Asphalt is a black tar-like substance primarily used for road construction. It is manufactured by mixing asphalt cement with aggregates such as stone, sand, or gravel. Asphalt cement is a product of oil refining, used as a binder to glue aggregates together, thereby producing asphalt.
As one of the world’s oldest building materials, its history as a roadbuilding material dates back to 625 B.C. It currently covers more than 94 percent of United States roads. It is also used for driveways, parking lots, airport runways, racetracks, tennis courts, and a variety of other applications requiring a smooth, durable driving surface.
The word asphalt derives from the Greek word asphaltos, meaning “secure.” However, outside of North America, asphalt is commonly referred to as bitumen. This material is also sometimes called Hot Mix Asphalt, blacktop, tarmac, macadam, plant mix, asphalt concrete, or bituminous concrete.
Hot Mix Asphalt is the result of heating asphalt in a central mixing plant. After the asphalt is heated, it is transported to the site of the project, spread over a surface and compacted before it cools.