Asphalt is a sticky, black and highly viscous liquid or semi-solid that is present in most crude petroleums and in some natural deposits sometimes termed asphaltum.
The uses of asphalt
- The primary use of asphalt is in road construction, where it is used as the glue or binder for the aggregate particles.
- The largest use of asphalt is for making asphalt concrete for road surfaces. Asphalt concrete is a composite material commonly used in construction projects such as road surfaces, airports and parking lots. It consists of asphalt (used as a binder) and mineral aggregate mixed together, then laid down in layers and compacted. Asphalt pavement material is commonly composed of 5 percent asphalt cement (concrete) and 95 percent aggregates (stone, sand, and gravel). Due to its highly viscous nature, asphalt cement must be heated so that it can be mixed with the aggregates at the asphalt mixing plant.
- Asphalt road surface is the most widely recycled material. According to a report issued by the Federal Highway Administration and the United States Environmental Protection Agency, 80% of the asphalt removed each year from road surfaces during widening and resurfacing projects is reused as part of new roads, roadbeds, shoulders and embankments.
- Asphalt is widely used in airports around the world. Due to the sturdiness, it is widely used for runways dedicated to aircraft landing and taking off.
