behavior of cfst infilled with frc under monotonic · pdf filea concrete filled steel tube...

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Research Article May 2016 Special Issue on International Conference on Advances in Engineering (ICAE) -2016 Conference Held at Hotel Magaji Orchid, Sheshadripuram, Bengaluru, India. © 2016, IJERMT All Rights Reserved Page | 66 International Journal of Emerging Research in Management &Technology ISSN: 2278-9359 (Volume-5, Issue-5) Behavior of CFST Infilled with FRC under Monotonic Loading 1 Khalid Nayaz Khan, 2 Sudha K 1 Associate Professor, civil Engineering Department , Ghousia College of Engineering, Ramanagaram, Karnataka, India 2 Master of Technology (Structural Engineering) Student, Civil Department, Ghousia College of Engineering, Karnataka, India AbstractIn this paper, experimental investigation on the behaviour of concrete filled steel tube infilled with Polypropylenefibre (PPF) under monotonic loading is carried out. Here the strength of 54 Specimens was tested. The parameters varied in this study are 1) percentage of PPF (0%, 0.2%, 0.3%, 0.4%) 2) Diameter of the hollow circular steel tubes (33.7mm and 42.4mm) 3)L/D ratios(10,12 and 14) and 4) Grades of concrete(M20 and M30). The thickness of steel tubes is 3.2mm which remains same for all the specimens. Polypropylene fiber concrete filled steel columns exhibit higher strength than steel tubes filled with conventional concrete. The results show that load carrying capacity increased with increase in percentage of polypropylene fiber and also the energy absorption capacity was enhanced. From the hollow steel tube results it was observed that the load carrying capacity of the steel tube decreased as the D/t ratio increased. KeywordsConcrete filled steel tube (CFST), Polypropylene fiber(PPF) I. INTRODUCTION A Concrete filled steel tube (CFST) column is a structural system with excellent structural characteristics, which is the result of combining the advantages of a steel tube and those of concrete. A CFST column is constructed by filling a hollow rectangular or circular structural steel tube with concrete. As a structural system, a CFST column has a, excellent earthquake-resistance, high load bearing capacity good ductility, high fire resistance and its higher stiffness which delays the local buckling. In recent years, intensive research has resulted in advances and innovative technology of fiber such as glass, polypropylene, carbon etc., and more basic knowledge has been gained on behavior of cement concrete containing these fibers. The incorporation of short discrete polypropylene fiber can lead to useful improvements in the mechanical behavior of tension of weak concrete. II. ADVANTAGE OF USING CFST OVER ENCASED COLUMNS Composite column combines the advantages of both structural steel & concrete, namely the speed of construction, strength, & light weight steel, & the inherent mass, stiffness, damping, & economy of concrete. The steel frame serves as the erection frame to complete the construction of the rest of the structure. Thus improving ductility. Concludes that the concrete infill delays the local buckling of the steel tube. However, no increase in concrete strength due to confinement by steel tube was observed. Types of cfst columns Based on the cross-sections of the steel tubes, CFST tubes are classified as circular, rectangular and square shapes and these tubes are most commonly used ones Square Concrete encased steel (CES) Fig 1. Types of CFST colum a) Square Concrete encased steel (CES) b) circular and square CFST c) Combined both CFST and CES d) Hollow circular and square CFST sections e) Double skinned circular and square CFST sections III. MATERIALS AND METHODOLOGY CONCRETE Design mixes are prepared using locally available Portland Pozzolana Cement (PPC), crushed granite jelly (12.0mm down) and river sand. Mix designs of these two grades (M20, M25) of concrete are made based on the guidelines of IS 10262-1982. The mix proportions adopted for the two grades of concrete are shown in table below.

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Page 1: Behavior of CFST Infilled with FRC under Monotonic · PDF fileA Concrete filled steel tube (CFST) column is a structural system with excellent structural characteristics, ... abaqus

Research Article

May 2016

Special Issue on International Conference on Advances in Engineering (ICAE) -2016

Conference Held at Hotel Magaji Orchid, Sheshadripuram, Bengaluru, India.

© 2016, IJERMT All Rights Reserved Page | 66

International Journal of

Emerging Research in Management &Technology

ISSN: 2278-9359 (Volume-5, Issue-5)

Behavior of CFST Infilled with FRC under Monotonic Loading 1Khalid Nayaz Khan,

2Sudha K

1 Associate Professor, civil Engineering Department, Ghousia College of Engineering, Ramanagaram, Karnataka, India

2 Master of Technology (Structural Engineering) Student, Civil Department, Ghousia College of Engineering,

Karnataka, India

Abstract— In this paper, experimental investigation on the behaviour of concrete filled steel tube infilled with

Polypropylenefibre (PPF) under monotonic loading is carried out. Here the strength of 54 Specimens was tested. The

parameters varied in this study are 1) percentage of PPF (0%, 0.2%, 0.3%, 0.4%) 2) Diameter of the hollow circular

steel tubes (33.7mm and 42.4mm) 3)L/D ratios(10,12 and 14) and 4) Grades of concrete(M20 and M30). The thickness

of steel tubes is 3.2mm which remains same for all the specimens. Polypropylene fiber concrete filled steel columns

exhibit higher strength than steel tubes filled with conventional concrete. The results show that load carrying capacity

increased with increase in percentage of polypropylene fiber and also the energy absorption capacity was enhanced.

From the hollow steel tube results it was observed that the load carrying capacity of the steel tube decreased as the D/t

ratio increased.

Keywords— Concrete filled steel tube (CFST), Polypropylene fiber(PPF)

I. INTRODUCTION

A Concrete filled steel tube (CFST) column is a structural system with excellent structural characteristics, which

is the result of combining the advantages of a steel tube and those of concrete. A CFST column is constructed by filling a

hollow rectangular or circular structural steel tube with concrete. As a structural system, a CFST column has a, excellent

earthquake-resistance, high load bearing capacity good ductility, high fire resistance and its higher stiffness which delays

the local buckling. In recent years, intensive research has resulted in advances and innovative technology of fiber such as

glass, polypropylene, carbon etc., and more basic knowledge has been gained on behavior of cement concrete containing

these fibers. The incorporation of short discrete polypropylene fiber can lead to useful improvements in the mechanical

behavior of tension of weak concrete.

II. ADVANTAGE OF USING CFST OVER ENCASED COLUMNS

Composite column combines the advantages of both structural steel & concrete, namely the speed of

construction, strength, & light weight steel, & the inherent mass, stiffness, damping, & economy of concrete. The steel

frame serves as the erection frame to complete the construction of the rest of the structure. Thus improving ductility.

Concludes that the concrete infill delays the local buckling of the steel tube. However, no increase in concrete strength

due to confinement by steel tube was observed.

Types of cfst columns

Based on the cross-sections of the steel tubes, CFST tubes are classified as circular, rectangular and square shapes

and these tubes are most commonly used ones Square Concrete encased steel (CES)

Fig 1. Types of CFST colum

a) Square Concrete encased steel (CES)

b) circular and square CFST

c) Combined both CFST and CES

d) Hollow circular and square CFST sections

e) Double skinned circular and square CFST sections

III. MATERIALS AND METHODOLOGY

CONCRETE

Design mixes are prepared using locally available Portland Pozzolana Cement (PPC), crushed granite jelly

(12.0mm down) and river sand. Mix designs of these two grades (M20, M25) of concrete are made based on the

guidelines of IS 10262-1982. The mix proportions adopted for the two grades of concrete are shown in table below.

Page 2: Behavior of CFST Infilled with FRC under Monotonic · PDF fileA Concrete filled steel tube (CFST) column is a structural system with excellent structural characteristics, ... abaqus

Khan et al., International Journal of Emerging Research in Management &Technology

ISSN: 2278-9359 (Volume-5, Issue-5)

© 2016, IJERMT All Rights Reserved Page | 67

Table 1:- Mix Proportions

Fig 2:- Casting, Curing & Testing of Cube for finding 28 days Compressive Strength

Structural Steel

In these experiment circular steel tubes of diameter 33.7 and 42.4 and thickness 3.2mm were used. For L/D ratio

of 10,12,14.

Circular CFST section for Steel:

The concrete in a circular CFST is fully confined; therefore both strength & ductility are enhanced. The steel

stress-strain relationship is modeled accordingly by approximately including in the formulation the biaxial stresses

induced by the lateral pressure of the confined concrete. When the steel reaches yield stress at which the large plastic

strains occur, part of the load resisted by the steel is transferred to the concrete core .according to van Mises yield

criteria, the longitudinal stress in the steel decreases with increasing lateral or hoop tensile stress. Therefore, the strength

of the concrete core is continuously enhanced. The enhancement is also caused by the dramatic lateral expansion of

concrete due to the development of cracks at the late stage of loading. Finally, the failure of the column occurs when the

resultant compressive force carried by the steel tube & the concrete core reaches the ultimate value.

Table: 2 Circular tubes size and corresponding L/D ,D/T ratios for yield strength 310grade

Fig 3:- Cutting & preparation of Specimen to required Length

SL

NO

Mix

designation

Proportion

C:FA:CA

W/C

ratio

% of

polypropy

lene fiber

28 Days

compressive

strength (fcu

N/mm2)

1

M20

1:1.5:3

0.45

0% 22.5

2 0.2% 27.06

3 0.3% 28.01

4 0.4% 29.28

5

M30

1:1.5:2.5

0.40

0% 31.23

6 0.2% 34.01

7 0.3% 36.23

8 0.4% 37.5

SL

NO

Diameter

(mm)

Thickness

(mm)

L/D

ratio

Length

(mm)

D/T ratio

1 33.7 3.2 10 337 10.53

2 33.7 3.2 12 405 10.53

3 33.7 3.2 14 472 10.53

4 42.4 3.2 10 424 13.25

5 42.4 3.2 12 510 13.25

6 42.4 3.2 14 594 13.25

Page 3: Behavior of CFST Infilled with FRC under Monotonic · PDF fileA Concrete filled steel tube (CFST) column is a structural system with excellent structural characteristics, ... abaqus

Khan et al., International Journal of Emerging Research in Management &Technology

ISSN: 2278-9359 (Volume-5, Issue-5)

© 2016, IJERMT All Rights Reserved Page | 68

Recron 3s polypropylene fiber

Recron 3s fiber was used as a secondary reinforcement material. It reduces shrinkage cracks and increases resistance to

water penetration, and impact. The fibers were supplied by Reliance Industry by name RECRON 3s.

Table 3: Properties of Recron 3s fibres (Polypropylene Fiber)

Fig 4: (Polypropylene Fiber)

Advantages of polypropylene fibre

Rebound loss can be reduced by 50-70% as a result of this saving of expensive mortar, cement and sand.

Time taken for plastering is reduced and work is completed faster.

Reduces cracks during plastic and hardening stage.

Reduces water seepages and protects steel in concrete from corroding and walls from corroding and walls from

damping.

IV. TEST SETUP AND PROCEDURE

The compressive strength of the specimens under monotonic loading condition is obtained using 200ton

capacity monotonic loading machine. The test conducted using 200 ton capacity monotonic loading machine (as shown

in below fig),after the column specimen are curing for 28 days. The axial load is applied slowly after fixing the

specimen tightly by careful manipulation of the loading values. The readings of the applied load, at appropriate load

increments axial shortening are recorded.

Before testing After testing

Fig 5: 200 ton capacity hydraulic monotonic loading machine

Theoritical Formulae &Calculation

The design values/capacity of CFST column was calculated using the codes: EC4, ACI (1999), AIJ (1997) & BS5400.

Eurocode4 (EC4) method, NEC4 = (AS*fy) + (AC*fc)

ACI, AIJ & Australian Standards (AS) method, NACI,AIJ,AS = (AS*fy)+0.85 (AC*fc)

BS5400 method, NBS5400 = (AS*fy )+0.675 (AC*fc)

Where,

Ac = Area of concrete infill,

As = Area of steel tube

fy= Yield strength of steel tube

fc= Compressive strength of concrete infill

V. ANALYSIS

Finite Element Method:

For many engineering problems analytical solutions are not suitable because of the complexity of the material

properties, the boundary conditions and the structure itself. The basis of the finite element method is the representation of

a body or a structure by an assemblage of subdivisions called finite elements. The Finite Element Method translates

partial differential equation problems into a set of linear algebraic equations.

Sl. No properties value

1 Length (mm) 12

2 Diameter (mm) 0.04

3 Aspect ratio(L/D) 300

4 Specific gravity 0.91

5 Tensile

strength(Mpa)

450

6 Elongation break(%) 15-25

7 Melting point (°c) 165

8 Heat resistance (°c) <130

9 Shape of fiber Special

triangle

shape

Page 4: Behavior of CFST Infilled with FRC under Monotonic · PDF fileA Concrete filled steel tube (CFST) column is a structural system with excellent structural characteristics, ... abaqus

Khan et al., International Journal of Emerging Research in Management &Technology

ISSN: 2278-9359 (Volume-5, Issue-5)

© 2016, IJERMT All Rights Reserved Page | 69

abaqus

Abaqus is a software used in FEM ( finite elment analysis) and aloso in CAD engineering .sottwarre was released in the

year 1978. In mechanical components and assemblies this software is used for modeling ,analysis and visualizing the

finite element analysis results.this software involves both pre-post processing module can be used independently.

ABAQUS it uses implicit integration scheme for finite element analysis to solve non linear system under transient loads.

This software is used in automotive and aerospace and also in industries.

This software is more useful in academic and nresearch institutions for modeling .

Software contains extensive range of material model can be used for modeling of elements

MATERIAL SPECIFICATION:

STEEL

• Material: Structural Steel Fe 310Mpa

• Young’s Modulus E=200Gpa

• Poison’s ratio v=0.3

• Density p=7800kg/m3.

CONCRETE

• Grade of Concrete: M20

• Grade of Concrete: M25

• Young’s Modulus E=22360.7Mpa

• Young’s Modulus E =2500Mpa

• Poison’s ratio v=0.16-0.3

• Density p=2400kg/m3

MODELLING AND ANALYSIS USING HYPERMESH AND ABACUS

Fig 6: Creating CFST model Fig 7: defining material properties Fig 8: segregation of element

and components

Fig 9: solid model Fig 10: meshing of CFST column

Fig 9: Buckling of column Fig 10: Mode 2 deformation

Page 5: Behavior of CFST Infilled with FRC under Monotonic · PDF fileA Concrete filled steel tube (CFST) column is a structural system with excellent structural characteristics, ... abaqus

Khan et al., International Journal of Emerging Research in Management &Technology

ISSN: 2278-9359 (Volume-5, Issue-5)

© 2016, IJERMT All Rights Reserved Page | 70

LOAD, DEFLECTION, STRESS & STRAIN VALUESOBTAINED FROM EXPERIMENT

Table -9 E

xp

no

Dia

met

er,

mm

Th

ick

nes

s, m

m

% o

f F

iber

Gra

de

Len

gth

,

mm

Are

a,

mm

2

Ult

imate

Load

, P

U K

N

Mea

sure

d

len

gth

, m

m

Ch

an

ge

in

len

gth

, m

m

Str

ain

Str

ess,

KN

/mm

2

You

ng's

Mod

ulu

s,

KN

/mm

2

1 33.7 3.2 - 337 306.62 127 344.31 7.31 0.0217 0.414 22.49

2 33.7 3.2 - 405 306.62 120 412.46 7.46 0.0184 0.391 24.18

3 33.7 3.2 - 472 306.62 115 479.64 7.64 0.0162 0.375 22.46

4 42.4 3.2 - 424 394.08 158 431.08 7.08 0.0167 0.401 28.50

5 42.4 3.2 - 509 394.08 135 516.16 7.16 0.0141 0.343 27.31

6 42.4 3.2 - 594 394.08 125 601.45 7.45 0.0125 0.317 14.72

7 33.7 3.2 0 M20 337 891.96 175 344.26 7.26 0.0215 0.196 9.42

8 33.7 3.2 0.2 M20 337 891.96 188 344.02 7.02 0.0208 0.211 10.18

9 33.7 3.2 0.3 M20 337 891.96 192 343.98 6.98 0.0207 0.215 10.57

10 33.7 3.2 0.4 M20 337 1411.95 179 343.86 6.86 0.0204 0.127 6.89

11 33.7 3.2 0 M20 405 1411.95 173 412.45 7.45 0.0184 0.123 6.71

12 33.7 3.2 0.2 M20 405 1411.95 181 412.39 7.39 0.0182 0.128 7.40

13 33.7 3.2 0.3 M20 405 891.96 186 412.02 7.02 0.0173 0.209 12.13

14 33.7 3.2 0.4 M20 405 891.96 171 411.96 6.96 0.0172 0.192 11.97

15 33.7 3.2 0 M20 472 891.96 169 479.56 7.56 0.0160 0.189 11.89

16 33.7 3.2 0.2 M20 472 1411.95 178 479.52 7.52 0.0159 0.126 8.36

17 33.7 3.2 0.3 M20 472 1411.95 182 479.12 7.12 0.0151 0.129 8.72

18 33.7 3.2 0.4 M20 472 1411.95 168 478.98 6.98 0.0148 0.119 7.19

19 42.4 3.2 0 M20 424 891.96 218 431.02 7.02 0.0166 0.244 15.00

20 42.4 3.2 0.2 M20 424 891.96 247 430.91 6.91 0.0163 0.277 17.42

21 42.4 3.2 0.3 M20 424 891.96 259 430.74 6.74 0.0159 0.290 18.65

22 42.4 3.2 0.4 M20 424 1411.95 233 430.6 6.60 0.0156 0.165 11.23

23 42.4 3.2 0 M20 509 1411.95 207 516.48 7.48 0.0147 0.147 9.87

24 42.4 3.2 0.2 M20 509 1411.95 238 516.56 7.56 0.0149 0.169 11.26

25 42.4 3.2 0.3 M20 509 891.96 250 516.62 7.62 0.0150 0.280 18.48

26 42.4 3.2 0.4 M20 509 891.96 210 516.72 7.72 0.0152 0.235 17.72

27 42.4 3.2 0 M20 594 891.96 200 601.89 7.89 0.0133 0.224 17.41

28 42.4 3.2 0.2 M20 594 1411.95 232 601.65 7.65 0.0129 0.164 13.00

29 42.4 3.2 0.3 M20 594 1411.95 246 601.51 7.51 0.0126 0.174 13.87

30 42.4 3.2 0.4 M20 594 1411.95 206 601.46 7.46 0.0126 0.146 7.90

31 33.7 3.2 0 M30 337 891.96 182 343.22 6.22 0.0185 0.204 11.44

32 33.7 3.2 0.2 M30 337 891.96 196 343.01 6.01 0.0178 0.220 12.57

33 33.7 3.2 0.3 M30 337 891.96 198 342.89 5.89 0.0175 0.222 13.17

34 33.7 3.2 0.4 M30 337 1411.95 182 342.68 5.68 0.0169 0.129 7.98

35 33.7 3.2 0 M30 405 1411.95 179 411.54 6.54 0.0161 0.127 7.41

36 33.7 3.2 0.2 M30 405 1411.95 188 411.93 6.93 0.0171 0.133 8.70

37 33.7 3.2 0.3 M30 405 891.96 192 411.2 6.20 0.0153 0.215 15.32

38 33.7 3.2 0.4 M30 405 891.96 179 410.69 5.69 0.0140 0.201 14.24

39 33.7 3.2 0 M30 472 891.96 176 478.65 6.65 0.0141 0.197 14.90

40 33.7 3.2 0.2 M30 472 1411.95 184 478.25 6.25 0.0132 0.130 9.90

41 33.7 3.2 0.3 M30 472 1411.95 190 478.21 6.21 0.0132 0.135 9.10

42 33.7 3.2 0.4 M30 472 1411.95 173 478.98 6.98 0.0148 0.123 8.31

43 42.4 3.2 0 M30 424 891.96 223 430.25 6.25 0.0147 0.250 17.88

44 42.4 3.2 0.2 M30 424 891.96 252 429.93 5.93 0.0140 0.283 20.87

45 42.4 3.2 0.3 M30 424 891.96 264 429.74 5.74 0.0135 0.296 22.33

46 42.4 3.2 0.4 M30 424 1411.95 240 429.62 5.62 0.0133 0.170 12.65

Page 6: Behavior of CFST Infilled with FRC under Monotonic · PDF fileA Concrete filled steel tube (CFST) column is a structural system with excellent structural characteristics, ... abaqus

Khan et al., International Journal of Emerging Research in Management &Technology

ISSN: 2278-9359 (Volume-5, Issue-5)

© 2016, IJERMT All Rights Reserved Page | 71

47 42.4 3.2 0 M30 509 1411.95 213 515.84 6.84 0.0134 0.151 11.55

48 42.4 3.2 0.2 M30 509 1411.95 243 515.65 6.65 0.0131 0.172 13.99

49 42.4 3.2 0.3 M30 509 891.96 258 515.26 6.26 0.0123 0.289 23.82

50 42.4 3.2 0.4 M30 509 891.96 218 515.18 6.18 0.0121 0.244 24.08

51 42.4 3.2 0 M30 594 891.96 209 600.03 6.03 0.0102 0.234 20.53

52 42.4 3.2 0.2 M30 594 1411.95 241 600.78 6.78 0.0114 0.171 15.22

53 42.4 3.2 0.3 M30 594 1411.95 253 600.66 6.66 0.0112 0.179 16.22

54 42.4 3.2 0.4 M30 594 1411.95 213 600.56 6.56 0.0110 0.151 13.66

GRAPHICAL REPRESENTATION OF LOAD, DEFLECTION, STRESS & STRAIN VALUES OBTAINED

FROM EXPERIMENT

Load v/s Deflection graph for two different Diameter (d1 and d2), Thickness (t1), and % of polypropylene Fiber (0%,

0.2%, 0.3% and 0.4%) for M20 Grade of Concrete filled CFST.

Load v/s Deflection graph for two different Diameter (d1 and d2), Thickness (t1), and % of polypropylene Fiber (0%,

0.2%, 0.3% and 0.4%) for M20 Grade of Concrete filled CFST.

Load V/S Deflection Graph For Three Different Diameter D1, D2, Thickness (T1, T2, And T3), For Hollow Steel Tube

Page 7: Behavior of CFST Infilled with FRC under Monotonic · PDF fileA Concrete filled steel tube (CFST) column is a structural system with excellent structural characteristics, ... abaqus

Khan et al., International Journal of Emerging Research in Management &Technology

ISSN: 2278-9359 (Volume-5, Issue-5)

© 2016, IJERMT All Rights Reserved Page | 72

stress v/s strain graph for three different diameter d1 and d2 , thickness t1, and % of polypropylene Fiber (0%, 0.2%,

0.3% and 0.4%) for M20 Grade of Concrete filled CFST

stress v/s strain graph for three different diameter d1 and d2, thickness t, for hollow tube.

COMPARISION OF EXPERIMENTAL, THEORITICAL, ANALYTICAL RESULTS &GRAPHICAL

REPRESENTATION

TY

PE

SL

NO

Dia

met

er,

mm

Th

ick

nes

s, m

m

% o

f F

iber

Gra

de

Len

gth

,

mm

Are

a,

mm

2

(EX

P)U

ltim

ate

Load

, P

U K

N

EU

RO

CO

DE

4

NE

C4=

AS

*fy

+A

C*fc

AC

I, A

IJ &

AS

met

hod

,

NA

CI,

AIJ

,AS

=A

S*fy

+0.8

5*A

C*f

c B

S5400 m

eth

od

,

NB

S5400=

AS

*fy

+0.6

75*A

C*fc

(AN

AL

YS

IS)

Ult

imate

Load

, P

U K

N

HO

LL

OW

1 33.7 3.2 - 337 891.52 127 95.05 95.05 95.05 168

2 33.7 3.2 - 405 891.52 120 95.05 95.05 95.05 159

3 33.7 3.2 - 472 891.52 115 95.05 95.05 95.05 155

4 42.4 3.2 - 424 1411.24 158 122.16 122.16 122.16 193

5 42.4 3.2 - 509 1411.24 135 122.16 122.16 122.16 187

Page 8: Behavior of CFST Infilled with FRC under Monotonic · PDF fileA Concrete filled steel tube (CFST) column is a structural system with excellent structural characteristics, ... abaqus

Khan et al., International Journal of Emerging Research in Management &Technology

ISSN: 2278-9359 (Volume-5, Issue-5)

© 2016, IJERMT All Rights Reserved Page | 73

6 42.4 3.2 - 594 1411.24 125 122.16 122.16 122.16 172 M

20

GA

RD

E

7 33.7 3.2 0 M20 337 891.52 175 108.17 106.19 103.89 183

8 33.7 3.2 0.2 M20 337 891.52 188 110.83 108.46 105.69 198

9 33.7 3.2 0.3 M20 337 891.52 192 111.74 109.23 106.30 212

10 33.7 3.2 0.4 M20 337 891.52 179 112.58 109.95 106.87 188

11 33.7 3.2 0 M20 405 891.52 173 108.17 106.19 103.89 176

12 33.7 3.2 0.2 M20 405 891.52 181 110.83 108.46 105.69 189

13 33.7 3.2 0.3 M20 405 891.52 186 111.74 109.23 106.30 209

14 33.7 3.2 0.4 M20 405 891.52 171 112.58 109.95 106.87 181

15 33.7 3.2 0 M20 472 891.52 169 108.17 106.19 103.89 171

16 33.7 3.2 0.2 M20 472 891.52 178 110.83 108.46 105.69 181

17 33.7 3.2 0.3 M20 472 891.52 182 111.74 109.23 106.30 198

18 33.7 3.2 0.4 M20 472 891.52 168 112.58 109.95 106.87 176

19 42.4 3.2 0 M20 424 1411.24 218 144.99 141.56 137.55 242

20 42.4 3.2 0.2 M20 424 1411.24 247 149.62 145.49 140.68 268

21 42.4 3.2 0.3 M20 424 1411.24 259 151.20 146.84 141.74 283

22 42.4 3.2 0.4 M20 424 1411.24 233 152.67 148.09 142.74 265

23 42.4 3.2 0 M20 509 1411.24 207 144.99 141.56 137.55 239

24 42.4 3.2 0.2 M20 509 1411.24 238 149.62 145.49 140.68 258

25 42.4 3.2 0.3 M20 509 1411.24 250 151.20 146.84 141.74 262

26 42.4 3.2 0.4 M20 509 1411.24 210 152.67 148.09 142.74 261

27 42.4 3.2 0 M20 594 1411.24 200 144.99 141.56 137.55 230

28 42.4 3.2 0.2 M20 594 1411.24 232 149.62 145.49 140.68 251

29 42.4 3.2 0.3 M20 594 1411.24 246 151.20 146.84 141.74 258

30 42.4 3.2 0.4 M20 594 1411.24 206 152.67 148.09 142.74 226

M30 G

AR

DE

31 33.7 3.2 0 M30 337 891.52 182 113.70 110.89 107.62 218

32 33.7 3.2 0.2 M30 337 891.52 196 114.93 111.94 108.45 232

33 33.7 3.2 0.3 M30 337 891.52 198 115.77 112.66 109.02 249

34 33.7 3.2 0.4 M30 337 891.52 182 116.81 113.54 109.73 210

35 33.7 3.2 0 M30 405 891.52 179 113.70 110.89 107.62 198

36 33.7 3.2 0.2 M30 405 891.52 188 114.93 111.94 108.45 211

37 33.7 3.2 0.3 M30 405 891.52 192 115.77 112.66 109.02 226

38 33.7 3.2 0.4 M30 405 891.52 179 116.81 113.54 109.73 189

39 33.7 3.2 0 M30 472 891.52 176 113.70 110.89 107.62 192

M30 G

AR

DE

40 33.7 3.2 0.2 M30 472 891.52 184 114.93 111.94 108.45 216

41 33.7 3.2 0.3 M30 472 891.52 190 115.77 112.66 109.02 229

42 33.7 3.2 0.4 M30 472 891.52 173 116.81 113.54 109.73 190

43 42.4 3.2 0 M30 424 1411.24 223 154.61 149.73 144.0 269

44 42.4 3.2 0.2 M30 424 1411.24 252 156.75 151.56 145.49 275

45 42.4 3.2 0.3 M30 424 1411.24 264 158.22 152.80 146.48 299

46 42.4 3.2 0.4 M30 424 1411.24 240 160.03 154.34 147.70 259

47 42.4 3.2 0 M30 509 1411.24 213 154.61 149.73 144.04 256

48 42.4 3.2 0.2 M30 509 1411.24 243 156.75 151.56 145.49 269

49 42.4 3.2 0.3 M30 509 1411.24 258 158.22 152.80 146.48 282

50 42.4 3.2 0.4 M30 509 1411.24 218 160.03 154.34 147.70 223

51 42.4 3.2 0 M30 594 1411.24 209 154.61 149.73 144.04 234

52 42.4 3.2 0.2 M30 594 1411.24 241 156.75 151.56 145.49 246

53 42.4 3.2 0.3 M30 594 1411.24 253 158.22 152.80 146.48 258

54 42.4 3.2 0.4 M30 594 1411.24 213 160.03 154.34 147.70 214

Comparison of Experimental, Theoretical & Analytical Ultimate Load “Pu” values for three different diameter (d1=33.7

and d2=42.4) for thickness ( t=3.2) & different % of polypropylene fiber (0%, 0.2%, 0.3% & 0.4%) for CFST of M20

Grade.

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Khan et al., International Journal of Emerging Research in Management &Technology

ISSN: 2278-9359 (Volume-5, Issue-5)

© 2016, IJERMT All Rights Reserved Page | 74

Comparison of Experimental, Theoretical & Analytical Ultimate Load “Pu” values for three different diameter (d1=33.7

and d2=42.4) for thickness ( t=3.2) & different % of polypropylene fiber (0%, 0.2%, 0.3% & 0.4%) for CFST of M30

Grade.

Comparison of Experimental, Theoretical & Analytical Ultimate Load “Pu” values for three different diameter (d1=33.7,

d2=42.4,) &thickness ( t=3.2) for Hollow Steel Tube.

33.7 33.7 33.7 42.4

length 337 405 472 424 509 594

pu(KN) 95.05 95.05 95.05 122.16 122.16 122.16

t(mm) 3.2 3.2 3.2 3.2 3.2 3.2

0

200

400

600

800

Load

, K

N

Pu V/S dia for different length of column

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Khan et al., International Journal of Emerging Research in Management &Technology

ISSN: 2278-9359 (Volume-5, Issue-5)

© 2016, IJERMT All Rights Reserved Page | 75

VI. CONCLUSIONS

1. As length increased, load carrying capacity decreases.

2. As grade of concrete increased, load carrying capacity increased for a particular Length of the column by 5 to 8%.

3. As percentage of fiber increased, load carrying capacity (Pu ) increased for 0.2%,0.3% whereas decreased when

percentage increased 0.4% i.e. optimum percentage May be in the range of 0.2% to 0.3% for particular length and

grade.

4. From experimental results showed that the important factors affecting the load-deformation behavior are; Geometric

actors like member size, thickness of steel tube, slenderness, D/t ratio of the tube, Grades of concrete, Percentage of

fiber added.

5. The effect of cross sectional area has more influence on the ultimate load bearing capacity of the CFST than the

parameters like thickness, length and % of fiber.

6. Area of the steel tube has the most significant effect on both the ultimate axial load capacity and corresponding axial

shortening of CFST.

7. Increase in diameter of the steel tube increases the strength of the CFST tube.

8. Polypropylene fiber reinforced concrete increases of the ductility of the CFST tube.

REFERENCE

[1] Ou, Z.Chen, B.Hsieh, K.Halling and Barr, P.(2011). “Experimental and analytical Investigation of Concrete

Filled Steel Tubular Column.” Journals of Structural engineering,

[2] J. Zeghichea K. Chaouib, “An experimental behaviour of concrete-filled steel tubular columns Journal of

Constructional Steel Research, Volume 61, Issue 1, January 2005,

[3] Bing Chen , Xiao Liu, Siping Li, “Performance investigation of square concrete-filled steel tube

columns”,Journal of Wuhan University of Technology-Mater.

[4] Zhanfei Wang, Yamao Toshitaka, “Ultimate strength and ductility of stiffened steel tubular bridge piers”,

International Journal of Steel Structures,

[5] Thanuja H.P, E.Ramesh Babu, Dr N S Kumar, “A Study on Behaviour of Circular Stiffened Hollow Steel

Column Filled With Self Compacting Concrete Under Monotonic Loading” INDIAN JOURNAL OF APPLIED

RESEARCH,

[6] Vinutha K, Dr. N. S. Kumar, “Behaviour Of Stub Stainless Steel Square Hollow Sections Subjected To

Monotonic Loading”, INTERNATIONAL JOURNAL OF INNOVATIVE RESEARCH.