Compound

A compound might be described as a material made from two or more materials with specific ratios, bonded at a molecular or microscopic level.

More specifically a chemical compound is any substance composed of identical molecules consisting of atoms of two or more chemical elements from the periodic table. For example, water is a compound because it is made up of water molecules - made of hydrogen and oxygen atoms in the defined proportion of two hydrogens for one oxygen.

In terms of general materials compounds, to some extent (incorrectly) the term might be used interchangeably with composite, though this normally refers to different materials being combined at a macroscopic rather than molecular level. For example cement is a compound material, made from limestone and clay heated to extremely high temperatures of up to 1600°C. Cement in turn is a constituent part of concrete which might also be referred to as a compound material or more commonly a mix made up of (portland) cement, aggregate (gravel, crushed stones), sand and water. PVC polyester is a composite - consisting of a PVC substrate coated with polyester.

[edit] Related articles on Designing Buildings

• Aggregate.
• Biocement
• Composites.
• Concrete.
• Element.
• Fibre cement.
• Portland cement.
• Types of cement.
• Types of materials.