Asphalt
Asphalt (or asphalt cement) is a sticky, black and highly viscous liquid or semi-solid that is derived from petroleum refining or processed directly from
bitumen-bearing rock (rock asphalt) or surface deposits (lake asphalt). Outside North America, the product is called bitumen.
Asphalt is a hydrocarbon with varying and complex constituents. They can be low to high molecular weight
polymers and condensation products consisting of chains or ring
structures. The chemical composition is approximately 80-85% C, 9-10%
H, 2-8% O, 0.5-0.7% S, small amounts of N and other trace metals. Asphalt has the mechanical characteristics of a thermoplastic polymeric material.
The primary use of asphalt is in asphaltic concrete used in road construction. Asphaltic concrete is a good example of a large particulate reinforced composite material. Asphalt is used as the glue or binder for ceramic aggregate particles. (Don't be confused by the terms, "Asphaltic concrete" is sometimes referred to as AC or simply "asphalt". However, strictly speaking, "asphalt" is just the binder.)
The Asphalt Institute in the U.S. has designated eight paving mixures.
