The document details fiber reinforced concrete (FRC), including its historical use, types of fibers, mechanical properties, structural behavior, advantages, disadvantages, and applications. It explains how fibers enhance concrete's toughness, reduce cracking, and increase strength and durability. The paper concludes that FRC demonstrates significantly higher energy absorption and fatigue life compared to plain concrete.

1. FIBRE REINFORCED CONCRETE (F.R.C)
 PREPARED BY
MOHAMMAD ABDUL ZUBAIR
160423741008
M.E 1ST
SEMESTER
STRUCTURAL ENGINEERING

2. CONTENTS
🠶 History.
🠶 Introduction.
🠶 Why Fibers are used?
🠶 Toughening Mechanism.
🠶 Type of fibers.
🠶 Mechanical properties of FRC.
🠶 Structural behavior of FRC.
🠶 Factors affecting properties of FRC.
🠶 Advantages and Disadvantages of FRC.
🠶 Applications of FRC.
 CONCLUSION
 REFERENCES

3. 🠶 The use of fibers goes back at least 3500 years,
when straw was used to reinforce sun-baked bricks
in Mesopotamia.
🠶 Horsehair was used in mortar and straw in mud
bricks.
🠶 Abestos fibers were used in concrete in the early
1900.
🠶 In the 1950s, the concept of composite materials
came
into picture.
🠶 Steel , Glass and synthetic fibers have been used to
improve the properties of concrete for the past 30 or
40 years.
HISTORY

4. INTRODUCTION
🠶 Concrete containing cement, water , aggregate,
and discontinuous, uniformly dispersed or discrete
fibers is called fiber reinforced concrete.
🠶 It is a composite obtained by adding a single type or
a blend of fibers to the conventional concrete mix.
🠶 Fibers can be in form of steel fibers, glass fibers,
natural
fibers , synthetic fibers, etc.

5. WHY FIBRES ARE
USED?
🠶 Main role of fibers is to bridge the cracks that develop in
concrete and increase the ductility of concrete elements.
🠶 There is considerable improvement in the post-cracking
behavior of concrete containing fibers due to both
plastic shrinkage and drying shrinkage.
🠶 They also reduce the permeability of concrete and
thus reduce bleeding of water.
🠶 Some types of fibers produce greaterabrasion and
shatter
resistance in concrete.
🠶 Imparts more resistance to Impact load.

6. WHY ?
 Concrete:
 Brittle
 Weak In Tension

7. MECHANISM OF TOUGHENING
🠶 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.

8. CONTD.

9. COND.
Source: P
.K. Mehta and P.J.M. Monteiro, Concrete: Microstructure,
Properties, and Materials, Third Edition, Fourth Reprint 2011

10. TYPES OF FIBERS :
Steel
fibers
Glass
fibers

11. Carbon
Fibers
CELLULOSE FIBERS

12. SYNTHETIC
FIBERS:
Nylon
Fibers
Polypropylene
Fibers

13. NATURAL
FIBERS:
Coi
r
Hay

14. STEEL
FIBERS
🠶 Aspect ratios of 30 to 250.
🠶 Diameters vary from 0.25 mm to 0.75 mm.
🠶 High structural strength.
🠶 Reduced crack widths and control the crack widths tightly,
thus
improving durability.
🠶 Improve impact and abrasion resistance.
🠶 Used in precast and structural applications, highway and
airport pavements, refractory and canal linings, industrial
flooring, bridge decks, etc.

15. GLASS
FIBERS
🠶 High tensile strength, 1020 to 4080 N/mm2
🠶 Generally, fibers of length 25mm are used.
🠶 Improvement in impact strength.
🠶 Increased flexural strength, ductility and resistance to
thermal shock.
🠶 Used in formwork, swimming pools, ducts and roofs,
sewer lining etc.

16. SYNTHETIC
FIBERS
🠶 Man- made fibers from petrochemical and textile
industries.
🠶 Cheap, abundantly available.
🠶 High chemical resistance.
🠶 High melting point.
🠶 Low modulus of elasticity.
🠶 It’s types are acrylic, aramid, carbon, nylon, polyester,
polyethylene, polypropylene, etc.
🠶 Applications in cladding panels and shotcrete.

17. NATURAL
FIBERS
🠶 Obtained at low cost and low level of energy using
local
manpower and technology.
🠶 Jute, coir and bamboo are examples.
🠶 They may undergo organic decay.
🠶 Low modulus of elasticity, high impact strength.

18. Types of
Fibers
Types Tensile Strength Young's Modulus Ultimate
Elongation
Specific Gravity
( Mpa ) ( 103 Mpa ) ( % )
Steel 275 - 2758 200 0.5 - 35 2.50
Glass 1034 - 3792 69 1.5 - 3.5 3.20
Asbestos 551 - 965 89 - 138 0.60 1.50
Rayon 413 - 520 6.89 10 - 25 1.50
Cotton 413 - 689 4.82 3 -10 1.10
Nylon 858 - 827 4.13 16 - 20 0.50
Polypropylene 551 - 758 3.45 24 1.10
Acrylic 206 - 413 2.06 25 - 45 0.90

19. MECHANICAL
PROPERTIES OF FRC
🠶 Compressive Strength
The presence of fibers may alter the failure mode of
cylinders, but the fiber effect will be minor on the
improvement of compressive strength values (0 to 15
percent).
🠶 Modulus of Elasticity
Modulus of elasticity of FRC increases slightly with an increase
in the fibers content. It was found that for each 1 percent
increase in fiber content by volume, there is an increase of 3
percent in the modulus of elasticity.
🠶 Flexure
The flexural strength was reported to be increased by 2.5
times using 4 percent fibers.

20. 🠶 Splitting Tensile Strength
The presence of 3 percent fiber by volume was reported to
increase the splitting tensile strength of mortar about 2.5
times that of the unreinforced one.
🠶 Toughness
For FRC, toughness is about 10 to 40 times that of plain
concrete.
🠶 Fatigue Strength
The addition of fibers increases fatigue strength of about
90 percent.
🠶 Impact Resistance
The impact strength for fibrous concrete is generally 5 to
10
times that of plain concrete depending on the volume of

21. STRUCTURAL
BEHAVIOUR OF FRC
🠶 Flexure
The use of fibers in reinforced concrete flexure members
increases ductility, tensile strength, moment capacity, and
stiffness. The fibers improve crack control and preserve post
cracking structural integrity of members.
🠶 Torsion
The use of fibers eliminate the sudden failure characteristic of
plain concrete beams. It increases stiffness, torsional strength,
ductility, rotational capacity, and the number of cracks with less
crack width.
🠶 High Strength Concrete
Fibers increases the ductility of high strength concrete.
Fiber addition will help in controlling cracks and
deflections.

22. 🠶 Shear
Addition of fibers increases shear capacity of reinforced
concrete beams up to 100 percent. Addition of randomly
distributed fibers increases shear-friction strength and ultimate
strength.
🠶 Column
The increase of fiber content slightly increases the ductility of
axially loaded specimen. The use of fibers helps in reducing
the explosive type failure for columns.
🠶 Cracking and Deflection
T
ests have shown that fiber reinforcement effectively controls
cracking and deflection, in addition to strength improvement.
In conventionally reinforced concrete beams, fiber addition
increases stiffness, and reduces deflection.

23. FACTORS AFFECTING THE
PROPERTIES OF FRC
🠶 Volume of fibers
🠶 Aspect ratio of fiber
🠶 Orientation of fiber
🠶 Relative fiber matrix
stiffness

24. 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.

25. 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.
Type
of
concret
e
Aspect ratio Relativ
e
streng
th
Relative
toughne
ss
Plain concrete
with
randomly
Dispersed
fibers
0 1.0 1.0
25 1.50 2.0
50 1.60 8.0
75 1.70 10.50
100 1.50 8.50

26. 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.

27. L
oLaoda
ddDiirr
eecc
tti
oino
n
Paralle
l
Perpendicula
r
Random

28. 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.

29. ADVANTAGES OF FRC
🠶 High modulus of elasticity for effective long-
term reinforcement, even in the hardened
concrete.
🠶 Does not rust nor corrode and requires no
minimum cover.
🠶 Ideal aspect ratio (i.e. relationship between Fiber
diameter and length) which makes them excellent for
early-age performance.
🠶 Easily placed, Cast, Sprayed and less labour intensive
than
placing rebar.
🠶 Greater retained toughness in conventional concrete
mixes.
🠶 Higher flexural strength, depending on addition rate.

30. DISADVANTAGES
OF FRC
🠶 Greater reduction of workability.
🠶 High cost of materials.
🠶 Generally fibers do not increase the flexural strength
of concrete, and so cannot replace moment
resisting or structural steel reinforcement.

31. APPLICATIONS OF FRC
🠶 Runway, Aircraft Parking, and Pavements.
For the same wheel load FRC slabs could be about one half
the thickness of plain concrete slab. FRC pavements offers
good resistance even in severe and mild environments.
It can be used in runways, taxiways, aprons, seawalls, dock
areas, parking and loading ramps.
🠶 Tunnel Lining and Slope Stabilization
Steel fiber reinforced concrete are being used to line
underground openings and rock slope stabilization. It
eliminates the need for mesh reinforcement and scaffolding.
🠶 Dams and Hydraulic Structure
FRC is being used for the construction and repair of dams and
other hydraulic structures to provide resistance to cavitation
and severe erosion caused by the impact of large debris.

32. 🠶 Thin Shell, Walls, Pipes, and Manholes
Fibrous concrete permits the use of thinner flat and
curved structural elements. Steel fibrous shortcrete is
used in the construction of hemispherical domes.
🠶 Agriculture
It is used in animal storage structures, walls, silos, paving,
etc.
🠶 Precast Concrete and Products
It is used in architectural panels, tilt-up construction,
walls, fencing, septic tanks, grease trap structures,
vaults and sculptures.

33. 🠶 Commercial
It is used for exterior and interior floors, slabs and parking
areas, roadways, etc.
🠶 Warehouse / Industrial
It is used in light to heavy duty loaded floors.
🠶 Residential
It includes application in driveways, sidewalks, pool
construction,
basements, colored concrete, foundations, drainage, etc.

34. Fiber Reinforced
Concrete
NORMAL REINFORCED
CONCRETE
• High Durability
• Protect steel from
Corrosion
• Lighter materials
• More expensive
• With the same volume,
the strength is greater
• Less workability
• Lower Durability
• Steel potential to corrosion
• Heavier material
• Economical
• With the same volume,
the strength is less
• High workability as
compared to FRC.

35. APPLICATION OF FRC IN INDIA
& ABROAD
🠶 More than 400 tones of Steel Fibers have been used in the
construction of a road overlay for a project at Mathura
(UP).
🠶 A 4 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 at
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.

36. Pavement with steel fibre reinforced
concrete

37. 🠶 INCREASE IN COMPRESSIVE STRENGTH
OF CONCRETE:
⦿ Specimens without any
fibers after
compression test
 Specimens with
fibers after
compression test

38. 🠶 INCREASE IN TENSILE STRENGTH
OF CONCRETE:
⦿ Specimens without
any fibers after split
tensile test.
 Specimens with
fibers
after slip tensile test.

39. 🠶 INCREASE IN IMPACT STRENGTH
OF CONCRETE:
⦿ Specimens without any
fibers after
compression test
 Specimens with
fibers after
compression test

40. 🠶 INCREASE IN SHEAR STRENGTH
OF CONCRETE:
⦿ Specimens without
any
fibers after shear test.
 Specimens with
fibers after shear
test.

41. GFRC PROJECT
AT TRILLIUM
BUILDING
WOODLAND
HILLS,
CALIFORNIA

42. FOOTBRI
DGE IN
FREDRIK
STAD,
NORWAY

43. SFRC USED AT
TEHRI DAM,
UTTARAKHAND

44. 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.

45. 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