a study on combination of steel and glass fibers...

© January 2017 | IJIRT | Volume 3 Issue 8 | ISSN: 2349-6002

IJIRT 144189 INTERNATIONAL JOURNAL OF INNOVATIVE RESEARCH IN TECHNOLOGY 35

A STUDY ON COMBINATION OF STEEL AND

GLASS FIBERS AS HYBRID FIBERS IN CONCRETE

N.N.Pavan Kumar1, T.Raja Shekar2, and P.Tejeswar Kumar3 1M.Tech Student, Jogaiah Institute of Technology and Science, Kalagampudi

2Head of the Department, Jogaiah Institute of Technology and Science, Kalagampudi 3Assistant Professor, Jogaiah Institute of Technology and Science, Kalagampudi

Abstract—Concrete is a brittle material when subjected

to normal stresses and impact loads, where tensile

strength is relatively low compared to compressive

strength. This can be improved by addition of fibrous

material. The geometric size and modulus of fibers are

the main factors influence the mechanical performance

of fiber reinforced concrete. The use of different type of

fibers in a suitable combination may potentially improve

the overall mechanical performance of concrete and

increase tensile strength, energy absorption capacity of

concrete. The present investigation studies the synergic

mechanical properties of hybrid fiber polymer

reinforced concrete. The properties of plain concrete,

mono steel fiber concrete, glass fiber concrete and hybrid

fiber concrete of M20 grade were studied and the

properties of hybrid fiber concrete are compared with

respect to plain and mono steel fiber and glass fiber

concrete. Similarly the axial stress-strain curves under

Axial Compression are studied.

Index Terms—Fiber, synergic mechanical properties,

hybrid fiber polymer, mono steel fiber and glass fiber

concrete

I. INTRODUCTION

Concrete is acknowledged to be a relatively brittle

material when subjected to normal stresses and impact

loads, where tensile strength is approximately just one

tenth of its compressive strength. As a result for these

characteristics, concrete flexural members cannot

support such loads that usually take place during their

service life. Historically, concrete came to be

reinforced with continuous reinforcing bars to

withstand tensile stresses and to compensate for the

lack of ductility and strength.

More energy is required for propagation of cracks into

the hardened cement paste than around the coarse

aggregate. Due to the sharpness of the cracks in the

concrete the rate of propagation of the cracks is higher

than ductile material. That is why the concrete

possesses lower strain level at failure. The propagation

of the crack in the concrete is perpendicular point to

the principal tensile stress acting at that point .This is

the case both in compression and tension. In the direct

tension, cracks open up in a plane perpendicular to the

direction the load applied. In the compression, the

cracks open up due to lateral strain which induces the

tensile stress. With increasing compressive stress, the

lateral strain increases and the energy gets dissipated

by the propagation of cracks creating new surfaces.

Then the failure takes place by splitting of the

concrete.

II. MATERIALS

A. Cement

The Cement used in the investigation was 53 Grade

Ordinary Portland cement confirming to IS:

12269[1987]. The cement was obtained from a single

consignment and was of the same grade and same

source. The specific gravity, standard consistency and

initial setting time are respectively 3.11, 33% and

35min.

B. Fine aggregate

The fine aggregate conforming to Zone-2 according to

IS: 383[1970] were used. The fine aggregate used was

obtained from a nearby river source. The bulk density,

specific gravity and fineness modulus of the sand used

were 1.41g/cc, 2.60 and 2.90.The sand obtained was

sieved as per IS sieves (i.e.2.36, 1.18,600,300 and

150mm). Sand retained on each sieve was filled in

different bags and stacked separately for use. To

obtain zone-2 sand correctly, sand retained on each

sieve was mixed in appropriate proportion in which

each size fraction



C. Coarse aggregate

Crushed granite Aggregate was used as coarse

aggregate. The coarse aggregate used was obtained

from a local crushing unit having 20mm normal size,

well graded aggregate according to IS: 383[1970]. The

bulk density, specific gravity and fineness modulus of

the coarse aggregate used were 1.46g/cc, 2.78 and 7.1

respectively. The coarse aggregate procured from

quarry was filled in bags and stacked separately.

D. Water

Potable water was used in the experimental work for

both mixing and curing.

E. Steel fibers

Initially, round steel fibers were produced by cutting

smooth high tensile steel wire of uniform cross

section; much of it rejected portions of the wire used

in steel belted radial lines. To improve the quite low

resistances to fiber pull out of smooth uniform fibers.

The object was to augment the adhesive bond by

introducing mechanical interlock between fiber and

matrix in the same way that deformed rebar improves

bond compared with smooth rebar. Keeping in view of

this above, fiber diameter is chosen to give raise the

desired aspect ratio. An Aspect ratio of 60 (0.5 mm

diameter and 30 mm length) is adopted. The properties

of steel fibers are shown in the table1

Table1. Physical and mechanical properties of steel

fibers

III. METHODOLOGY

In this study M20 Standard Grade of Concrete is being

used. Mix design is carried out as per IS: 10262(2009)

code stipulations and proportions corresponding to

M20 are arrived at as 1:1.5:3:0.6

IV. EXPERIMENTS ON HYBRID FIBER

REINFORCED CONCRETE

A. Fresh properties of hybrid fiber reinforced concrete

The fresh properties of hybrid fiber reinforced

concrete include measuring the workability of

concrete by slump cone test. For various proportions

of fiber content the slump values are noted. Slump test

is the most commonly used method of measuring

consistency of concrete which can be employed either

in the laboratory or at site work. The apparatus for

conducting the slump test essentially consists of a

metallic mould in the form of a frustum of a cone

having the internal dimensions as bottom diameter of

20cm, top diameter of 10cm and an height of

30cm.The slump cone is shown in fig1

Fig 1. Slump cone test

B. Hardened properties of hybrid fiber reinforced

concrete

1) Compressive strength

The cube specimens were tested in a standard

compression testing machine .The bearing surface of

the machine was wiped off clean and any loose sand

or other material removed from the surface of the

specimen . The axes of the specimens were carefully

aligned at the center of the loading frame. The load

applied was increased continuously at a constant rate

until the resistance of the specimen to the increasing

load breaks down and no longer can be sustained. The

maximum load applied on the specimen was recorded.

The rate of loading was adopted as per IS 516 [1956]

Fig 2.Cubes testing in universal testing machine for

compressive strength

2) Split tensile strength

The bearing surface of the casting was wiped clean, in

case of cylindrical specimens the test was carried out

Property Steel fibers

Length(l) 30mm

Diameter(d) 0.5mm

Aspect ratio(l/d) 60

Specific gravity 7.8

Tensile strength 1700 MPa

Elastic modulus 200 GPa

Failure strain 3.5%



by placing the specimen horizontally between the

loading surfaces of the compression testing machine

for split tensile strength and the axis of the specimen

was carefully aligned with center of the loading

frames. The load was applied and increased

continuously till the specimen breaks. The maximum

load was recorded. The test was performed as per IS

516 [1956]. By obtaining the failure load the split

tensile strength is calculated using the formulae

Split tensile strength = 2P/ (3.14DL)

Where, P = Failure load, D = Diameter of cylinder

And L = Length of cylinder

Fig 2.Cylinders testing in UTM to find split tensile

strength

3) Flexural tensile strength

The flexural strength of the specimen is expressed as

the modulus of the rupture. The method used in testing

is third point loading.. The strength in the bearing is

the extreme fiber stress on the tensile side at the point

of the failure. The test was performed as per IS 516

[1956]. If ‘a’ equals the distance between the line of

fracture and the nearer support, measured on the

centered line of the tensile side of the specimen, in cm,

is calculated to the nearest 0.05 MPa as follows

when ‘a’ is greater than 20.0

cm for 15 cm specimen or greater than 13.3 cm for a

10.0 cm specimen, or

When ‘a’ is less than

20.0 cm but greater than 17 cm for 15 cm specimen, or

less than 13.3 cm but greater than 11 cm for a 10 cm

specimen where

b = measured width in cm of the specimen,

d = measured depth cm of the specimen at the point of

the failure,

l = length in cm of the span on which the specimen

was supported, and

P =Max. Load in kg applied to the specimen.

If ‘a’ is less than 17 cm for a 15 cm specimen, or less

than 11 cm for a 10 cm specimen, the results of the test

be discarded.

Fig 3.Prisms testing for flexural strength

4) Testing for Stress-Strain Curve

The cured specimens are capped with plaster of Paris

before testing to provide a smooth loading surface.

The set up of two square frames along with the

compressometer is used for measuring the strains.

Tests are continued until the peak load dropped to

about 0.5 times the peak load. Beyond the peak load,

the strains increased at a rapid rate and are

accomplished with a decrease in the load carrying

capacity of the specimen.

Fig 4.Cylinders testing for stress-strain curve

Fig 5.Prisms testing in tensile testing machine for load-

deflection curves



V. RESULTS AND DISCUSSIONS

A. Compressive strength

Table 2.Compressive loading test results of plain

concrete

S.NO Load(KN) Compressive

strength (MPa)

1 610 27.11

2 625 27.77

3 645 28.66

Average 27.84

B. Split tensile strength

Table 3.Split tensile strength test results for plain

concrete

S.No Load(KN) Split tensile

strength

(MPa)

1 200 2.82

2 180 2.54

3 220 3.11

Average 2.82

C) Flexural strength

Table 4.Flexural strength test results for plain concrete

S.No Load(KN) Flexural

strength

(MPa)

1 6.76 3.38

2 6.81 3.40

3 7.10 3.55

Average 3.44

D) Hybrid fiber reinforced concrete

The hybrid fiber concrete is prepared with optimum

dosage of steel fiber concrete (1.0% by volume of

concrete) and varying the proportion of glass fibers

keeping SBR latex content constant as 2% by weight

of cement. Initially trial mixes were conducted with

various proportions and based on that the proportions

of glass fibers are 0.1%, 0.2%, 0.3%, 0.4% and 0.5%

by volume of concrete respectively. The various Mix

ID are AP- Plain AS- Steel fiber, AG- Glass fiber and

ASG- Steel and glass fiber

Table 5.Dosage of different fiber combinations used in

the study

Mix ID

Volume

fraction of steel

fibers

Volume

fraction of

glass fibers

(%) (%)

AS 1 0

AG 0 0.5

ASG 1 0.5

Bar chart 1: Comparison of compressive strength of

plain, mono steel fiber, glass fiber and hybrid fiber

concrete

Bar chart 2: Split tensile comparison between plain,

mono steel fiber, glass fiber and hybrid fiber

Bar chart 3: comparing flexural strength of plain, mono

steel fiber, Glass fiber and hybrid fiber concrete

27.84

30.529.4

33.03

24

26

28

30

32

34

AP AS AG ASG

Co

pre

ssiv

e S

tre

ngt

h in

M

Pa

compressive strength in MPa

0

1

2

3

4

5

AP AS AG ASG

Split

Te

nsi

le S

tre

ngt

h

inM

Pa

Split Tensile strength in MPa

0

1

2

3

4

5

6

AP AS AG ASG

Fle

xura

l Str

en

gth

in M

Pa

Flexural Strength in MPa



Graph1: Axial Stress -Strain for plain concrete

Graph 2: Axial Stress -Strain curve for Mono Steel

fiber Concrete

Graph 3: Axial Stress -Strain curve for Glass fiber

concrete

Graph 4: Axial Stress-Strain Curves comparing all

types of fiber concretes

VI. CONCLUSION

The following are the conclusions from the present

study

1. It is possible to produce hybrid fiber polymer

concrete composites using glass fibers in

combination with steel fibers with an

enhancement in the mechanical properties of

concrete, toughness and ductility of the concrete

2. The increase in the compressive strength, split

tensile strength and flexural strength of hybrid

fiber polymer concrete compared to plain

concrete are 25%, 45% and 41% respectively.

Similarly the percentage increase of

compressive, split tensile and flexural strength of

hybrid fiber compared to mono steel fiber are

1.4%, 25% and 15% respectively.

3. Increased fiber availability of glass fibers in

bridging smaller micro cracks could be the

reason for the enhancement in split and flexural

properties.

4. The post peak behavior mainly depends on the

steel fibers as the glass fibers are inability to

sustain high crack widths resulting at large

deflections.

5. There is enhancement in energy absorption

capacity due to addition of fibers and polymer

which indicates the increase in ductility of

concrete.

6. A major significance of these findings is that

steel fibers in concrete could be replaced to a

0

5

10

15

20

25

0 0.002 0.004

STR

ESS

in M

Pa

STRAIN

AP

0

10

20

30

0 0.002 0.004 0.006

Stre

ss in

MP

a

Strain

AS

0

5

10

15

20

25

0 0.002 0.004 0.006

Stre

ss in

MP

a

Strain

AG

-505

1015202530354045

0.0000 0.0020 0.0040 0.0060 0.0080

STR

ESS

in M

Pa

STRAIN

ASG AP-0% AS-1% AG-0.5%

Hybrid Fibers



small extent with glass to provide better

properties of the concrete.

7. Jogaiah Institute of Technology and Science,

Kalagampudi.

FUTURE SCOPE

1. The study can expand to Study of behavior of

hybrid fibers in self compacting concrete, high

strength, self compacting/curing and other

modern type of concretes to observe the influence

and improvement in the behavior of concrete in

terms of its energy absorption and fracture.

2. There is need to Study of hybrid fibers with latex

as polymer under torsion and shear.

3. The study of behavior of hybrid fiber polymer

concrete for high strength concretes

4. The study of different type of hybrid fiber

combinations like steel- glass fiber, steel-

polypropylene fiber with different types of

polymers.

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enhancement in steel fiber reinforced concrete

through fiber hybridization’, Cement and

Concrete Research 37 (2007) 1366–1372

[2] Y. Ohama, S. Kan andM.Miyara, ‘Flexural

behavior of steel fiber reinforced polymer

modified concrete’, Trans. Japan Concr. Inst. 4,

1982, 147–152

[3] C.X. Qian, P. Stroeven, ‘Development of

hybrid polypropylene-steel fiber-reinforced

concrete’, Cement and Concrete Research 30

(2000) 63–69

[4] Chunxiang Qian, Piet Stroeven, Fracture

properties of concrete reinforced with steel and

polypropylene hybrid fibers

[5] M. Glavind, T. Aarre, High-strength concrete

with increased fracture toughness, in: Sidney

Mindess, Jan Skalny (Eds.), Fiber-reinforced

Cementitious Materials: Symposium, Boston,

Massachusetts, 1990, Materials Research

Society Symposia Proceedings, vol. 211,

Materials Research Society, Pittsburgh, 1991,

pp. 39–46.

[6] Symposia Proceedings, vol. 305, Materials

Research Society, Pittsburgh, 1993, pp. 123–

128

[7] Machine Hsie, Chijen Tu, P.S. Song,

‘Mechanical properties of polypropylene

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Science and Engineering A 494 (2008) 153–

157

[8] A. Sivakumar, Manu Santhanam, ‘Mechanical

properties of high strength concrete reinforced

with metallic and non-metallic fibers’ Cement

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[9] A. Sivakumar, Manu Santhanam,’ A

quantitative study on the plastic shrinkage

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(2007) 575–581

[10] G. Barluenga, F. Hernandez-Olivares,’SBR

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behavior’, Cement and Concrete Research 34

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[11] Fang Xu, Mingkai Zhou, ‘Mechanical

performance evaluation of polyester fiber and

SBR latex compound-modified cement

concrete road overlay material’, Construction

and Building Materials 63 (2014) 142–149

[12] Gengying Li, Xiaohua Zhao, Chuiqiang Rong,

Zhan Wang, ‘Properties of polymer modified

steel fiber-reinforced cement concretes’,

Construction and Building Materials 24 (2010)

1201–1206

[13] IS:456-2000‘plain and reinforced concrete code

of practice’

a study on combination of steel and glass fibers...

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