a power plant on the island Amager into the center of
Copenhagen, is lined with SFC segments without any
conventional steel bar reinforcement.
steel fibers are used without rebars to carry flexural loads is a
parking garage at Heathrow Airport. It is a structure with 10
cm thick slab.
Precast fiber reinforced concrete manhole covers and frames are
being widely used in India.
27. Conclusion
The total energy absorbed in fiber as measured by the area
under the load-deflection curve is at least 10 to 40 times
higher for fiber-reinforced concrete than that of plain
concrete.
Addition of fiber to conventionally reinforced beams
increased the fatigue life and decreased the crack width
under fatigue loading.
At elevated temperature SFRC have more strength both in
compression and tension.
Cost savings of 10% - 30% over conventional concrete flooring
systems.
28. References
K.Srinivasa Rao, S.Rakesh kumar, A.Laxmi Narayana,
Comparison of Performance of Standard Concrete and Fibre
Reinforced Standard Concrete Exposed To Elevated
Temperatures, American Journal of Engineering Research
(AJER), e-ISSN: 2320-0847 p-ISSN : 2320-0936, Volume-02, Issue-
03, 2013, pp-20-26
Abid A. Shah, Y. Ribakov, Recent trends in steel fibered high-
strength concrete, Elsevier, Materials and Design 32 (2011), pp
4122–4151
ACI Committee 544. 1990. State-of-the-Art Report on Fiber
Reinforced Concrete.ACI Manual of Concrete Practice, Part
5, American Concrete Institute, Detroit,MI, 22 pp
29. Contd.
P.K. Mehta and P.J.M. Monteiro, Concrete: Microstructure,
Properties, and Materials, Third Edition, Fourth Reprint 2011, pp
502-522
ACI Committee 544, Report 544.IR-82, Concr. Int., Vol. 4, No.
5, p. 11, 1982
Hanna, A.N., PCA Report RD 049.01P, Portland Cement
Association, Skokie, IL, 1977
Ezio Cadoni ,Alberto Meda ,Giovanni A. Plizzari, Tensile
behaviour of FRC under high strain-rate,RILEM, Materials and
Structures (2009) 42:1283–1294
Marco di Prisco, Giovanni Plizzari, Lucie Vandewalle, Fiber
Reinforced Concrete: New Design Prespectives, RILEM,
Materials and Structures (2009) 42:1261-1281
