What is a composite?

A composite is a mixture of materials. Each material has different properties. The composite has properties that are a combination of the properties of the materials it is made up of. Scientists experiment with different mixtures. They develop composites with the best properties for particular uses. Reinforced concrete is an example of a composite material. Reinforced concrete consists of steel bars with concrete around it. Concrete is not damage when forces press on it. But it breaks easily when stretched. Steel is not damaged by stretching forces. Together, steel and concrete put up with strong squashing and stretching forces.

 

Other composites

Carbon-fibre reinforced plastic

A bicycle frame is made from carbon-fibre reinforced plastic (CFRP). The composite consists of two materials:

• Carbon fibres, which are thin tubes of carbon. The fibres are woven into a fabric.

• A gluelike polymer, which is moulded into different shapes when soft.

 

Some cyclists prefer CFRP bicycles to steel one.

• CFRP has a lower density, making bicycles lighter

• CFRP does not rust

• CFRP is very strong

• you can mold CFPR into any shape

CFPR has some disadvantages. Bicycles made from CFPR are expensive. If crashed, they are badly damaged.

An aeroplane; Airbus A380 contains 20% composite materials. One of these composites is glass-fibre-reinforced aluminium. The materials in this composite include:

• Thin layer of aluminium

• Layers of glass fibre

• A gluelike polymer to join the layers