STRENGTH AND DUCTILITY OF AXIALLY

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25 Νοε 2013 (πριν από 3 χρόνια και 4 μήνες)

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STRENGTH AND DUCTILITY OF AXIALLY
LOADED RC SHORT COLUMN CONFINED
WITH CFRP AND GFRP

Haider Osamah Al
-
Karaghool

Supervised by: Dr. Adil K. Al
-
Tamimi

Dr. Jamal A. Abdalla

Thesis Defense

OUTLINE


Introduction


Research Objectives and Significance


Literature Review


Experimental Program


Discussion of Results


Conclusion

Introduction

Introduction

Research

Objective &
Significance

Literature
Review

Experimental
Setup

Discussion of
Results

Conclusion

The need for safe building!!!

Construction Industry vs. Technology


Dead Load, Live Load, Load path, New building requirements

Change

in the structure


Corrosion, Fatigue, Design Errors, Hazardous Factors

Degradation of a structure

New Building vs. Old Buildings

Environ.
Friendly

Energy
Conservative

Less Carbon
Footprint


Enhanced Life
Expectancy

Introduction

Fiber Reinforced Polymer
(FRP)
-
Defenition

A

composite material

made of a

polymer

matrix reinforced
with fibres.

Types

AFRP

CFRP

GFRP

Introduction

Research

Objective &
Significance

Literature
Review

Experimental
Setup

Discussion of
Results

Conclusion

Introduction

Fiber Reinforced Polymer
(FRP)
-
Properties

Criterion

Aramid

Carbon

Glass

Young Modulus

Good

Very Good

Adequate

Tensile Strength

Very Good

Very Good

Very Good

Compressive Strength

Inadequate

Very Good

Good

Long
-
term Behavior

Good

Excellent

Very Good

Stiffness

Good

Very Good

Adequate

Fatigue Behavior

Good

Excellent

Adequate

Bulk Density

Excellent

Good

Adequate

Alkaline Resistance

Good

Very Good

Inadequate

Price

Adequate

Adequate

Very Good

Introduction

Research

Objective &
Significance

Literature
Review

Experimental
Setup

Discussion of
Results

Conclusion

Introduction

Fiber Reinforced Polymer
(FRP)
-
Properties

Material

Density (kg/m3)

Tensile Modules

(GPa
)

Tensile strength (MPa)

AFRP

1050
-
1250

20
-
125

1000
-
1800

CFRP

1600
-
1900

120
-
250

1200
-
2250

GFRP

1600
-
1800

20
-
55

400
-
1800

Introduction

Research

Objective &
Significance

Literature
Review

Experimental
Setup

Discussion of
Results

Conclusion

Introduction

Fiber Reinforced Polymer
(FRP)
-
Advantages

Introduction

Research

Objective &
Significance

Literature
Review

Experimental
Setup

Discussion of
Results

Conclusion

Advantages

CFRP

GFRP

High

Tensile strength

Low cost

High Tensile modulus

High tensile strength

High

fatigue resistance

High chemical resistance

High

insulation

Introduction

Fiber Reinforced Polymer
(FRP)
-
Disadvantages

Introduction

Research

Objective &
Significance

Literature
Review

Experimental
Setup

Discussion of
Results

Conclusion

Disadvantages

CFRP

GFRP

High

cost

Low

Tensile Modulus

High brittleness

High

hardness

High

conductivity

Low

fatigue resistance

Low abrasion resistance

Research Objectives


Study the behavior of
Normal

designed RC column when strengthened
with CFRP or GFRP in one or two layers.


Study the behavior of
Under

designed RC columns when strengthened
with CFRP or GFRP in one or two layers


Compare the behavior of strengthened under designed RC columns with
the non
-
strengthened normal designed RC column.

Introduction

Research

Objective &
Significance

Literature
Review

Experimental
Setup

Discussion of
Results

Conclusion

Research Objectives


Strength (Load Capacity)


Ductility

Behavior as


Type of Material


Number of Layers

Parameters

involved

Introduction

Research

Objective &
Significance

Literature
Review

Experimental
Setup

Discussion of
Results

Conclusion

Research Significance

Testing strengthened RC
column with CFRP or
GFRP

Find

the ideal solution
that would replace the
idea of the demolishing
the structure

Introduction

Research

Objective &
Significance

Literature
Review

Experimental
Setup

Discussion of
Results

Conclusion

Literature Review

Introduction

Research

Objective &
Significance

Literature
Review

Experimental
Setup

Discussion of
Results

Conclusion


A
.

Mirmiran
,

M
.

Shahawy
,

M
.

Samaan
,

H
.

El

Echary
,

J
.

C
.

Mastrapa
,

and

O
.

Pico

(
1998
)


Studied

the

effect

of

Shape,

Length,

and

Bond

between

the

concrete

and

the

jacket
.



Eccentric

Loading


More

than

100

samples

were

casted

(Cylinders

and

Square

columns)


GFRP


Conclusion


Square

sections

are

less

effective

than

Circular

sections


Effect

of

length

to
-
diameter

ratios

within

the

range

of

2
:
1

and

5
:
1

is

not

significant

for

either

strength

or

ductility

of

the

section


Adhesive

bond

does

not

effect

load
-
carrying

capacity

of

FRP
-
confined

concrete
.


Literature Review

Introduction

Research

Objective &
Significance

Literature
Review

Experimental
Setup

Discussion of
Results

Conclusion


P
.

Rochette

and

P
.

Labossiere

(
2000
)


Studied

the

behaviour

reinforced

concrete

columns

reinforced

confined

with

composites


Axial

Loading


More

than

40

specimens


CFRP

and

GFRP


Conclusion


Confinement

of

Circular

is

more

effective

than

Square

and

Rectangular
.


The

Radius

of

the

round

corner

is

directly

proportional

with

the

effective

of

the

confinement
.



Excessive

confinement

will

lead

to

very

sudden

and

destructive

compressive

failure,

which

must

be

avoided
.



Literature Review

Introduction

Research

Objective &
Significance

Literature
Review

Experimental
Setup

Discussion of
Results

Conclusion


Omar

Chaallal
,

Mohsen

Shahawy
,

and

Hunzer

Hassan

(
2003
)


Study

the

effectiveness

of

external

wrapping

for

concrete

columns



Parameters

involved
:


Concrete

strength


Aspect

ratio

of

cross

section


Number

of

FRP

layers


Axial

Loading


Square

and

Rectangular

section


CFRP


30

samples



Conclusion



CFRP

confinement

showed

improvement

in

strength

and

ductility


Compressive

strength

is

inversely

proportional

with

the

axial

and

transverse

strain
.


the

gain

in

the

compressive

strength

depends

on

the

ratio

of

the

stiffness

of

the

FRP

jacket

in

the

lateral

direction

to

the

axial

stiffness

of

the

column

Literature Review

Introduction

Research

Objective &
Significance

Literature
Review

Experimental
Setup

Discussion of
Results

Conclusion


Hua

Wei,

Zhimin

Wu,

Xia

Guo
,

and

Fumin

Yi

(
2009
)


Investigate

the

mechanical

behaviour

of

columns

with

partial

deteriorated

strength

and

to

evaluate

the

availability

of

the

partial

confinement
.


Parameters

involved
:


Concrete

strength


Number

of

wrapping

layers


Plain

vs
.

Reinforced

concrete


Axial

Loading


Square

section


CFRP


30

samples

(
15

Plain

vs
.

15

Reinforced)


Conclusion



Partial

confinement

in

deteriorated

regions

with

CFRP

can

significantly

enhance

the

performance

of

columns
.


The

ductility

of

confined

specimens

was

enhanced

significantly

compared

to

the

partial

deteriorated

column

as

well

as

the

original

column
.

Experimental Setup

Theoretical Analysis

Concrete Mix Design

Strain Gauge Fixing

Epoxy Preparation

Column Preparation

Proposed Matrix

Introduction

Research

Objective &
Significance

Literature
Review

Experimental
Setup

Discussion of
Results

Conclusion

Experimental Setup

Theoretical Analysis

ACI 318

Introduction

Research

Objective &
Significance

Literature
Review

Experimental
Setup

Discussion of
Results

Conclusion

Experimental Setup

Theoretical Analysis

ACI 318

Gross
Area (150x150

mm)

22500

mm
2

Steel
Area (4 #10)

1257

mm
2

Concrete
Comp
ressive Strength (28 Days)

35

MPa

Steel Yield
Strength

420

MPa

Strength
Reduction Factor (ties)

0.85

-

Load

790

kN

Introduction

Research

Objective &
Significance

Literature
Review

Experimental
Setup

Discussion of
Results

Conclusion

Experimental Setup

Theoretical Analysis

Introduction

Research

Objective &
Significance

Literature
Review

Experimental
Setup

Discussion of
Results

Conclusion

Normal Design

Under Design

Experimental Setup

Theoretical Analysis

Introduction

Research

Objective &
Significance

Literature
Review

Experimental
Setup

Discussion of
Results

Conclusion

Normal Design

Under Design

Experimental Setup

Theoretical Analysis

Introduction

Research

Objective &
Significance

Literature
Review

Experimental
Setup

Discussion of
Results

Conclusion

Experimental Setup

Concrete Mix Design

ACI 211

Material

Cement

Water

Coarse Aggregate

Fine Aggregate

Ratios

1

0.46

1.6

2.91

S.G

3.14

1

2.61

2.57

Water Absorption

Coarse

Aggregate

Fine
Aggregate

Percentage

0.5

1.0

Aggregate

Coarse

Fine

Material

20mm

10mm

Crushed Sand

Dune Sand

Percentage

60

40

65

35

Introduction

Research

Objective &
Significance

Literature
Review

Experimental
Setup

Discussion of
Results

Conclusion

Experimental Setup

Concrete Mix Design

Introduction

Research

Objective &
Significance

Literature
Review

Experimental
Setup

Discussion of
Results

Conclusion

Experimental Setup

Strain Gauge Fixing

Introduction

Research

Objective &
Significance

Literature
Review

Experimental
Setup

Discussion of
Results

Conclusion

Experimental Setup

Epoxy Preparation
-
Primer

Introduction

Research

Objective &
Significance

Literature
Review

Experimental
Setup

Discussion of
Results

Conclusion



Low
-
viscous

material

used

to

fill

the

pores

on

the

concrete

specimen

surface

in

order

to

ensure

full

bonding

between

the

FRP

composite

and

the

concrete

surface


Two parts : Part A : Base


Part B : Hardener

Experimental Setup

Epoxy Preparation
-
Primer

Introduction

Research

Objective &
Significance

Literature
Review

Experimental
Setup

Discussion of
Results

Conclusion

Property

Test

Method

Value

Component

-

Two:

Part A
-
base

Part B
-
Hardener

Form

-

Liquid

Color

-

Clear I Pale Yellow

Potlife

-

70+/
-

10min

Service Temperature

-

+5 C
o

to +75 C
o

Surface Drying Time

ASTM D2939

6
-
8 hours

Bond Strength

ASTM D4541

Concrete Failure

Experimental Setup

Epoxy Preparation
-
Saturant

Introduction

Research

Objective &
Significance

Literature
Review

Experimental
Setup

Discussion of
Results

Conclusion


Medium
-
viscous

material

used

as

a

bonding

agent

between

the

concrete

surface

and

the

FRP

material


Two parts : Part A : Base


Part B : Hardener

Experimental Setup

Epoxy Preparation
-
Saturant

Introduction

Research

Objective &
Significance

Literature
Review

Experimental
Setup

Discussion of
Results

Conclusion

Property

Test

Method

Value

Component

-

Two:

Part A
-
Base

Part B
-
Hardener

Form

-

Liquid

Color

-

Grey/White/Light Blue

Potlife

-

45
-
60 min

Service Temperature

-

+5 C
o

to +75 C
o

Bond Strength

ASTM D4541

> 2 N/mm
2

Compressive Strength

BS 6319
-
2

70 N/mm
2

at 7 days

Experimental Setup

Column Preparation

Introduction

Research

Objective &
Significance

Literature
Review

Experimental
Setup

Discussion of
Results

Conclusion

After

125 mm

125 mm

750 mm

500 mm

Before

R = 25 mm

Experimental Setup

Proposed Matrix

Introduction

Research

Objective &
Significance

Literature
Review

Experimental
Setup

Discussion of
Results

Conclusion

NC11

N2

N3

U1

U2

U3

NC21

NC22

NC23

UC21

UC22

UC23

N
1

NC12

NC13

UC11

UC12

UF13

NG11

NG12

NG13

UG11

UG12

UC13

UF23

NG21

NG22

NG23

UG21

UG22

N:

Standard

U:

Under

C:

CFRP

G:

GFRP

First

Number:

# of Wraps

Second Number

:

Sample

Number

Introduction

Research

Objective &
Significance

Literature
Review

Experimental
Setup

Discussion of
Results

Conclusion

Discussion of Results

N Group

#

P (KN)

∆u

∆y

μ


N1

937.859

5.258

4.430

1.187

N2

803.907

3.975

3.391

1.172

N3

843.165

4.302

3.348

1.285

Average

861.644

4.512

3.723

1.215

Introduction

Research

Objective &
Significance

Literature
Review

Experimental
Setup

Discussion of
Results

Conclusion

Discussion of Results

NC1 Group

#

P (KN)

∆u

∆y

μ


NC11

917

6.266

4.765

1.315

NC12

1002

4.886

4.143

1.179

NC13

910

5.007

4.090

1.224

Average

943

5.386

4.332

1.240

Introduction

Research

Objective &
Significance

Literature
Review

Experimental
Setup

Discussion of
Results

Conclusion

Discussion of Results

NC2 Group

#

P (KN)

∆u

∆y

μ


NC21

1014

5.701

4.212

1.353

NC22

1010

4.952

4.076

1.215

NC23

1019

5.437

3.956

1.374

Average

1014

5.363

4.081

1.314

Introduction

Research

Objective &
Significance

Literature
Review

Experimental
Setup

Discussion of
Results

Conclusion

Discussion of Results

NG1 Group

#

P (KN)

∆u

∆y

μ


NG11

977

5.639

4.438

1.271

NG12

926

8.147

5.765

1.413

NG13

890

6.650

4.786

1.390

Average

931

6.812

4.996

1.358

Introduction

Research

Objective &
Significance

Literature
Review

Experimental
Setup

Discussion of
Results

Conclusion

Discussion of Results

NG2 Group

#

P (KN)

∆u

∆y

μ


NG21

1044

7.178

3.543

2.026

NG22

1141

7.489

3.139

2.386

NG23

1035

4.656

4.040

1.152

Average

1073

6.441

3.574

1.855

Introduction

Research

Objective &
Significance

Literature
Review

Experimental
Setup

Discussion of
Results

Conclusion

Discussion of Results

U Group

#

P (KN)

∆u

∆y

μ


U1

658

3.084

2.498

1.235

U2

546

4.329

3.407

1.271

U3

742

3.466

3.424

1.012

Average

649

3.626

3.109

1.173

Introduction

Research

Objective &
Significance

Literature
Review

Experimental
Setup

Discussion of
Results

Conclusion

Discussion of Results

UC1 Group

#

P (KN)

∆u

∆y

μ


UC11

871

4.163

3.702

1.125

UC12

912

8.995

6.745

1.334

UC13

893

6.245

5.342

1.169

Average

892

6.468

5.263

1.209

Introduction

Research

Objective &
Significance

Literature
Review

Experimental
Setup

Discussion of
Results

Conclusion

Discussion of Results

UC2 Group

#

P (KN)

∆u

∆y

μ


UC21

1035

7.655

6.706

1.142

UC22

1053

6.629

5.131

1.292

UC23

1035

6.437

5.362

1.200

Average

1041

6.907

5.733

1.211

Introduction

Research

Objective &
Significance

Literature
Review

Experimental
Setup

Discussion of
Results

Conclusion

Discussion of Results

UG1 Group

#

P (KN)

∆u

∆y

μ


UG11

845

5.529

4.890

1.131

UG12

892

6.523

5.023

1.299

UG13

831

7.612

5.826

1.307

Average

856

6.555

5.246

1.245

Introduction

Research

Objective &
Significance

Literature
Review

Experimental
Setup

Discussion of
Results

Conclusion

Discussion of Results

UG2 Group

#

P (KN)

∆u

∆y

μ


UG21

938

5.601

4.446

1.260

UG22

940

9.401

7.598

1.237

UG23

997

6.014

4.478

1.343

Average

959

7.005

5.507

1.280

Introduction

Research

Objective &
Significance

Literature
Review

Experimental
Setup

Discussion of
Results

Conclusion

Discussion of Results

Transverse Strain Gauges

#

Transverse

#

Transverse

#

Transverse

#

Transverse

#

Transverse

N1

-
3.47E
-
04

NC11

-

NC21

-

NG11

-

NG21

-
5.40E
-
05

N2

-
3.45E
-
04

NC12

-
2.38E
-
04

NC22

-
5.00E
-
05

NG12

-
3.32E
-
04

NG22

-
6.00E
-
05

N3

-
6.49E
-
04

NC13

-
3.10E
-
04

NC23

-
4.00E
-
05

NG13

-
2.50E
-
04

NG23

-
4.60E
-
05

Average

-
4.47E
-
04

Average

-
2.74E
-
04

Average

-
4.50E
-
05

Average

-
2.91E
-
04

Average

-
5.33E
-
05

#

Transverse

#

Transverse

#

Transverse

#

Transverse

#

Transverse

U1

-

UC11

-
7.40E
-
04

UC21

-
4.19E
-
04

UG11

-

UG21

-
3.19E
-
04

U2

-
2.50E
-
04

UC12

-
2.33E
-
04

UC22

-
3.68E
-
04

UG12

-
5.00E
-
04

UG22

-
1.66E
-
04

U3

-
3.10E
-
04

UC13

-
1.90E
-
04

UC23

-
1.00E
-
04

UG13

-
3.00E
-
04

UG23

-

Average

-
2.80E
-
04

Average

-
3.88E
-
04

Average

-
2.96E
-
04

Average

-
4.00E
-
04

Average

-
2.43E
-
04

Introduction

Research

Objective &
Significance

Literature
Review

Experimental
Setup

Discussion of
Results

Conclusion

Discussion of Results

Load and Ductility Values

#

P (KN)

∆u

∆y

μ


#

P (KN)

∆u

∆y

μ


N1

938

5.258

4.430

1.187

U1

658

3.084

2.498

1.235

N2

804

3.975

3.391

1.172

U2

546

4.329

3.407

1.271

N3

843

4.302

3.348

1.285

U3

742

3.466

3.424

1.012

Average

862

4.512

3.723

1.215

Average

649

3.626

3.109

1.173

NC11

917

6.266

4.765

1.315

UC11

871

4.163

3.702

1.125

NC12

1002

4.886

4.143

1.179

UC12

912

8.995

6.745

1.334

NC13

910

5.007

4.090

1.224

UC13

893

6.245

5.342

1.169

Average

943

5.386

4.332

1.240

Average

892

6.468

5.263

1.209

NC21

1014

5.701

4.212

1.353

UC21

1035

7.655

6.706

1.142

NC22

1010

4.952

4.076

1.215

UC22

1053

6.629

5.131

1.292

NC23

1019

5.437

3.956

1.374

UC23

1035

6.437

5.362

1.200

Average

1014

5.363

4.081

1.314

Average

1041

6.907

5.733

1.211

NG11

977

5.639

4.438

1.271

UG11

845

5.529

4.890

1.131

NG12

926

8.147

5.765

1.413

UG12

892

6.523

5.023

1.299

NG13

890

6.650

4.786

1.390

UG13

831

7.612

5.826

1.307

Average

931

6.812

4.996

1.358

Average

856

6.555

5.246

1.245

NG21

1044

7.178

3.543

2.026

UG21

938

5.601

4.446

1.260

NG22

1141

7.489

3.139

2.386

UG22

940

9.401

7.598

1.237

NG23

1035

4.656

4.040

1.152

UG23

997

6.014

4.478

1.343

Average

1073

6.441

3.574

1.855

Average

959

7.005

5.507

1.280

Introduction

Research

Objective &
Significance

Literature
Review

Experimental
Setup

Discussion of
Results

Conclusion

Discussion of Results

Comparisons
-

N Group

Type

N

NC1

NC2

NG1

NG2

Load (KN)

862

943

1073

931

1014

% Diff

-

9.44%

24.56%

8.06%

17.68%

∆u (mm)

4.512

5.386

5.363

6.812

6.441

∆y (mm)

3.723

4.332

4.081

4.438

3.574

μ


1.215

1.240

1.314

1.358

1.855

%Diff

-

2.06%

8.15%

11.77%

52.67%

Transverse

-
4.47E
-
04

-
2.74E
-
04

-
4.50E
-
05

-
2.91E
-
04

-
5.33E
-
05


%Diff

-

-
38.702%

-
89.933%

-
34.899%

-
88.069%

Introduction

Research

Objective &
Significance

Literature
Review

Experimental
Setup

Discussion of
Results

Conclusion

Discussion of Results

Comparisons
-

U Group

Type

U

UC1

UC2

UG1

UG2

Load (KN)

649

892

1041

856

959

% Diff

-

37.54%

60.49%

32.02%

47.80%

∆u (mm)

3.626

6.468

6.907

6.555

7.005

∆y (mm)

3.109

5.263

5.733

5.246

5.507

μ


1.173

1.209

1.211

1.245

1.280

%Diff

-

3.07%

3.24%

6.14%

9.12%

Transverse

-
2.80E
-
04

-
3.88E
-
04

-
2.96E
-
04

-
4.00E
-
04

-
2.43E
-
04



-

38.452%

5.595%

42.857%

-
13.393%

Introduction

Research

Objective &
Significance

Literature
Review

Experimental
Setup

Discussion of
Results

Conclusion

Discussion of Results

Comparisons
-

N vs. U
Group

Type

N

UC1

UC2

UG1

UG2

Load (KN)

862

892

1041

856

959

% Diff

-

3.52%

20.80%

-
0.63%

11.25%

∆u (mm)

4.512

6.468

6.907

6.555

7.005

∆y (mm)

3.723

5.263

5.733

5.246

5.507

μ


1.215

1.209

1.211

1.245

1.280

%Diff

-

-
0.49%

-
0.33%

2.47%

5.35%

Transverse

-
5.33E
-
05

-
3.88E
-
04

-
2.96E
-
04

-
4.00E
-
04

-
2.43E
-
04



-

626.88%

454.38%

650.00%

354.69%

Introduction

Research

Objective &
Significance

Literature
Review

Experimental
Setup

Discussion of
Results

Conclusion

Discussion of Results

Mode of Failure

Column

Type of Failure

Position

Column

Type of
Failure

Position

NC11

Delamination

Top

UC11

Delamination

Top + Middle

NC12

Delamination

Top

UC12

Delamination

Top + Middle

NC13

Delamination

Top

UC13

Delamination

Top + Middle

NC21

Delamination

Top

UC21

Delamination

Top

NC22

Delamination

Top

UC22

Delamination

Top

NC23

Debonding

Top

UC23

Delamination

Top

NG11

Debonding

Middle

UG11

Debonding

Top + Middle

NG12

Debonding

Top

UG12

Debonding

Middle

NG13

Debonding

Middle

UG13

Delamination

Top

NG21

Debonding

Top

UG21

Delamination

Top

NG22

Debonding

Middle

UG22

Debonding

Top + Middle

NG23

Debonding

Top

UG23

Debonding

Top

Introduction

Research

Objective &
Significance

Literature
Review

Experimental
Setup

Discussion of
Results

Conclusion

Conclusion


The external confinement with CFRP or GFRP materials has increased the load and
ductility of the normal and under designed specimen under axial loading.


The results of the materials tested showed that CFRP materials has produced the
largest lateral confinement pressure to column specimens. However, GFRP materials
has produced enhancements in ductility.


Excessive confinement will lead to very sudden and destructive compressive failures,
which must be avoided.


Externally confined concrete column could undergo large deformation without
complete failure.


Introduction

Research

Objective &
Significance

Literature
Review

Experimental
Setup

Discussion of
Results

Conclusion

Special Thanks


Dr. Adil Al
-
Tamimi


Dr. Jamal Abdalla, Dr. Sherif Yehia, and Dr. Bassil Darras


Eng. Arshi Faridi


Eng. Ahmed Gadhban

Eng . Assia
Lasfer

and thank you for listening …