1. FRP external strengthening Flexural upgrade
CIVI 6061 – SHM, Fall 2014
Now Presenting :
FRP external strengthening Flexural upgrade
Adel Farghadan
Yahya fakori
November 19th,2014

2. CIVI 6061-Strengthening of bridges using FRP
11/15/2014
CIVI 6061-Strengthening of bridges using FRP
Project Objective:
Introduction to FRP and literature review
Flexural enhancement of externally bonded FRP (EBF) (sheets or Strip)
Developing a spreadsheet to investigate EI and Afrp/As on Moment capacity of a beam
Reviewing of 2 case studies
What is Fiber reinforced polymer (FRP) ?
A composite material (two phased) , Anisotropic properties
Characterized by High tensile strength and linear elastic behavior
Interface
Protector part
Reinforcement part
FRP
Main component EBF
Courtesy of Gopal Rai
Courtesy of ISIS Educational Module
•Affordable materials
•Light weight and accordingly high strength-to-weight ratio
•Ease of handling and application resulting in eliminating heavy lifting machineries and equipments
•Anti corrosion
Reinforcement part Fiber (carbon, glass, aramid), D=n x10 µm
Protector part (Matrix) epoxies
Interface Paste (bonding agent)

3. CIVI 6061-Strengthening of bridges using FRP
11/15/2014
CIVI 6061-Strengthening of bridges using FRP
FRP inherits its Mech. Porp from constituents
C. Tuakta (2005)
FRP
Mech. Prop.
Fiber architecture
Vf /Vm , similar to C/W ratio in Concrete
Fiber off-axis angel
rule of mixtures
Vf /Vm , similar to C/W ration in concrete
Fiber architecture
Fiber off-axis angel
Courtesy of ISIS Educational Module
I.e. module of elasticity rule of mixture (ROM) for unidirectional FRP
Canada
CSA-S6-06 (2006) Fibre Reinforced Structures, “Canadian Highway Bridge Design Code” Canadian Standards Association, pg
CSA-S (R2007) “Design and Construction of Building Components with Fibre-Reinforced Polymers” Canadian Standards Association
0 degree largest strength, stiffness and least deflection
45 degree shows ductility and deflection 40% more than 0 degree orientation
90 degree fiber exhibited the most ductile behavior.
Fiber off-axis effect
Norris and Saadatmanesh (1994)

4. CIVI 6061-Strengthening of bridges using FRP
11/15/2014
CIVI 6061-Strengthening of bridges using FRP
Why strengthening by EBF (externally bonded FRP)?
High performance construction material
Literature reviews show that EBF enhances ultimate flexural capacity ranged from to 97 percent [P. A. Ritchie (1988) ]
Affordable strong materials
4-5 x steel
High strength-to-weight ratio
Ease in handling and application
Anti corrosion
Low maintenance cost
How it works?
Externally bonded to tensile face of beam
Concrete face
Interface
Matrix
Fiber
•Affordable materials
•Light weight and accordingly high strength-to-weight ratio
•Ease of handling and application resulting in eliminating heavy lifting machineries and equipments
•Anti corrosion
FRP Strip
EBF Beam
FRP
Load transfer in FRP system
Installation Methods
Pre-cured (factory-produced) (Strip/Plate)
Wet-lay up ,at site installation, matrix acts as a bond (flexible sheet)
Rob Irwin (1) and Amar Rahman (2)

5. CIVI 6061-Strengthening of bridges using FRP
11/15/2014
CIVI 6061-Strengthening of bridges using FRP
Flexural Design of rectangular EBF
Assumption
εC>εCu & εs >εy
εfrpu>εfrp
Determine C by equilibrium
of forces
Calculate εfrp
Check εfrpu>εfrp
If not ok go to 5
calculate Mr
And check εs >εy
Finish
New assumption
εfrpu=εfrp & εC<εCu
Determine C by
εfrpu
& verify εC<εCu
Calculate Mr 1
BEAM
FRP h b c d
rule of mixtures 2 7
Design process
flow chart 3
steel 6
A spreadsheet was developed based on design process flow chart 4 5
Design code
CSA-S6-06 (2006) Fiber Reinforced Structures, “Canadian Highway Bridge Design Code” Canadian Standards Association, pg
CSA-S (R2007) “Design and Construction of Building Components with Fibre-Reinforced Polymers” Canadian Standards Association

6. CIVI 6061-Strengthening of bridges using FRP
11/15/2014
CIVI 6061-Strengthening of bridges using FRP
Sensitivity analysis of a rectangular EBF
For different value of f’c , Afrp/As increases until
rule of mixtures
FRP material
Steel
Concrete
Efrp = 155 Gpa
Es = 200 GPa
Ec=25Gpa
Afrp = x A s
fy = 400 MPa
f’c =25-45Mpa
εfrpu = 1.55%
As = 300 mm²
εC=0.35%
Carbon FRP
εy=0.20%
Canada
CSA-S6-06 (2006) Fibre Reinforced Structures, “Canadian Highway Bridge Design Code” Canadian Standards Association, pg
CSA-S (R2007) “Design and Construction of Building Components with Fibre-Reinforced Polymers” Canadian Standards Association
Cross section of EBF
Ductile range
Ductile range
Area Transform method
Concrete strength, f’c = 45 Mpa
• As = 300 mm²
• Steel yield strength, fy = 400 MPa
• Steel elastic modulus, Es = 200 GPa
• Carbon FRP: Afrp = 60 mm²; εfrpu = 1.55%;
Efrp = 155 GPa
• Neglect initial strains in the concrete and steel
• CSA A23.3 requirements

7. CIVI 6061-Strengthening of bridges using FRP
11/15/2014
CIVI 6061-Strengthening of bridges using FRP
What was learned?
EBF enhances the flexural capacity of beam ranged from 47 to 97 percent.
The Afrp/As = 0.5 is the optimum ratio because remarkable change in enhancement has already happened (near 75% for f’c = 45 mpa).
The higher f’c , the more enhancement is expected.
The change in flexural rigidity (EI) has dramatic effects on moment resisting capacity of the component .
With the help of discussed chart , for a desired flexural enhancement , the Afrp/As can be obtained. i.e. for 40 percent of enhancement the area ratio of FRP to area of steel is equal to 0.25.

8. CIVI 6061-Strengthening of bridges using FRP
11/15/2014
CIVI 6061-Strengthening of bridges using FRP
rule of mixtures
Thank you
Canada
CSA-S6-06 (2006) Fibre Reinforced Structures, “Canadian Highway Bridge Design Code” Canadian Standards Association, pg
CSA-S (R2007) “Design and Construction of Building Components with Fibre-Reinforced Polymers” Canadian Standards Association
Concrete strength, f’c = 45 Mpa
• As = 300 mm²
• Steel yield strength, fy = 400 MPa
• Steel elastic modulus, Es = 200 GPa
• Carbon FRP: Afrp = 60 mm²; εfrpu = 1.55%;
Efrp = 155 GPa
• Neglect initial strains in the concrete and steel
• CSA A23.3 requirements