Cement is made by heating powdered limestone with clay.

Cement is an ingredient in mortar and concrete. Mortar - used to join bricks together - is made by mixing cement with sand and water. Concrete is made by mixing cement with sand, water and aggregate (crushed rock).

Advantages and disadvantages of various building materials

Concrete is easily formed into different shapes before it sets hard. It is strong when squashed, but weak when bent or stretched. However, concrete can be made much stronger by reinforcing it with steel.

Limestone, cement and mortar slowly react with carbon dioxide dissolved in rainwater and wear away. This damages walls made from limestone, and leaves gaps between bricks in buildings. These gaps must be filled in or ‘pointed’.

Pollution from burning fossil fuels makes the rain more acidic than it should be, and this acid rain makes these problems worse.

	Created by Landon Valencia about 9 years ago

	Copied by ed.wilson89 about 9 years ago

GCSE Chemistry: The Crust