Glossary of Terms for Paving and Asphalt Repair


A mineral material, such as gravel, crushed rock, slag, or crushed stone, used in pavement applications or for mixing with asphalt and sealcoating products.


A general term used to describe roads and parking lots constructed and made with asphalt bitumen. Also known as asphalt concrete.

Asphalt Binder:

Asphalt cement that is classified according to the Standard Specification for Performance Graded Asphalt Binder, AASHTO Designation MP1. It can be either unmodified or modified asphalt cement, as long as it complies with the specifications.

Also known as SS-1H asphalt binders are an anionic emulsion designed for use as a tack coat for patching, paving, overlays and coating asphalt. SS-1H promotes adhesion to asphalt. It can be applied via sprayer, brush or squeegee and dilution is not necessary.

Asphalt Concrete:

A mixture of asphalt binder and aggregate thoroughly mixed and compacted.

Alligator Cracks:

Interconnected cracks forming a series of small blocks resembling an alligator’s skin, and caused by excessive deflection of the surface over unstable subgrade.

Asphalt Distributor:

A truck or a trailer having an insulated tank, heating system and distribution system. The distributor applies asphalt to a surface at a uniform rate.

Asphalt Emulsion:

An emulsion of asphalt binder and water that contains a small amount of an emulsifying agent.

Asphalt Emulsion Mix (Cold):

A mixture of unheated aggregate and emulsified asphalt binder. It can be plant-mixed or mixed in-place.

Asphalt Emulsion Mix (Warm):

A mixture of asphalt emulsion and aggregate usually prepared in a conventional hot mix asphalt plant at a temperature less than 200°F. It is distributed and compacted at a temperature above 150°F.

Asphalt Leveling Course:

A course of hot mix asphalt of variable thickness used to eliminate irregularities in the contour of an existing surface prior to placing the subsequent course.

Asphalt Pavements:

Pavements consisting of a surface course of asphalt concrete over supporting courses.

Asphalt Sealing Additives:

Additives added to sealer mixes to enhance the qualities of asphalt. Some additives reduce power steering marks, while others enhance a sealcoating product’s resistance to oil, fuels and grease. You can also find additives to increase resistance to water.

Asphalt Tack Coat:

A thin application of asphalt binder applied to an existing asphalt concrete. Asphalt emulsion diluted with water is the preferred type. It is used to form a bond between an existing surface and the overlying course.


Generic term for material installed prior to asphalt paving. Lack of adequate base material is a primary cause of pavement failures. Base material is the layer in the pavement system below the binder and surface courses.

Batch Plant:

A manufacturing facility for producing asphalt paving mixtures that proportions blending. They manufacture asphalt in batches rather than continuously and are more suited for small manufacturing runs and (frequent) changes in mixture types.

Black Top:

Common "slang" term for asphalt. This term should not be used in requesting any specifications or work.


The hot mix asphalt course immediately below the surface course, generally consisting of larger aggregates and less asphalt than the surface.


is a sticky, black, and highly viscous liquid or semi-solid form of petroleum. It may be found in natural deposits or may be a refined product, and is classed as a pitch. Before the 20th century, the term asphaltum was also used.


The Certified Access Specialist (CASp) program was created by Senate Bill 262 (Chapter 872, 2003) and is designed to meet the public's need for experienced, trained, and tested individuals who can inspect buildings and sites for compliance with applicable state and federal construction-related accessibility standards. The CASp program is governed by Title 21 Voluntary Certified Access Specialist Program Regulations.

The CASp program was developed as a proactive measure to protect property and business owners from unnecessary disabled access-related lawsuits that do not advance the intent of the ADA.

The CASp program applies to properties that have been surveyed by a CASp inspector after January 1, 2009. If a property or business has a CASp survey, it affords the property or business owner enhanced legal benefits if a construction-related accessibility claim is made against that property.

The legal benefits include a court granted 90-day stay of the proceedings with respect to the claim and a scheduled early evaluation conference. A stay is a temporary halting of all litigation which precludes attorneys from engaging in motions or discovery that may inflate attorneys’ fees and final settlements.The early evaluation conference is a court run mediation between the parties to facilitate negotiations and to expedite settlement.

CASp Report:

Typically when a certified access specialist is hired they will do a survey of your property and then provide you with a report. Depending on the CASp inspector that is hired, this report may contain some or all of the following information.

Identification of the location of each access feature at the facility. Color photographs of each access element. Color coded data sheets showing all existing measurements of each element. Non-compliant items area coded in red. Notes on any additional compliance issues. Site specific possible solutions for removal of barriers. General design details for compliant alterations. Empire recommends Compliance Design Consultants because of the level of detail offered in there reports. However a complete list is available here at the Division of State Architects website.

Channels (Ruts):

Channeled depressions that sometimes develop in the wheel paths on pavement.

Coarse Aggregate:

Coarse aggregate refers to broken pieces of rock used in the construction industry. They are typically available in sizes of 10, 12, 16, 20, 25, 32 and 40mm.


Compaction reduces the volume of air in Hot Mix Asphalts. There are three basic pieces of equipment available for Hot Mix Asphalt compaction: (1) the paver screed, (2) the steel wheeled roller and (3) the pneumatic tire roller.


Vertical cleavage of the pavement caused by traffic loading, thermal stresses and/or aging of the binder.

Crack Filling:

Crack filling is the placement of asphalt emulsion into non-working cracks to reduce water infiltration and to reinforce the adjacent pavement. Often the best option for non-working cracks with moderate to no edge deterioration.

Crack Sealing:

Crack sealing is a method in which hot sealant is applied to working cracks to prevent water intrusion. Often best option for cracks with limited edge deterioration. Crack sealants are rubberized and have the ability to seal the crack while staying flexible with the pavement’s movement. Beneficial for active cracks that continue to extend in size and severity over time, crack sealants stop water and debris from entering the crack, protecting the longevity of the pavement.


The breaking up of a pavement into small, loose fragments caused by traffic or weathering.Often found on the edge of parking lots along curbs and gutters.


Any change of a pavement surface from its original shape.

Edge Joint Cracks:

The separation of the joint between the pavement and the shoulder, commonly caused by the alternate wetting and drying beneath the shoulder surface. Other causes are shoulder settlement, mix shrinkage, and trucks straddling the joint.

Effective Thickness:

The ratio of the thickness of an existing pavement material compared to the equivalent thickness of a new HMA layer.

Emulsifying Agent or Emulsifier:

The chemical added to the water and asphalt that keeps the asphalt in stable suspension in the water.

Fatigue Resistance:

The ability of asphalt pavement to resist cracking caused by repeated flexing.


A difference in elevation of two slabs at a joint or crack.

Fine Aggregate:

Generally consist of natural sand or crushed stone with most particles being able to pass through a 3/8-inch sieve.


The ability of an asphalt pavement structure to conform to settlement of the foundation. Generally, flexibility of the asphalt paving mixture is enhanced by high asphalt content.

Fog Seal:

A light application of diluted asphalt emulsion. It is used to renew old asphalt surfaces, seal small cracks and surface voids, and inhibit raveling.

Full-Depth Asphalt Pavement:

The term FULL-DEPTH (registered by the Asphalt Institute with the U.S. Patent Office) certifies that the pavement is one in which asphalt mixtures are employed for all courses above the subgrade or improved subgrade. A Full-Depth asphalt pavement is placed directly on the prepared subgrade.

Grade Depressions:

Localized low areas of limited size.


The degree to which a surface is angled. See “Slope” below.

Heavy Trucks:

Two-axle, six-tire trucks or larger. Trucks with heavy-duty, wide-base tires are included.

Hot Mix Asphalt (HMA):

Thoroughly controlled hot mixture of asphalt binder and well-graded, aggregate,which can be compacted into a uniform mass.

Hot Mix Asphalt(HMA) Overlay:

One or more layers of HMA over an existing pavement.


The resistance an asphalt pavement has to the passage of fluids into or through the pavement.

Lane Joint Cracks:

Longitudinal separations along the seam between two pavinglanes.


A layer of paving material applied to a base or a previous layer.

Lime Treated Subgrade:

A subgrade preparation technique in which the subgrade soil and added lime are mechanically mixed and compacted to produce a higher modulus base material than the on site material.

Lime-Fly Ash Base:

A road base material consisting of a blend of mineral aggregate, lime, fly ash, and water, which when combined and compacted produces a dense mass of increased strength.

Longitudinal Crack:

A vertical crack in the pavement that flows parallel to the centerline.

Maintenance Mix:

A mixture of asphalt emulsion and mineral aggregate for use in relatively small areas to patch areas in existing pavements.


A mixture of polymer modified asphalt emulsion, crushed dense graded aggregate, mineral filler, additives and water. It provides a thin resurfacing of 3/8 to 3/4 inch (10 to 20 mm) to the pavement.

Milling Machine:

A self-propelled unit equipped with carbide-tipped cutting head for the pulverization and removal of layers of asphalt from pavements.

Multiple Surface Treatment:

Two or more surface treatments placed one on the other. A multiple surface treatment is a denser wearing and waterproofing course than a single surface treatment.

Oil Spot Primers:

Products applied to oil and grease spots on parking lots to help prevent oil from bleeding through freshly applied sealcoat.


The placement of asphalt over an existing asphalt or cement concrete surface.

Pavement Base:

The lower or underlying pavement layer atop the subbase or subgrade.

Pavement Structure:

The entire pavement system from subgrade to the surface.

Petromat Overlay:

A crack retardant fabric membrane placed on the surface of existing pavement under a new overlay.

Plant Mix (Cold):

A mixture of emulsified asphalt and unheated aggregate prepared in a mixing plant and spread and compacted with paving equipment while the mixture is at or near ambient temperature.

Plant Mix Base:

Aggregate uniformly coated with asphalt cement or emulsified asphalt foundation produced in a mixing plant.

Pneumatic-Tire Roller:

A compactor with a number of tires spaced so their tracks overlap delivering a kneading type of compaction.

Portland Cement Concrete:

Aggregated cement with binder, characterized by gray/white color. Relatively smooth, uniform concrete surface having few exposed aggregates.


Disintegration resulting in bowl-shaped openings in the pavement.

Power Sweeper:

A power operated rotary broom used to clean loose material from the pavement surface.


Discharge of water and subgrade soils along joints, cracks and pavement edges.


The gradual roughening of the surface texture of asphalt pavement. The fine sandy particles are “washing” away leaving the pavement with course rock on the surface and a much rougher texture that originally constructed.

Reclaimed Asphalt Pavement (RAP):

Excavated asphalt pavement that has been pulverized to be used as an aggregate in the recycling of asphalt pavements.

Recycled Asphalt Mix:

A mixture produced after processing reclaimed asphalt pavement materials.

Reflection Cracks:

Cracks in asphalt overlays that reflect the crack pattern in the pavement structure below it.


The asphalt binder that remains from an asphalt emulsion after the emulsifying agent has broken and cured.


All facilities on which motor vehicles are intended to travel such as secondary roads, interstate highways, streets and parking lots.


Fine aggregate resulting from natural disintegration and abrasion or processing of rock.

Saw-Cut and Seal:

A method of controlling reflective cracking in overlays that involves constructing joints in the new overlay exactly over the joints in the existing pavement.


A service that is typically sold by paving contractors designed to increase the lifespan of your parking lot. Slurry Seal is made a mixture of water, asphalt emulsion, aggregate (very small crushed rock), and other additives. Sealcoat is applied by either squeegee, brush, or sprayer to the surface of your asphalt. Sealcoating products protect and beautify asphalt pavements and are often used on parking lots, car parks and driveways as a form of maintenance to extend the length of your asphalts life. Major US manufacturers include Guardtop, Overkote, and Sealmaster. Also known as asphalt emulsion or slurry seal.

Sealcoat Additives:

Additives are added to the sealer mix at the job site for numerous reasons. Some additives reduce power steering marks. Other available products enhance a sealcoating product’s resistance to oil, fuels and grease. You can also find additives to improve resistance to water.

Self-Propelled Spreaders:

Spreaders that have their own power units and two hoppers. The spreader pulls the truck as it dumps its load into the receiving hopper while conveyor belts move the aggregate forward to the spreading hopper.

Sheet Asphalt:

A hot mixture of asphalt binder with clean, angular, graded sand and mineral filler. Its use is ordinarily confined to reservoir liners and landfill caps.


A form of plastic movement resulting in bulging of the pavement.

Shrinkage Cracks:

Interconnected cracks forming a series of large blocks, usually with sharp corners or angles.

Skid Hazard:

Any condition that might contribute to the reduction of friction forces on the pavement surface.

Skid Resistance:

The ability of a paved surface to offer resistance to slipping or skidding. Proper asphalt content and aggregate with a rough surface texture are the greatest contributors. The aggregate must not only have a rough surface texture, but also resist polishing.


The degree to which a paved surface is angled.

Slippage Cracks:

Crescent-shaped cracks resulting from traffic-induced horizontal forces that are open in the direction of the thrust of wheels on the pavement surface.

Soil/Cement Base:

A hardened material formed by curing a compacted mixture of pulverized soil, cement and water used as a layer in a pavement system to reinforce and protect the subgrade or subbase.


The breaking or chipping of a cement pavement at joints, cracks,or edges, usually resulting in fragments with feather edges.

Squeegee Machine or Sealer Buggy:

Ride on application machine that applies sealcoating materials with rubber squeegees behind the unit. The rubber squeegees help push the seal coat into the voids of the asphalt.


The ability of an asphalt paving mixture to resist deformation. Stability is dependent upon both internal friction and cohesion.

Steel-Wheel Static Rollers:

Tandem or three-wheel rollers with cylindrical steel rolls that apply their weight directly to pavement.

Steel-Wheel Vibratory Rollers:

A compactor having single or double cylindrical steel rolls that apply pressure with weight and vibration. The amount of compactive force is adjusted by changing the frequency and amplitude of vibration.

Structural Overlay:

A HMA overlay constructed to increase the structural value and ride quality of the pavement system.


The soil prepared to support a pavement structure or a pavement system. It is the foundation of the pavement structure.

Superpave Mix Design:

An asphalt mixture design system that integrates the selection of materials (asphalt, aggregate) and volumetric proportioning with the project’s climate and design traffic.


Short for “Superior Performing Asphalt Pavement” a performance-based system for selecting and specifying asphalt binders and for designing asphalt mixtures.

Tack Coat:

A spray on application asphalt product used to promote bonding between new asphalt concrete and other surfaces. Most commonly used between asphalt concrete pavement layers.

Tack Coat Sprayer:

Machine used to heat and spray emulsions, asphalt rejuvenators, tack coat and more.


The result of products or materials being “picked up” by car tires, shoes, shopping cart wheels, etc. and being carried, or “tracked,” from the pavement onto surfaces where the material is not desired.

Transverse Crack:

A crack that follows a course approximately at right angles to the centerline. Can be caused by shrinkage of the HMA surface due to low temperatures or asphalt binder hardening, or reflective cracks caused by cracks beneath the surface HMA layer.


The localized upward displacement of a pavement due to swelling of the subgrade or some portion of the pavement structure.

Wedge Cut:

The process where the existing asphalt layer is ground in a wedge shape to conform to an adjacent structure such as valley gutter, ramp, or curb and gutter. Done prior to the overlay process.

Well-Graded Aggregate:

Aggregate graded with relatively uniform proportions, from the maximum size down to filler.


The ease with which paving mixtures may be placed and compacted.