Asphalt is made by combining coarse and medium grained aggregate material with a black, petroleum binding agent that holds the pavement together. The asphalt concrete mixture is then applied in different layers:

1. Base Layer – Consists of unbound and bituminous-bound materials laid over the sub base, which provides a stable surface to support new pavement.
2. Binder and Surface Layer – Consists of large aggregate mixed with oil to increase the strength and durability of the pavement structure.
3. Top Layer – Consists of a fine layer of small aggregate asphalt to provide a smooth ride and complete the jet-black aesthetic of the pavement surface.

Types of Asphalt

There are five types of asphalt categorized by the type of aggregate, which also determines the structure and strength of the pavement surface.

1. Hot Asphalt – A permanent paving and patching solution that is manufactured and applied at temperatures between 270° F and 325° F to maintain pliability before the asphalt cools and becomes unworkable.
2. MC Cold Mix/Colt Patch – A temporary application of asphalt laid at colder temperatures to slow the curing process, and best applied in low-traffic areas.
3. Warm Mix Asphalt – A permanent paving and patching solution that is manufactured and applied at temperatures between between 30° F and 120° F, enabling a longer paving season, and a longer distance between the materials plant and the job site.
4. Porous Mix Asphalt – Often used in parking lots, driveways, playgrounds, and sidewalks, porous mix asphalt solutions allow water to drain through its surface, into the underlying stone recharge bed, where it slowly infiltrates into the soil. Porous mix asphalt solutions offer greater functionality to improve safety, manage stormwater, and eliminate the need to deal with water puddles.
5. Dense Grade Asphalt – Used for general purposes and suitable for all pavement layers, dense-grade asphalt is a well-graded hot asphalt mix that provides prolonged durability against punishing weather and traffic conditions.