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

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

GFRP

Haider Osamah Al-KaraghoolSupervised 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

IntroductionResearch

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



Literature Review

Experimental Setup


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



Literature Review

Experimental Setup


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



Literature Review

Experimental Setup


Introduction Fiber Reinforced Polymer (FRP)-Advantages



Literature Review

Experimental Setup


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



Literature Review

Experimental Setup


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.



Literature Review

Experimental Setup


Research Objectives

• Strength (Load Capacity)• Ductility

Behavior as

• Type of Material• Number of Layers

Parameters involved



Literature Review

Experimental Setup


Research Significance

Testing strengthened RC column with CFRP or

GFRP

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

the structure



Literature Review

Experimental Setup


Literature Review



Literature Review

Experimental Setup


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



Literature Review

Experimental Setup


P. Rochette and P. Labossiere (2000)Studied the behaviour reinforced concrete columns reinforced confined with

compositesAxial LoadingMore than 40 specimensCFRP and GFRP

ConclusionConfinement 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



Literature Review

Experimental Setup


Omar Chaallal, Mohsen Shahawy, and Hunzer Hassan (2003)Study the effectiveness of external wrapping for concrete columns Parameters involved:

Concrete strengthAspect ratio of cross sectionNumber of FRP layers

Axial LoadingSquare and Rectangular sectionCFRP30 samples

Conclusion CFRP confinement showed improvement in strength and ductilityCompressive 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



Literature Review

Experimental Setup


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 strengthNumber of wrapping layersPlain vs. Reinforced concrete

Axial LoadingSquare sectionCFRP30 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



Literature Review

Experimental Setup


Experimental Setup Theoretical Analysis

ACI 318



Literature Review

Experimental Setup



ACI 318

Gross Area (150x150 mm) 22500 mm2

Steel Area (4 #10) 1257 mm2

Concrete Compressive Strength (28 Days) 35 MPa

Steel Yield Strength 420 MPa

Strength Reduction Factor (ties) 0.85 -

Load 790 kN



Literature Review

Experimental Setup





Literature Review

Experimental Setup


Normal Design Under Design




Literature Review

Experimental Setup


Normal Design Under Design




Literature Review

Experimental Setup


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



Literature Review

Experimental Setup


Experimental Setup Concrete Mix Design



Literature Review

Experimental Setup


Experimental Setup Strain Gauge Fixing



Literature Review

Experimental Setup


Experimental Setup Epoxy Preparation-Primer



Literature Review

Experimental Setup


• 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



Literature Review

Experimental Setup


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 Co to +75 Co

Surface Drying Time ASTM D2939 6-8 hours

Bond Strength ASTM D4541 Concrete Failure

Experimental Setup Epoxy Preparation-Saturant



Literature Review

Experimental Setup


• 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



Literature Review

Experimental Setup


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 Co to +75 Co

Bond Strength ASTM D4541 > 2 N/mm2

Compressive Strength BS 6319-2 70 N/mm2 at 7 days

Experimental Setup Column Preparation



Literature Review

Experimental Setup


After

125 mm

125 mm

750 mm500 mm

Before

R = 25 mm

Experimental Setup Proposed Matrix



Literature Review

Experimental Setup


NC11

N2 N3 U1 U2 U3

NC21 NC22 NC23 UC21 UC22 UC23

N1

NC12 NC13 UC11 UC12

UF13NG11 NG12 NG13 UG11 UG12

UC13

UF23NG21 NG22 NG23 UG21 UG22

N: Standard U: Under

C: CFRP G: GFRP

First Number: # of Wraps Second Number : Sample Number



Literature Review

Experimental Setup


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



Literature Review

Experimental Setup


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



Literature Review

Experimental Setup


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



Literature Review

Experimental Setup


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



Literature Review

Experimental Setup


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



Literature Review

Experimental Setup


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



Literature Review

Experimental Setup


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



Literature Review

Experimental Setup


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



Literature Review

Experimental Setup


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



Literature Review

Experimental Setup


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



Literature Review

Experimental Setup


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



Literature Review

Experimental Setup


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 1.235N2 804 3.975 3.391 1.172 U2 546 4.329 3.407 1.271N3 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 1.173NC11 917 6.266 4.765 1.315 UC11 871 4.163 3.702 1.125NC12 1002 4.886 4.143 1.179 UC12 912 8.995 6.745 1.334NC13 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 1.209NC21 1014 5.701 4.212 1.353 UC21 1035 7.655 6.706 1.142NC22 1010 4.952 4.076 1.215 UC22 1053 6.629 5.131 1.292NC23 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 1.211NG11 977 5.639 4.438 1.271 UG11 845 5.529 4.890 1.131NG12 926 8.147 5.765 1.413 UG12 892 6.523 5.023 1.299NG13 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 1.245NG21 1044 7.178 3.543 2.026 UG21 938 5.601 4.446 1.260NG22 1141 7.489 3.139 2.386 UG22 940 9.401 7.598 1.237NG23 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



Literature Review

Experimental Setup


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%



Literature Review

Experimental Setup


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%


- 38.452% 5.595% 42.857% -13.393%



Literature Review

Experimental Setup


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%


- 626.88% 454.38% 650.00% 354.69%



Literature Review

Experimental Setup


Discussion of Results Mode of Failure

Column Type of Failure Position ColumnType of Failure

Position

NC11 Delamination Top UC11 Delamination Top + MiddleNC12 Delamination Top UC12 Delamination Top + MiddleNC13 Delamination Top UC13 Delamination Top + MiddleNC21 Delamination Top UC21 Delamination TopNC22 Delamination Top UC22 Delamination TopNC23 Debonding Top UC23 Delamination TopNG11 Debonding Middle UG11 Debonding Top + MiddleNG12 Debonding Top UG12 Debonding MiddleNG13 Debonding Middle UG13 Delamination TopNG21 Debonding Top UG21 Delamination TopNG22 Debonding Middle UG22 Debonding Top + MiddleNG23 Debonding Top UG23 Debonding Top



Literature Review

Experimental Setup


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.



Literature Review

Experimental Setup


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 …

Documents

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