10. Composites

Question 1

What is a composite material?

Answer 1

• a material comprised of two or more different materials
• results in a material with enhanced properties

Question 2

What are the two more commonly used composites?

Answer 2

• carbon fibre reinforced polymer (CFRP)
• glass fibre reinforced polymer (GRP)

Question 3

What are composites?
(examples)

Answer 3

• CFRP
• GRP
• tungsten carbide
• aluminium composite board
• concrete
• reinforced concrete
• fibre cement
• engineered wood

Question 4

What are the properties of CFRP?

Answer 4

• carbon fibres mixed with polyester resin
• lightweight
• corrosion resistant
• tough
• hard
• good compressive strength
• low thermal expansion

Question 5

What are the uses of CFRP?

Answer 5

• sports equipment such as bicycle frames and tennis racquets
• fishing rods
• racing car bodies and parts
• helmets
• prosthetics

Question 6

What are the properties of GRP?

Answer 6

• glass fibres mixed with polyester resin
• lightweight
• corrosion resistant
• tough
• hard
• low thermal expansion
• good compressive strength

Question 7

What are the uses of GRP?

Answer 7

• boat hulls
• pond liners
• kayak shells
• sports car bodies and parts
• locomotive train cabs

Question 8

What are the properties of tungsten carbide?

Answer 8

• a cermet (mix of ceramic and metal particles)
• ceramic tungsten and cobalt metal
• hard
• tough
• resistant to high temperatures
• corrosion resistant

Question 9

What are the uses of tungsten carbide?

Answer 9

• cutting tools such as drill bits, lathe tool tips, router bits, kitchen knives

Question 10

What are the properties of aluminium composite board?

Answer 10

• aluminium sheets with a polyethylene core
• lightweight
• rigid
• tough
• malleable
• good thermal and sound insulation
• good vibration damping

Question 11

What are the uses of aluminium composite board?

Answer 11

• soundproofing panels in cars, buildings and boats
• signage

Question 12

What are the properties of concrete?

Answer 12

• cement powder, sand, aggregate particles mixed with water
• high compression strength
• low tensile strength
• few surface defects
• easy to mould

Question 13

What are the uses of concrete?

Answer 13

• pathways
• beams
• blocks
• driveways
• house foundation

Question 14

What are the properties of reinforced concrete?

Answer 14

• cement powder, sand, aggregate particles and polymer or steel rods (rebar) mixed with water
• high compression and tensile strength
• consistency across the structure
• few surface defects
• fire resistant

Question 15

What are the uses of reinforced concrete?

Answer 15

• buildings
• bridge piles and bridge spans
• retaining walls
• grid floors

Question 16

What are the properties of fibre cement?

Answer 16

• cement powder, sand, aggregate particles and polymer or steel fibres mixed with water
• lighter in weight than reinforced concrete
• hard
• tough
• good at low temperatures and in freeze/thaw situations

Question 17

What are the uses of fibre cement?

Answer 17

• suspended floors
• complex geometric shapes
• pathways

Question 18

What are the properties of engineered wood?
(plus example)

Answer 18

• e.g. glulam (glued laminated timber)
• timber laminates and MF adhesive
• good aesthetics
• natural alternative to reinforced concrete
• more lightweight than concrete alternatives
• fire resistant
• good structural stability
• corrosion proof

Question 19

What are the uses of engineered wood?

Answer 19

• beams
• bridges
• domes
• arches
• decking
• roof beams
• rafters