Aggregate
Hard, inert mineral material, such as gravel, crushed rock, sand, or crushed stone, used in pavement applications either by itself or for mixing with asphalt.

Aspalt Cement
A derivative of crude oil refining that is the binder or "glue" in the asphalt pavement mixture.

Asphalt Pavement (Hot Mix Asphalt)
A high-quality, thoroughly controlled, engineered mixture made by heating asphalt cement and mixing it with aggregates and mineral fillers. Typical proportions are 94 to 96 percent aggregate and 4 to 6 percent asphalt cement.

Asphalt Plant or Asphalt Facility
A manufacturing facility that produces asphalt paving mixtures.

Asphalt Rubber Binder (AR)
Recycled ground tire rubber is added to conventional asphalt cement. Factory-reject roofing shingles may also be added to the asphalt cement.

Binder
The "glue" that holds a pavement together. In asphalt pavements, it is asphalt cement. It may be modified with polymers to improve its properties.

Crumb Rubber
Asphalt rubber binder with a consistency ranging from coffee grounds to peanut butter.

Hot Mix Asphalt (Asphalt Pavement)
A high-quality, thoroughly controlled, engineered mixture that is made by heating asphalt cement and mixing it with aggregates and mineral fillers. Typical proportions are 94 to 96 percent aggregate and 4 to 6 percent asphalt cement.

Hot Mix Asphalt Overlay
One or more courses (layers) of HMA over an existing pavement.

Maintenance Mix
A mixture of asphalt emulsion and mineral aggregate used in relatively small areas to patch holes, depressions, and distressed areas in existing pavements.

Mineral Fillers
Sand and fine particles of mineral material that exhibit specific characteristics that are helpful in the design and construction of asphalt pavements.

Pavement Base
The lower or underlying pavement course atop the subbase or subgrade (natural earth) and under the top or wearing course.

Reclaimed Asphalt Pavement
Asphalt paving material that has been removed from a road or highway and crushed for reuse or recycling into new pavements.

Recycled Asphalt Mix
A mixture produced by processing reclaimed asphalt pavement into new pavement. Materials such as roofing shingles, glass, foundry sand, and slag can also be incorporated into asphalt pavements.