Asphalt Glossary
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.
Asphalt Cement:
A derivative of crude oil refining that is the binder or "glue" in the asphalt
pavement mixture.
Asphalt Cement Storage: Asphalt cement is stored in tanks that meet stringent regulatory guidelines for spill prevention.
Asphalt Pavement (Hot Mix Asphalt): A high-quality, thoroughly controlled, engineered mixture made be 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.
Batch Plants: An asphalt plant that produces asphalt in batches as needed to go straight to work sites.
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.
Cold Feed Bins: Accurately meter the different aggregates used in the mix to the drying drum. Aggregates are usually stored in stockpiles or they may be stored in large silos or bunkers.
Crumb Rubber: Asphalt rubber binder with a consistency ranging from coffee grounds to peanut butter.
Drum Plants: An asphalt plant that produces asphalt continuously and can store the asphalt for several days in heated storage silos.
Dryer Drum: Dries and heats aggregates by tumbling them through hot air. In a parallel-flow drum, aggregates move in the same direction as the hot air. In a counter-flow drum, aggregates move in the opposite direction.
Emission Control System:
Sometimes called a baghouse, this system traps and removes fine sand and dust particles
and returns them to the mix.
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 sub base or sub grade (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.
Storage Silos: Drum mix plants must have silos since they produce asphalt continuously. Batch plants do not require a silo, but often have them to increase plant production. Storage silos are insulated and may be heated to prevent heat loss. A mix may be stored in a silo for days.
Asphalt Cement:
A derivative of crude oil refining that is the binder or "glue" in the asphalt
pavement mixture.
Asphalt Cement Storage: Asphalt cement is stored in tanks that meet stringent regulatory guidelines for spill prevention.
Asphalt Pavement (Hot Mix Asphalt): A high-quality, thoroughly controlled, engineered mixture made be 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.
Batch Plants: An asphalt plant that produces asphalt in batches as needed to go straight to work sites.
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.
Cold Feed Bins: Accurately meter the different aggregates used in the mix to the drying drum. Aggregates are usually stored in stockpiles or they may be stored in large silos or bunkers.
Crumb Rubber: Asphalt rubber binder with a consistency ranging from coffee grounds to peanut butter.
Drum Plants: An asphalt plant that produces asphalt continuously and can store the asphalt for several days in heated storage silos.
Dryer Drum: Dries and heats aggregates by tumbling them through hot air. In a parallel-flow drum, aggregates move in the same direction as the hot air. In a counter-flow drum, aggregates move in the opposite direction.
Emission Control System:
Sometimes called a baghouse, this system traps and removes fine sand and dust particles
and returns them to the mix.
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 sub base or sub grade (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.
Storage Silos: Drum mix plants must have silos since they produce asphalt continuously. Batch plants do not require a silo, but often have them to increase plant production. Storage silos are insulated and may be heated to prevent heat loss. A mix may be stored in a silo for days.