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Polypropylene fiber reinforced concrete an overview

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Polypropylene Fiber Reinforced Concrete : An Overview
The capability of durable structure to resist weathering action, chemical attack, abrasion and other degradation processes during its
service life with the minimal maintenance is equally important as the capacity of a structure to resist the loads applied on it. Although
concrete offers many advantages regarding mechanical characteristics and economic aspects of the construction, the brittle behavior
of the material remains a larger handicap for the seismic and other applications where ퟢ�exible behaviour is essentially required.
Recently, however the development of polypropylene 韛�ber-reinforced concrete (PFRC) has provided a technical basis for improving these

de韛�ciencies. This paper presents an overview of the effect of polypropylene (PP) 韛�bers on various properties of concrete in fresh and
hardened state such as compressive strength, tensile strength, ퟢ�exural strength, workability, bond strength, fracture properties, creep
strain, impact and chloride penetration. The role of 韛�bers in crack prevention has also been discussed.
S. K. Singh, Scientist, Structural Engineering Division, Central Building Research Institute, Roorkee & Honorary Secretary Institute of
Engineers, Roorkee

Introduction
Ceramics were the 韛�rst engineering materials known to mankind and they still constitute the most used materials in terms of weight [1,
2]. Hydraulic cements and cement-based composites including concretes are the main ceramic-based materials. Concrete offers many
advantages in the application due to its improved mechanical characteristics, low permeability and higher resistance against chemical
and mechanical attacks. Although concrete behavior is governed signi韛�cantly by its compressive strength, the tensile strength is
important with respect to the appearance and durability of concrete. The tensile strength of concrete is relatively much lower. Therefore,
韛�bers are generally introduced to enhance its ퟢ�exural tensile strength, crack arresting system and post cracking ductile behaviour of
basic matrix.
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Concrete modi韛�cation by using polymeric materials has been studied for the past four decades [3]. In general, the reinforcement of
brittle building materials with 韛�bers has been known from ancient period such as putting straw into the mud for housing walls or
reinforcing mortar using animal hair etc. Many materials like jute, bamboo, coconut, rice husk, cane bagasse, and sawdust as well as
synthetic materials such as polyvinyl alcohol, polypropylene (PP), polyethylene, polyamides etc. have also been used for reinforcing the
concrete [4,5,6,7,8]. Research and development into new 韛�ber reinforced concrete is going on today as well.
Polypropylene 韛�bers were 韛�rst suggested as an admixture to concrete in 1965 for the construction of blast resistant buildings for the US
Corps of Engineers. The 韛�ber has subsequently been improved further and at present it is used either as short discontinuous 韛�brillated
material for production of 韛�ber reinforced concrete or a continuous mat for production of thin sheet components. Since then the use of
these 韛�bers has increased tremendously in construction of structures because addition of 韛�bers in concrete improves the toughness,
ퟢ�exural strength, tensile strength and impact strength as well as failure mode of concrete. Polypropylene twine is cheap, abundantly
available, and like all manmade 韛�bers of a consistent quality.

Properties of Polypropylene Fibers
The raw material of polypropylene is derived from monomeric C3H6 which is purely hydrocarbon. Its mode of polymerization, its high
molecular weight and the way it is processed into 韛�bers combine to give polypropylene 韛�bers very useful properties as explained below
[9]:
There is a sterically regular atomic arrangement in the polymer molecule and high crystallinity. Due to regular structure, it is known as
isotactic polypropylene.
Chemical inertness makes the 韛�bers resistant to most chemicals. Any chemical that will not attack the concrete constituents will
have no effect on the 韛�ber either. On contact with more aggressive chemicals, the concrete will always deteriorate 韛�rst.
The hydrophobic surface not being wet by cement paste helps to prevent chopped 韛�bers from balling effect during mixing like other
韛�bers.
The water demand is nil for polypropylene 韛�bers.
The orientation leaves the 韛�lm weak in the lateral direction which facilitates 韛�brillations. The cement matrix can therefore penetrate
in the mesh structure between the individual 韛�brils and create a mechanical bond between matrix and 韛�ber.

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The 韛�bers are manufactured either by the pulling wire procedure with circular cross section or
by extruding the plastic 韛�lm with rectangular cross-section. They appear either as 韛�brillated
bundles, mono 韛�lament or micro韛�laments as shown in Fig. 1 & 2. The properties of these three
types of PP 韛�bers are given in Table 1 [10]. The 韛�brillated polypropylene 韛�bers are formed by
expansion of a plastic 韛�lm, which is separated into strips and then slit. The 韛�ber bundles are
Figure 1: mono韛�lament 韛�ber
Figure 2: Fibrillated 韛�ber
cut into speci韛�ed lengths and 韛�brillated. In mono韛�lament 韛�bers, the addition of buttons at the
ends of the 韛�ber increases the pull out load. Further, the maximum load and stress transfer could also be achieved by twisting 韛�bers
[11].

Role of Fibers
Cracks play an important role as they change concrete structures into permeable elements and consequently with a high risk of
corrosion. Cracks not only reduce the quality of concrete and make it aesthetically unacceptable but also make structures out of service.
If these cracks do not exceed a certain width, they are neither harmful to a structure nor to its serviceability. Therefore, it is important to
reduce the crack width and this can be achieved by adding polypropylene 韛�bers to concrete [13]. The bridging of cracks by the addition
of PP 韛�bers has been shown in Fig 3.

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Thus addition of 韛�bers in cement concrete matrix bridges these cracks and restrains them from further opening. In order to achieve

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more deퟢ�ection in the beam, additional forces and energies are required to pull out or fracture the 韛�bres. This process, apart from
preserving the integrity of concrete, improves the load-carrying capacity of structural member beyond cracking. This improvement
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creates a long post-peak descending portion in the load deퟢ�ection curve as shown in Fig 4 [12]. Reinforcing steel bars in concrete have
the same bene韛�cial
because they actSubscription
as long continuous
韛�bres. Short discontinuous
韛�bres
have
advantage, however, of being
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uniformly mixed and dispersed throughout the concrete.
The major reasons for crack formation are Plastic shrinkage, Plastic settlement, Freeze thaw damage, Fire damage etc.
Plastic shrinkage: It occurs when surface water evaporates before the bleed water reaches the surface. Polypropylene 韛�bers reduce the
plastic shrinkage crack area due to their ퟢ�exibility and ability to conform to form. The addition of 0.1% by volume of 韛�bers is found
effective in reducing the extent of cracking by a factor of 5-10. The extent of crack reduction is proportional to the 韛�ber content in the
concrete.
Table 1: Properties of various types of polypropylene 韛�bers
Length Diameter
(mm)
(mm)

Tensile
strength
(MPa)

Modulus of
elasticity (GPa)

mono韛�lament 30-50 0.30-0.35

547-658

3.50-7.50

91

0.9

micro韛�lament 12-20 0.05-0.20

330-414

3.70-5.50

225

0.91

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500-750

5.00-10.00

58

0.95

We have 2142 guests and
no members online

Fiber type

Fibrillated

19-40 0.20-0.30

Figure 3: Bridging of crack using Polypropylene 韛�bers

Speci韛�c
surface
(m2/kg)

Density
(kg/cm3)

Figure 4: Typical load-elongation response in tension of FRC.

Plastic settlement: High rate of bleeding and settlement combined with restraint to settlement (e.g. by reinforcing bars) leads to
settlement cracking. In case of PFRC, 韛�bers are uniformly distributed. Fibers are ퟢ�exible so they cause negligible restraint to settlement
of aggregates.
Freeze thaw damage: Small addition of polypropylene 韛�bers in concrete reduces the ퟢ�ow of water through the concrete matrix by
preventing the transmission of water through the normal modes of ingress, e.g. capillaries, pore structure, etc. The implications of these


qualities in concrete with polypropylene 韛�ber additions are that cement hydration will be improved, separation of aggregate will be
reduced and the ퟢ�ow of water through concrete that causes deterioration from freeze/ thaw action and rebar corrosion will be reduced,
creating an environment in which enhanced durability may take place.

Spalling of homogenous structure of Concrete due to insuퟵ�cient capillary
pores

Developed explosion channels due to melting of PP 韛�bers

Figure 5: Flowing out of steam pressure through the melted PP 韛�bers in the case of 韛�re

Fire damage: Heat penetrates the concrete resulting in desorption of moisture in outer layer. Moisture vapors ퟢ�ow back towards the cold
interior and are reabsorbed into voids. Water and vapor accumulate in the interior thereby increasing the vapor pressure rapidly causing
cracks and spalling in the concrete. In case of PFRC, the 韛�bers melt at 160oC creating voids in the concrete. The vapor pressure is
released in newly formed voids and explosive spalling is signi韛�cantly reduced as shown in 韛�g 5[14].

Properties of PP Fiber Reinforced Concrete
Before mixing the concrete, the 韛�ber length, amount and design mix variables are adjusted to prevent the 韛�bers from balling. Good FRC
mixes usually contain a high mortar volume as compared to conventional concrete mixes. The aspect ratio for the 韛�bers are usually
restricted between 100 and 200 since 韛�bers which are too long tend to "ball" in the mix and create workability problems. As a rule, 韛�bers
are generally randomly distributed in the concrete; however, placing of concrete should be in such a manner that the 韛�bers become
aligned in the direction of applied stress which will result in even greater tensile and ퟢ�exural strengths. There should be suퟵ�cient
compaction so that the fresh concrete ퟢ�ows satisfactorily and the PP 韛�bers are uniformly dispersed in the mixture. The 韛�bers should not
ퟢ�oat to the surface nor sink to the bottom in the fresh concrete. Chemical admixtures are added to 韛�ber-reinforced concrete mixes
primarily to increase the workability of the mix. Air-entraining agents and water-reducing admixtu- res are usually added to mixes with a
韛�ne aggregate content of 50% or more. Superplasticizers, when added to 韛�ber-reinforced concrete, can lower water: cement ratios, and
improve the strength, volumetric stability and handling characteristics of the wet mix. The properties of PFRC with various 韛�ber volume
% are shown in Table 2.
Table 2 Mechanical Properties of Polypropylene Fiber Reinforced Concrete
No

Concrete mix

Vf %

Fibers

fcu

ft

fs

Slump Ref.

(MPa) (MPa) (MPa) (mm)
w/c

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Cement

CA

(kg/m3)

FA

(kg/m3) (kg/m3)

Admixture

Specimen

Type

shape

Super

l/d

Cylinder,

Fibrillated
17.2 1.08 4.5
0 0.10
100 –
(20mm long & 69
14.1 1.72 2.5
[15]
0.30
120
Prism
0.29mm dia)
12.6 1.34 3.0
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1000
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1. 0.49 390 (OPC)
640
plasticizer
Cubes &
(10mm)

(Fosroc 430)
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2. 0.45 360 (OPC)

3. 0.45 360 (OPC)

4. 0.48 418 (OPC)

5. 0.40

6. 0.50

7. 0.44

8. 0.39

9. 0.30

10. 0.30

11. 0.36

12. 0.40

1100
(20mm)

1100
(20mm)
724
(25mm)

372 OPC + 1140
28 SF
(20mm)
383

1162

(PPC)

(20mm)

430

1154

(PPC)

(20mm)

498

1136

(PPC)

(20mm)

567
(OPC)
567
(OPC)

415

-

Prism

647

-

Prism

(19mm long & 396
0.048mm dia)
Mono 韛�lament
(30mm long &

-

Cylinder

750

Superplasticizer

Prism

572

-

540

-

Mono 韛�lament

0.082
0.128
1.0

55

0.55 mm dia)
998

0.045

1.2
1.4

56

0 1.0
1.5

Mono 韛�lament 200 0 0.5

Cylinder,
Cubes &

Graded
Fibrillated

Prism

(12mm ~ 24mm)

Cylinder,
Cubes &

Graded
Fibrillated

Prism

12mm ~ 24mm)

NIL

Superplasticizer

--

2.24

4.01

2.33

3.76

2.40
2.43

4.01
4.22

2.50

5.36

-

2.68

5.47

-

2.70

5.51

35.03 2.23
35.42 3.21
56.10 4.10
56.10 4.40

5.23
5.47

4.88

5.65

4.95

6.35

41.22 3.72

5.35

46.15 3.89

1120
(20mm)

740

Super
plasticizer

-

(6 mm long & 100

0 0.25

630

713

Cylinder

81.60 4.40

Fibrillated(30mm
Superplasticizer
0.25 71.90 5.40
1050
Cylinder long& 0.06mm 500
(Paric FP300U)
0.50 59.40 4.70
di)

(20mm)

5.99
6.12
6.29
5.56

Graded
0 0.1
50.67 4.88 5.70
Cubes &
Fibrillated
NR 0.2
55.33 5.09 6. 40
Prism 12mm ~ 24mm)
0.3
57.11 5.52 6.84
Fibrillated
0.06 mm dia)

Cylinder,
Cubes &
Prism
Cubes &
Cylinder

-

0.50

-

60.80 4.10
60.00 4.30

Fibrillated

126

--

--

38.20

-

4.80

-

5.10
5.40

0

38.0

4.00

0.1

34.5

4.40

0.2

42.0

5.00

0.3

41.4

5.15

0 0.10
Mono 韛�lament 700
37.60
0.10
Mesh Type
150
37.20

-

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[10]

-

[10]

38

[16]

7

4.42

1050

(Paric FP300U)

--5.21
5.61

3.54

0 0.1
49.78 4.53
NR 0.2
50.22 4.67
0.3
52.00 4.75

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--

102

30.74 3.21

35.23
0 0.1
39.50
NR 0.2
41.00
0.3
48.00

Cylinder,
503

--

630

314OPC+56 1268
Fly ash

0

Micro 韛�lament
647

--

100
[29]
80
--

[25]

--

[25]

-400600
400600
73 55
45

[25]

[23]

[23]

[30]

20
20
15

[28]

10

Where: Vf - volume fraction of 韛�ber; fcu - compressive strength; ft - tensile strength and fs - ퟢ�exural strength, SF- Silica fume

Polypropylene 韛�bers are used in two different ways to reinforce cementitious matrices. One application is in thin sheet components in
which polypropylene provides the primary reinforcement. Its volume content is relatively high exceeding 5%, in order to obtain both
strengthening and toughening. In other application the volume content of the polypropylene is low, less than 0.3% by volume, and it is
intended to act mainly as secondary reinforcement for crack control, but not for structural load bearing applications [11]. The
performance and inퟢ�uence of the polypropylene 韛�bers in the fresh and hardened concrete is different and therefore these two topics are
treated separately.
Effects on Fresh Concrete
The main parameter, which is often used to determine the workability of fresh concrete, is the slump test. The slump value depends
mainly on the water absorption and porosity of the aggregates, water content in the mixture, amount of the aggregate and 韛�ne material
in the mixture, shape of the aggregates and surface characteristics of the constituents in the mixture. The slump values decrease
signi韛�cantly with the addition of polypropylene 韛�bers as shown in Table 3. The concrete mixture becomes rather clingy resulting in
increasing of the adhesion and cohesiveness of fresh concrete. During mixing the movement of aggregates shears the 韛�brillated 韛�bers
apart, so that they open into a network of linked 韛�ber 韛�laments and individual 韛�bers. These 韛�bers anchor mechanically to the cement
paste because of their large speci韛�c surface area. The concrete mixture with polypropylene 韛�bers results in the fewer rate of bleeding
and segregation as compared to plain concrete. This is because the 韛�bers hold the concrete together and thus slow down the
settlement of aggregates. Due to its high tensile and pull-out strength, the PP 韛�bers even reduce the early plastic shrinkage cracking by
enhancing the tensile capacity of fresh concrete to resist the tensile stresses caused by the typical volume changes. The 韛�bers also
distribute these tensile stresses more evenly throughout the concrete. As the plastic shrinkage cracking decreases, the number of
cracks in the concrete under loading is reduced, due to decrease in cracks from the existing shrinkage cracks. If shrinkage cracks are
still formed, the 韛�bers bridge these cracks, reducing at the same time their length and width. Moreover, as the rate of bleeding
decreases, the use of polypropylene 韛�bers may accelerate the time to initial and 韛�nal set of the concrete as this led to a slower rate of
drying in the concrete [14].
Table 3: Effect of polypropylene 韛�bers on concrete slump [18]
(mm)
Initial slump
(mm)

Final slump
(mm)

Fiber length
(mm)

90
130
170
127
1245
114

76
70
120
48
53
64

51
51
30
51
51
19

Effects on Hardened Concrete
The addition of polypropylene 韛�bres in the concrete did not signi韛�cantly affect the compressive strength and the modulus of elasticity
but they do increase the tensile strength. Splitting tensile strength of PFRC approx ranges from 9% to 13% of its compressive strength.
Addition of PP 韛�bers in concrete increases the splitting tensile strength by approx 20% to 50% [16].
Compressive strength: The compression strength of concrete is a vital parameter as it decides the other parameters like tension, ퟢ�exure
etc. The effect of polypropylene 韛�ber on the compressive strength of concrete has been discussed in many literatures and observed that

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polypropylene 韛�ber either decreases or increases the compressive strength of concrete, but overall effect is negligible in many cases. In
fact, the effect of a low volume of polypropylene 韛�ber on the compressive strength of concrete may be concealed by the experimental
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Flexural tensile strength: The ퟢ�exural tensile strength increases with increase in volume fraction of 韛�ber. It is also observed that there
was increase in strength for with the increase in aspect ratio of 韛�bre.
Bond strength: It is necessary that there should be a good bond between the 韛�ber and the
matrix. If the critical 韛�ber volume for strengthening has been reached then it is possible to
achieve multiple cracking. This is a desirable situation because it changes a basically brittle
material with a single fracture surface to fracture into a pseudo ductile material which can
absorb transient minor overload and shocks with little visible damage. So the aim is to
produce large number of multiple cracks at as close spacing as possible so that the crack
widths are very small, almost invisible to naked eye so that the rate at which aggressive
materials can penetrate the matrix is reduced. High bond strength helps to give close crack
spacing but it is also essential that the 韛�bers should give suퟵ�cient ductility to absorb impacts.
But in terms of physiochemical adhesion there is no bond between the 韛�ber and the cement
gel. The use of chopped and twisted 韛�brillated polypropylene 韛�bers with their open structure
has partially remedied the lack of interfacial adhesion by making use of wedge action at the
slightly open 韛�ber ends and also by mechanical bonding through 韛�brillation. The general pull
out loads of twisted 韛�brillated 韛�bers [20, 21] may range from 300-500N for commonly used
staples but the accurate calculation of bond strength is complicated by a lack of knowledge of
the surface area of 韛�ber in contact with the paste. It is observed that in damaged products and
in broken specimens, usually 韛�ber breaks instead of 韛�ber pull out [9].

Figure 6: Fracture shape of
plain concrete

Figure 7: Fracture shape of
PFR concrete

Fracture Properties: The failure behaviour of high-strength concretes is effectively improved by the use of 韛�bers. The typical shear bond
rupture due to strain localization could be avoided (韛�g. 6). Instead of this, a large number of the longitudinal cracking, which was
predominantly oriented in the direction parallel or sub-parallel to the external compressive stresses, was formed at the entire concrete
specimens as shown in 韛�g7.
Creep and shrinkage properties of concrete: Fibers reduce creep strain, which is de韛�ned as the time-dependent deformation of concrete
under a constant stress. Compressive creep values, however, may be only 10 to 20% of those for normal concrete. Shrinkage of
concrete, which is caused by the withdrawal of water from concrete during drying, is also reduced by 韛�bers. The shrinkage, creep and
total time dependent deformation of various PFRC mixes along with non 韛�brous concrete mix are presented in 韛�g 8[15]. The reduction in
shrinkage due to the presence of 韛�bers is expected from number of viewpoints. First, the 韛�bers do not exhibit any shrinkage, thus
reducing overall shrinkage of the mix. In addition the 韛�bers have a role in retaining the water in the concrete mix upto a certain limit
which helps to delay the shrinkage. Therefore addition of 韛�bers to the concrete mixes is always advantageous in reducing shrinkage
deformation.

Figure 8: Time dependent deformation of polypropylene 韛�bers

Figure10: Effect of polypropylene 韛�bers on impact resistance of
concrete

Flexural impact properties: The number of blows required to develop the 韛�rst visible crack on the beam’s lower surface is de韛�ned as the
initial-crack impact number (Ncr). Failure impact number Nf is de韛�ned as the number at which one main macro-crack develops from
bottom to top of the beam. Impact ductility index is de韛�ned as the ratio of failure impact number to initial crack impact number, which
can be used to present the ퟢ�exural impact ductility.
J=Nf / Ncr
where J is impact ductility index, which for plain concrete is 1. The ퟢ�exural impact test results are shown in table 6 by researcher[10].
The impact resistance for concretes with various volume fractions of 韛�brillated polypropylene 韛�bers has been shown in 韛�gure 10. The
results indicate that signi韛�cant improvement in impact resistance of concrete can be achieved with relatively low volume fraction of
polypropylene 韛�bers.
Table 6: Impact properties of 韛�ber reinforced concrete
Type of mix

Vf %

Average Impact number

Average failure
Impact number

Impact ductility index

Control

0

25.8

26.8

1.04

34.7
28.6
38.1

46.5
30.4
40.1

1.34
1.06
1.05

68.9
70.7
62.8

224.2
712.7
831

3.26
10.08
13.23

0.05
Micro韛�lament 0.095
0.14
Mono韛�lament

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1
1.2
1.4

Chloride penetration: Besides improved mechanical properties due to inclusion of 韛�ber, chloride penetration is also reduced
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substantially by the presence of 韛�bers depending upon its orientation. Antoni [17] studied the effect of chloride penetration and found
that the effectAbout
is insigni韛�cant
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as compare
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chloride movement into concrete is reduced signi韛�cantly by the presence of 韛�ber as the interfacial transition zone in the direction
perpendicular to the chloride penetration whereas 韛�ber provides easier path for the chloride to migrate in direction along the 韛�ber.

Obstacles in Use of PFRC
Although PP 韛�bers are gaining wide applications in many 韛�elds, there is still need for improvement in some properties. A major 韛�re will
leave the concrete with additional porosity equal to the volume of 韛�bers incorporated in the concrete usually in the order of 0.3 to 1.5%
by volumetric fraction. In respect of mono韛�lament 韛�bers, the poor bond between 韛�ber and matrix results in a low pull out strength. The
PP 韛�bers are also attacked by sunlight and oxygen, however surrounding concrete in PFRC protects the 韛�bers so well that this
shortcoming is not signi韛�cant. Further, sometimes the 韛�bers function as initiator of the micro cracking because of their low modulus of
elasticity as compared to the cement matrix. Thus mechanical bond with the cement matrix is also low. The 韛�bers cause the
enhancement of the pores volume of concrete by creating more micro-defects in the cement matrix.

Conclusion
Innovations in engineering design and construction, which often call for new building materials, have made polypropylene 韛�berreinforced concrete applications. In the past several years, an increasing number of constructions have been taken place with concrete
containing polypropylene 韛�bres such as foundation piles, prestressed piles, piers, highways, industrial ퟢ�oors, bridge decks, facing
panels, ퟢ�otation units for walkways, heavyweight coatings for underwater pipe etc. This has also been used for controlling shrinkage &
temperature cracking.
Due to enhance performances and effective cost-bene韛�t ratio, the use of polypropylene 韛�bers is often recommended for concrete
structures recently. PFRC is easy to place, compact, 韛�nish, pump and it reduces the rebound effect in sprayed concrete applications by
increasing cohesiveness of wet concrete. Being wholly synthetic there is no corrosion risk. PFRC shows improved impact resistance as
compared to conventionally reinforced brittle concrete. The use of PFRC provides a safer working environment and improves abrasion
resistance in concrete ퟢ�oors by controlling the bleeding while the concrete is in plastic stage. The possibility of increased tensile
strength and impact resistance offers potential reductions in the weight and thickness of structural components and should also reduce
the damage resulting from shipping and handling.
Acknowledgment
The author wishes to express his sincere thanks to Ms Sonal Dhanvijay & Ms Vedanti Ganwir of Visvesvaraya National Institute of
Technology, Nagpur for their valuable help in preparing this paper.

References
Saenz, A., Rivera, E., Brostow, W. and Castan˜o, V.M., "J. Mater," (Ed.), Vol..21, No.267 (1999).
Castan˜o, V. M. and Rodriguez, J. R., "Performance of Plastics" Ch 24, Brostow, W., ed., Hanser, Munich-Cincinnati (2000).
Dodson, V., "Concrete and Mixtures" Van Nostrand Reinhold: Structural Engineering Series, New York (1989).
Sheldon, R. R.,"Composite Polymer Materials" Applied Science Publishers, London (1982).
Ramaswamy, H. S., Ahuja, B. M. and Krishnamoorthy, S., "J. Mex. Inst. Cement Concrete" Vol. 22,No. 161 (1984).


Ramaswamy, H. S., Ahuja, B. M. and Krishnamoorthy, S., "J. Mex. Inst. Cement Concrete" Vol. 22,No. 161 (1984).
Jindal, C. V., " J. Composite Materials," Vol.20, No.265 (1986).
Beaudoin, J. J., "Handbook of Fibre Reinforced Concrete" Noyes Publications, New Jersey (1990).
Colling, J., " J. Mex. Inst. Cement Concrete" Vol. 19, No. 127 (1981).
Hananth, D. J., "Fiber Cements and Fiber Concretes" A Wiley-Inter science Publication, John Wiley and Sons, Ltd pp 81-98.
Deng, Z., and Li, J., "Tension and Impact Behaviours of New Type Fibre Reinforced Concrete." Computers and Concrete, Vol. 4, No. 1
(2007) pp. 19-32.
Bentur, A. and Mindess, S., "Fiber Reinforced Cementitious Composites," Elsevier Science Publishers Ltd. Ch 10, pp 310-330.
"High performance concrete" A state of art report (1989-1994).
Bruce, P., "Effective Use of Polypropylene Fibers in Concrete," SCI Seminar 2004.
Aulia, T. B., "Effects of Polypropylene Fibers on the Properties of High-Strength Concretes." LACER No. 7 (2002), pp.43-59.
Waheeb, A. L. K., "Mechanical Properties and Time Dependent Defor- mations of Polypropylene Fibre Reinfor- ced Concrete," J King
Saud Univ., Vol. 7, Eng.Sci. (1) (1993),pp. 67-76.
Choi, Y., Yuan, R.L., "Experimental Relationship between Splitting Tensile Strength and Compressive Strength of GFRC and PFRC",
Cement and Concrete Research, Vol. 35 (2005) pp.1587-1591.
Antoni, Honguchi T. and Saeki N."Inퟢ�uence of Stress on Chloride Penetration into Fiber Reinforced Concrete ", JCI,Vol.25 (2003),
pp.779-784.
Malisch,W. R., "Polypropylene 韛�bers in concrete."
Sukontasukkul, P., "Toughness Valuation of Steel and Polypropylene Fibre Reinforced Concrete Beams under Bending" Thammasat
Int. J. Sc. Tech., Vol. 9, No. 3, (2004),pp.35-41.
Ritchie, A.G.B. and Mackintosh, D.M., "Selection and Rheological Characteristics of PP 韛�bers," Concrete, pp 36-39 (1972).
Hughes, B.P. and Fattuhi, N.I., "Fibrer Reinforced Concrete in Direct Tension," Fiber Reinforced Materials, paper 16, conference at
Institution of Civil Engineers, London. 1977, pp 127-133.
Hadi, M. N. S., "An Investigation of the Behaviour of Steel and Polypropylene Fibre Reinforced Concrete Slabs," 7th International
Conference. Concrete: Construction’s Sustainable Option - Harnessing Fibres for Concrete Construction, Dundee, Scotland, 8-10 July
2008.
Suhaendi, S. L., "Residual Strength and Permeability of Hybrid Fiber Reinforced High Strength Concrete Exposed to High
Temperature" Part of Ph. D. Thesis.

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Alidoust, O., Sadrinejad, I. and Ahmadi, M. A., "A Study on Cement-Based Composite Containing Polypropylene Fibers and Finely
Ground Glass Exposed to Elevated Temperatures." Procedings of World Academy of Science, Engineering and Technology Vol. 23.
CREATE AN ACCOUNT (/component/compro韛�ler/registers.html)
Suji, D., Natesan, S. C., Murugesan, R., "Experimental study on behaviors of polypropylene 韛�brous concrete beams" Journal of
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A pp 1862-1775.
Carnio, M. A., Gomes, A. E. and Lintz, R. C. C., "Fiber reinforced Concrete" Technical Report on Average Residual Strength (ARS),
ASTM C 1399-7a.
Wang Y., Victor C. Li., Backer S., "Tensile Properties of Synthetic Fiber Reinforced Mortar," Cement and Concrete Composites Vol.12
(1990) pp 29-40.
Singh S.K.et.al. "Internal Report on Steel Free Deck Slab",SERC, Ghaziabad (2000)
Shiv Kumar, A. & Sathanam,M. "Machanical Properties of High Strength Concrete Reinforced with Metallic and Non Metallic
Fibres",Cement & Concrete Composites, Vol.27(2007),pp.603-608.
Xing, L.B.;Xiang C.M.; Farg C. & Luping L. "The Mechanical Properties of Polyproplene Fiber Reinforced Concrete", Journal of Wahan
University of Technology, Material Science ED.,Vol.19, No.3 (2004), pp.68-71.

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