2. SEEM501
CARBON FIBER VS STEEL REINORCEMEN
By Mohamed Nabil, student in MSc in structural engineering
British University in Dubai
Module Tutor: Professor Abid Abu Tair, professor of Structural Engineering BUID
CARBON FIBER VS STEEL REINFORCEMENT 2
3. Presentation outline
• What is Carbon Fiber ?
• History of Carbon Fiber.
• Carbon Fiber production technique.
• Carbon Fiber properties.
• Repairing structures by using Carbon Fiber.
• Advantages of using Carbon Fiber in repairing structures.
• Disadvantages of using Carbon Fiber in repairing structures.
CARBON FIBER VS STEEL REINFORCEMENT 3
4. Carbon Fiber is defined as a fiber containing at least 92% carbon from its weight, while
the fiber containing at least 99% carbon from its weight is usually called a graphite
fiber. Carbon Fiber consist a fibers its diameter about 5 –10 μm and composed mostly of
carbon atoms.
CARBON FIBER VS STEEL REINFORCEMENT 4
What is Carbon Fiber?
5. • In late 1879, Thomas Edison was the first to use carbon fibers as
filaments for early light bulbs.
• In late 1950's that high tensile strength carbon fibers were
discovered. Rayon became the first precursors used to create
these modern fibers. Ultimately, it was replaced by more
effective materials such as polyacrylonitrile (PAN) and
pitch.
CARBON FIBER VS STEEL REINFORCEMENT 5
History of Carbon Fiber
6. CARBON FIBER VS STEEL REINFORCEMENT 6
Carbon Fiber production technique
A. Based on pitch (coal tar and petroleum products)
B. Based on Polyacrylonitrile (PAN)
7. CARBON FIBER VS STEEL REINFORCEMENT 7
Carbon Fiber production technique
8. CARBON FIBER VS STEEL REINFORCEMENT 8
Carbon Fiber properties
• HIGH STRENGTH TO WEIGHT RATIO
The relation between the material strength and its density is an indication for how come this
material can provide a specific strength with specific density.
NO MATERIAL
COMPRESSIVE STRENGTH TO WEIGHT
RATIO ((KN/m2)/kg)
1 Spectra fiber 3619
2 Kevlar 2514
3 Carbon Fiber 2457
4 Glass Fiber 1307
5 Steel alloy 254
6 Aluminum alloy 222
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Carbon Fiber properties
• RIGID MATERIAL
To measure the rigidity for any material, it can be from measuring the material young's
modulus. Young's modulus is the relation between stress and strain for any material.
NO MATERIAL YOUNG'S MODULUS - GPa
1 Carbon fiber reinforced plastic 181
2 Steel alloy 200
10. CARBON FIBER VS STEEL REINFORCEMENT 10
Carbon Fiber properties
• CORROSION AND CHEMICAL RESISTANCE MATERIAL
The carbon fiber as composite material has very good resistance to corrosion and chemical
effects. For example in the repairing of cracked beam, the repairing can done by apply the
carbon fiber to the defects areas with glue without any concrete cover unlike steel
reinforcement.
11. CARBON FIBER VS STEEL REINFORCEMENT 11
Carbon Fiber properties
• HIGH TENSILE STRENGTH
The ultimate stress of the carbon fiber is always equal to 5 to 10 time the yielding stress in the steel.
Material yield
strength -
MPa
Ultimate strength
- MPa
Steel, structural
ASTM A36 steel
250 400-550
Aluminum
alloy[15] 2014-T6
414 483
Carbon fiber N/A 1600 for laminates,
4137 for fibers
alone
Copper 99.9% Cu 70 220
12. CARBON FIBER VS STEEL REINFORCEMENT 12
Carbon Fiber properties
• ABILITY TO PRODUCE COMPLEX SHAPES AND DIFFERENT SIZES
One of the advantages of carbon fiber and composites is that virtually any shape or size can be
fabricated. All that is required is a tool, or mold, that is used to form the layers of carbon fiber.
13. CARBON FIBER VS STEEL REINFORCEMENT 13
Repairing structures by using Carbon Fiber
• The carbon fiber reinforced polymers can used in different aspect in civil industries, such as
but not limited to infrastructure pipeline, bridges and buildings.
• The carbon fiber materials can used in different stages, such as construction stage as a part
of reinforced concrete used to resist the tensile forces and stress. Also can used in post
construction stage in the repairing and strengthening operation of structural elements.
14. CARBON FIBER VS STEEL REINFORCEMENT 14
Repairing structures by using Carbon Fiber
• The following list shows the types of
CFRP shapes and place of use in the
structures:
• Plates and strips, used to strengthen the
horizontal structure elements such as slabs and
bridges decks to resist bending stress and
repair the cracks in the structural elements.
• Wrapped sheets, to enhance the shear stress in
beams. And strengthening the columns
15. CARBON FIBER VS STEEL REINFORCEMENT 15
Advantages of using Carbon Fiber in repairing structures
• Strength of CFRP
The ultimate strength of CFRP is likely
to be at least five times the ultimate
strength of steel for the same cross-
sectional area.
0
200
400
600
800
1000
1200
1400
1600
1800
Steel Glass Fiber Carbon Fiber
Strength N/mm2
16. CARBON FIBER VS STEEL REINFORCEMENT 16
Advantages of using Carbon Fiber in repairing structures
• Low weight of CFRP & Reduce
construction period
17. CARBON FIBER VS STEEL REINFORCEMENT 17
Advantages of using Carbon Fiber in repairing structures
• Durability
CFRP plates do not suffer from such deterioration
because it is a chemical composite material has good
resistance to corrosion and chemical effects.
Steel reinforcement which used in the repairing of
concrete structures most of time suffer from
corrosion, because it will be installed without
concrete cover.
18. CARBON FIBER VS STEEL REINFORCEMENT 18
Advantages of using Carbon Fiber in repairing structures
19. CARBON FIBER VS STEEL REINFORCEMENT 19
Advantages of using Carbon Fiber in repairing structures
• Maintenance of strengthening
system
Steel plates will required maintenance in the long
term after the installation in the repaired structures
like waterproofing and firefighting repainting.
CFRP composite plates will not require such
maintenance.
20. CARBON FIBER VS STEEL REINFORCEMENT 20
Advantages of using Carbon Fiber in repairing structures
• Sustainable and green material
The using of CFRP in building industries increase the
structure life time. This may lead to decrease the
demand of the building materials like cement and steel.
As known, the cement production has a big effect on the
ecological footprint because it is produce huge amount of
carbon dioxide.
21. CARBON FIBER VS STEEL REINFORCEMENT 21
Disadvantages of using Carbon Fiber in repairing structures
High initial cost of CFRP production
CFRP composite plates are more expensive than steel plates
of the equivalent load capacity.
