carbon fiber vs steel reinforcement

SEEM501

CARBON FIBER VS STEEL REINFORCEMEN

Mohamed Nabil – 2013260072 1 November 2014

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

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 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.


What is Carbon Fiber?

• 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.


History of Carbon Fiber


Carbon Fiber production technique

A. Based on pitch (coal tar and petroleum products)

B. Based on Polyacrylonitrile (PAN)

http://www.steelfibercn.com/wp-content/uploads/2012/07/Polyacrylonitrile-fibers.jpg

http://www.steelfibercn.com/wp-content/uploads/2012/07/Polyacrylonitrile-fibers.jpg


Carbon Fiber production technique


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



• 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



• 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.



• 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



• 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.


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.


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


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



• Low weight of CFRP & Reduce

construction period



• 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.



• 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.



• 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.


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.


THANK YOU

ANY ?