This document summarizes an experimental study on polypropylene fiber reinforced moderate deep beams. Six beams of varying depths from 150mm to 300mm were cast with polypropylene fiber contents ranging from 0% to 1% by volume. The beams were tested under two-point loads to evaluate properties such as compressive strength, flexural strength, shear stress, ductility, and failure patterns. The results showed that the addition of polypropylene fibers significantly improved the mechanical properties of the beams and increased their resistance to brittle failure. Beams with higher fiber contents exhibited higher load capacities, greater deformability, and more ductile failure modes compared to beams without fibers.

1. International Journal of Civil Engineering and Technology (IJCIET), ISSN 0976 – 6308
INTERNATIONAL JOURNAL OF CIVIL ENGINEERING AND
(Print), ISSN 0976 – 6316(Online) Volume 4, Issue 1, January- February (2013), © IAEME
TECHNOLOGY (IJCIET)
ISSN 0976 – 6308 (Print)
ISSN 0976 – 6316(Online)
Volume 4, Issue 1, January- February (2013), pp. 126-131 IJCIET
© IAEME: www.iaeme.com/ijciet.asp
Journal Impact Factor (2012): 3.1861 (Calculated by GISI)
www.jifactor.com © IAEME
“EXPERIMENTAL STUDY ON POLYPROPYLENE FIBER
REINFORCED MODERATE DEEP BEAM”
V.R.Rathi [1] A.B.Kawade [2] R.S.Rajguru[3]
1 Associate Professor,Pravara rural engineering college, Loni, (MS), India.
2 Asst. Professor, Amrutvahini College of engineering, Sangamner, (MS), India.
3 P.G.Student, Pravara rural engineering college, Loni, (MS), India.
ABSTRACT
In present study, the result of polypropylene fiber reinforced moderate deep beam
with and without stirrups have been presented. Six beams of constant overall span and depth
150mm, 200mm, 250mm, 300mm with span to depth (L/D) ratios of 4 ,3, 2.4, & 2 and
Polypropylene fibers of 12mm cut length and 6 denier were added at volume fraction of 0%,
0.25%, 0.50%, 0.75% & 1 %.The beams were tested under two point loads at mid span. The
results showed that the addition of polypropylene fiber significantly improved the
compressive strength, split tensile strength, flexural strength, shear stress, reserve strength
and ductility of reinforced moderate deep beam without stirrups.
Keyword: polypropylene fiber, compressive strength, split tensile strength, flexural strength,
shear stress
1.0 INTRODUCTION
An attempt has been made through this work to understand the shear stress & flexural
strength response of moderate deep beams under fibrous matrix as they predominantly fail
under shear and their strength is likely to be controlled by shear rather than flexure provided
with nominal amount of longitudinal reinforcement. A very little works have been reported
on shear strength and flexural deformational behavior of fibrous Reinforced Cement Concrete
moderate deep beams Moderate deep are shear predominant members and generally fail in
brittle shear mode.
126

2. International Journal of Civil Engineering and Technology (IJCIET), ISSN 0976 – 6308
(Print), ISSN 0976 – 6316(Online) Volume 4, Issue 1, January- February (2013), © IAEME
Concrete has disadvantage that it fails in brittle manner. The fibers can make failure
mode more ductile by increasing the tensile strength of concrete. As a result a structural
performance can be improved. The addition of polypropylene fibers to a reinforced concrete
beam is known to increase its shear strength and if sufficient fibers are added, a ductile shear
failure can be suppressed in favor of more ductile behavior. The use of polypropylene fibers
is particularly attractive if conventional stirrups can be eliminated, which reduces
reinforcement congestion.
Many researchers like Vinu R. Patel, Ankur Rana and I. I. Pandya have confirmed
addition of polypropylene fiber show enhanced shear strength and energy distribution
capacity. There are only few studies reporting results on the behavior of beams reinforced
with a new type of polypropylene Fibrillated mesh fibers. This fiber has a higher modulus of
elasticity and an optimized geometry to enhance the bond between the fiber and the concrete
matrix, which leads to an increase in the toughness properties of concrete. If sufficient fibers
are added, a brittle failure can be suppressed in favor of more ductile behavior. The increased
strength and ductility of fiber-reinforced beams.
2.0 EXPERIMENTAL PROGRAMME
2.1 Test Materials:
Ordinary Portland Cement (OPC) of 43 grade, natural river sand of fineness modulus
4.175 and 20mm coarse aggregate were used. The concrete mix was in proportion of 1:
1.272: 2.766 by weight and water cement ratio of 0.43 kept constant for all beam.
Polypropylene fibers of 12mm cut length and 6 denier wear used. The workability of
polypropylene fiber reinforced concrete mixtures was maintained by adjusting the dosage of
super plasticizer to offset the possible reduction in slump. For each series of beams, three
cubes (150X150X150) mm and three cylinders (150mm diameter, 300mm high) as control
specimen were cast. Cubes were tested for crushing strength at 28 days and cylinder were
tested for splitting tensile strength at 28 days.
2.2 Specimen Details
Tests were carried out on six beams, simply supported on constant effective span of
600mm and width of 150mm under two point concentrated symmetrical loading.
There were four series of beams having different depths of 150mm, 200mm, 250mm, 300mm
and Polypropylene fibers wear added at volume fraction of 0%, 0.25%, 0.50%, 0.75% & 1
%.All beams provided with anchor bars of 2-8 mm, bottom steel of 2-10mm of grade Fe500
and only beam of 0% fiber volume fraction were provided with 6mm stirrups of grade
Fe250.The beam notation “D150” denotes the beam having overall depth 150mm.
2.3 Testing Procedure
The beams were tested under two point concentrated loading at their mid span in a
universal testing machine. A dial gauge was fixed at bottom of beam to measure mid span
deflection at interval of 0.5mm and corresponding load were noted. The loading at which first
crack and ultimate crack appeared was noted. The pattern and propagation of cracks was
noted, up to failure of beam.
127

3. International Journal of Civil Engineering and Technology (IJCIET), ISSN 0976 – 6308
(Print), ISSN 0976 – 6316(Online) Volume 4, Issue 1, January February (2013), © IAEME
January-
Table 1 Compressive strength and split tensile strength Test Results
Cement Water Fiber Average Average split tensile
sand:coarse: cement volume compressive strength
aggregate ratio fraction strength (N/mm2)
(%) (N/mm2)
1:1.272: 2.766 0.43 0 33.55 2.78
1:1.272: 2.766 0.43 0.25 34.44 2.97
1:1.272: 2.766 0.43 0.50 34.81 3.06
1:1.272: 2.766 0.43 0.75 35.18 3.19
1:1.272: 2.766 0.43 1 36.00 3.30
Table 2 Average flexural strength and Average shear stress
Span-depth % Fiber volume Average flexural Average shear
Sr. No.
ratio(L/D) fraction(Vf) strength (N/mm2) stress (N/mm2)
1 4 0 15.13 2.83
2 4 0.25 15.87 2.97
3 4 0.50 17.23 3.21
4 4 0.75 17.56 3.33
5 4 1 17.85 3.35
6 3 0 9.49 2.37
7 3 0.25 10.18 2.55
8 3 0.50 10.60 2.65
9 3 0.75 11.25 2.81
10 3 1 10.46 3.01
11 2.4 0 6.88 2.15
12 2.4 0.25 7.19 2.25
13 2.4 0.50 7.53 2.36
14 2.4 0.75 8.02 2.51
15 2.4 1 7.75 2.65
16 2 0 5.18 2.17
17 2 0.25 5.46 2.38
18 2 0.50 6.05 2.56
19 2 0.75 6.39 2.80
20 2 1 5.48 2.84
3.0 RESULT AND DISCUSSION
20
Flexural Strength
L/D=4
10
(MPa)
L/D=3
0
L/D=2.4
L/D=2
% Fiber Volume Fraction (Vf)
Fig.1 Flexural strength Vs % Fiber Volume Fraction
128

4. International Journal of Civil Engineering and Technology (IJCIET), ISSN 0976 – 6308
(Print), ISSN 0976 – 6316(Online) Volume 4, Issue 1, January- February (2013), © IAEME
January
3
Shear Stress (Mpa)
2 L/D=4
1 L/D=3
0
L/D=2.4
0 0.5 1
L/D=2
% Fiber Volume Fraction
Fig.2 Shear Stress Vs % Fiber Volume Fraction
120 140
100 120
Load (kN)
0 % Fiber
Load (kN)
0 % Fiber 100
80 80
60 60
40 40
20 0.25 % 20 0.25 %
0 Fiber 0 Fiber
0123456789 0.50 % 0123456789 0.50 %
Deflection (mm) Fiber Deflection (mm) Fiber
Fig.3 Load Vs Deflection
(L/D=4 and 3)
140 200 0 % Fiber
120 180
160
Load (kN)
Load (kN)
100 0% 140
80 Fiber 120
60 100 0.25 %
80
40 0.25 % 60 Fiber
20 40
Fiber 20
0 0 0.50 %
012345678 0.50 % 0123456789
10 Fiber
Fiber 0.75 %
Deflection (mm) Deflection (mm)
Fiber
Fig.4 Load Vs Deflection
(L/D=2.4 and 2)
3.1 Discussion of Crack Patterns and Mode of Failure
f
The complete failure of the beam was observed to occur in one of the following ways: (i) The
ways
beams were collapsed by flexure with a flexural crack near to mid-span. This type of failure was
mid span.
observed in beams of L/D =4, L/D =3 series. (ii) The diagonal tension failure, observed in the
nal
majority of the beams of L/D =2.4, L/D =2 series, was indicated by splitting of beam in the direction
of a line joining the inner edge of the support to the outer edge of the loading plate. Beam of series
L/D =2.4 mainly failed in flexure- -shear mode. While beams of series L/D =2 failed in pure shear
mode.
The shear compression failure was indicated by crushing of the strut like portion of the
concrete between two adjacent parallel diagonal cracks accompanied by splitting of the concrete along
the plane of the diagonal cracks and was followed by crushing and bursting in the web. This type of
failure observed in some of beams of series L/D=2.
129

5. International Journal of Civil Engineering and Technology (IJCIET), ISSN 0976 – 6308
(Print), ISSN 0976 – 6316(Online) Volume 4, Issue 1, January- February (2013), © IAEME
Table 3 Reserve Strength and ductility
Reserve Strength Ductility
Span- First Ultimate (Wu-Wc/Wc) Deflection at Deflection at m=
% Fiber
Depth Crack Crack X100, % First Crack Ultimate (Du/Dc)
Volume
Ratio Load Load Load Crack Load
Fraction(Vf)
(L/D) Wc, (kN) Wu, (kN) Dc, (kN) Du, (kN)
0 50.240 85.120 69.42 2.20 4.20 1.90
0.25 51.973 89.300 71.81 2.00 4.50 2.25
4 0.50 55.940 96.290 72.13 2.15 4.63 2.15
0.75 57.682 99.850 72.48 1.92 4.60 2.39
1 58.180 100.447 72.64 1.76 4.50 2.55
0 56.880 94.970 66.96 2.42 4.50 1.85
0.25 58.262 101.860 74.83 2.40 4.50 1.87
0.50 60.198 106.100 76.25 2.36 4.52 1.91
3
0.75 63.780 112.560 76.37 2.41 4.50 2.28
1 69.780 120.669 72.92 2.24 5.53 2.46
0 70.383 107.613 52.89 2.78 5.20 1.87
0.25 73.149 112.436 53.70 2.54 5.00 1.96
2.4 0.50 75.060 117.842 56.99 2.64 5.43 2.05
0.75 80.980 125.447 54.91 2.48 5.54 2.23
1 87.745 132.715 51.25 2.53 6.20 2.45
0 82.672 129.713 56.90 3.78 6.00 1.58
0.25 85.120 144.563 69.83 3.25 6.00 1.77
2 0.50 96.553 154.960 67.42 3.36 6.50 1.93
0.75 110.713 169.342 52.95 3.34 6.42 1.79
1 117.968 172.507 46.23 3.30 6.00 1.81
4.0 CONCLUSIONS
Following conclusion are drawn from the experimental results,
1) The increase in average compressive strength for PPFC is found 7.30 %. Compared to
PCC. The maximum compressive strength is achieved with 1% fiber volume fraction.
2) The increase in split tensile strength is found 18.70 %. The maximum split tensile
strength achieved with polypropylene fibers having volume fraction 1 %.
3) The increase in reserve strength for L/D=4, 3, 2.4 and 2 of moderate deep beam is
found 4.63%, 14.05%, 7.75% and 22.72% respectively by inclusion of 1%, 0.75%,
0.50% and 0.25% polypropylene fiber respectively.
4) The increase in ductility for L/D=4,3 and 2.4 of moderate deep beam is found 32.76
%, 32.97% and 31.01% respectively by inclusion of 1% polypropylene fiber and The
increase in ductility for L/D= 2 is found 19.48 % by inclusion of 0.50%
polypropylene fiber.
5) The flexural strength for L/D=4 of moderate deep beam increases is 17.97% by
inclusion of 1% polypropylene fiber and for L/D=3, 2.4 and 2 average increment is
about 19.48 % by inclusion of 0.75% polypropylene fiber.
6) The shear stress of moderate deep beam increases by 24.97% by inclusion of 1%
polypropylene fiber which helps to reduce stirrup requirement.
130

6. International Journal of Civil Engineering and Technology (IJCIET), ISSN 0976 – 6308
(Print), ISSN 0976 – 6316(Online) Volume 4, Issue 1, January- February (2013), © IAEME
REFERENCES
1) G. Appa Rao et al., “Studies on effect of size on strength and ductility of RC deep
beams.” Journal of Structural Engineering, Vol.36, No. 6, Feb.-March,2010, pp. 393-400.
2) Lesley H.Sneed et al., “Influence of Effective Depth on Shear Strength of Concrete
Beam-Experimental Study” ACI Structural Journal, v. 107, No. 5, Sep.-Oct. 2010, pp.
554-562.
3) Mohamed Zakaria et al., “Experimental Investigation on Shear Cracking Behaviour in
Reinforced Concrete Beam with Shear Reinforcement.”Journal of Advanced Concrete
Technology Vol.7, No.1, pp79-96.
4) Rana A. Mtasher et al., “Strength Prediction of Polypropylene Fiber Reinforced
Concrete” Eng. &Tech Journal Vol.29, No.2,2011.
5) Saeid Kakooei et al., “The effects of polypropylene fibers on the properties of reinforced
concrete structures” Construction and Building Materials 27 (2012) 73–77.
6) Salah Altoubat, Ardavan Yazdanbakhsh, and Klaus-Alexander Rieder,” Shear Behavior
of Macro-Synthetic Fiber-Reinforced Concrete Beams without Stirrups” ACI Mat. Jl.,
Vol 106, No.4, July-August 2009, Title No. 106-M44.
7) Vinu R. Patel, Ankur Rana And I.I. Pandya, “Shear strength of polypropylene fiber
reinforced concrete moderate deep beams without stirrups”, Title No.37-T11, Journal of
structural engineering Vol. 37 No.5 December 2010-January-2011, pp. 364-368
8) Vinu R. Patel And I.I. Pandya, “Micro Mechanical Measurement of Concrete Strain to
Evaluate Principle Strain Distribution in Steel Fiber Reinforced Cement Concrete
Moderate Deep Beams across it’s width and depths”, International Journal of civil and
structural engineering Vol.1 No.2 2010, ISSN 0976-4259.
9) Vinu R. Patel and I.I. Pandya, “Evaluation of shear strain distribution in polypropylene
fiber reinforced cement concrete moderate deep beams”, International Journal of civil and
structural engineering Vol.1 No.3 2010, ISSN 0976-4399.
10) IS 456:2000, “Plain and Reinforced Concrete Code of Practice”, Fourth revision, Bureau
of Indian Standards (BIS 2000).
11) IS-10262-1982, Recommended Guidelines for Concrete Mix Design, Bureau of Indian
Standards.
12) Shetty.M.S. “Concrete Technology, Theory and Practice”, S. Chand & Company,
New Delhi.
13) Adil M. Abdullatif and Tareq S. Al-Attar, “Structural Behavior Of Reed: Evaluation Of
Tensile Strength, Elasticity and Stress-Strain Relationships”, International Journal Of
Advanced Research In Engineering & Technology (IJARET), Volume 4, Issue 1, 2013,
pp. 105 - 113, Published by IAEME.
14) Ansari Fatima-uz-Zehra and S.B. Shinde, “Flexural Analysis Of Thick Beams Using
Single Variable Shear Deformation Theory”, International Journal of Civil Engineering &
Technology (IJCIET), Volume 3, Issue 2, 2012, pp. 292 - 304, Published by IAEME.
15) Misam.A and Mangulkar Madhuri.N, “Structural Response Of Soft Story-High Rise
Buildings Under Different Shear Wall Location”, International Journal of Civil
Engineering & Technology (IJCIET), Volume 3, Issue 2, 2012, pp. 169 - 180, Published
by IAEME.
131