Paving Terms Glossary

Alligator Cracking

This prevalent type of cracking earned its name from the similar appearance of the rough and scaled skin of an alligator. Minor alligator cracking is usually repaired with a pavement overlay, while areas with more severe cracks require asphalt crack repair.

Americans with Disabilities Act (ADA)

A federal law passed in 1990, the ADA aims to guarantee construction and design standards in all structures to benefit those with disabilities. The standards used by Pavemax regulate access aisles, curb ramps, parking space marking and sizes, and more. States and municipalities generally also have regulations that augment the ADA.

Aggregates

Various-sized crushed rock, gravel, and stones that make up the majority — up to 96 percent — of the asphalt mixture.

Asphalt

Officially known as bituminous asphalt concrete, asphalt is a blend of aggregates and hot asphalt cement. Asphalt goes through placement, compaction, and cooling before the surface is ready for use. Flexible pavement is another name for asphalt.

Asphalt Base

An asphalt mix that limits stones to 3/4 inch in size. The base mix is laid over at least two inches of a compacted stone base.

Asphalt Binder

An asphalt binder is used between the aggregate base layer and surface layer used by pedestrians and/or vehicles.

Asphalt Cement

The glue that holds pavement together, asphalt cement is made from a petroleum byproduct and makes up between 4 percent and 8 percent of a pavement mixture.

Asphalt Overlay

Also called resurfacing, an asphalt or paving overlay is commonly used to replace sections of an asphalt surface while the remainder of the area stays intact. Damaged asphalt is milled and cleaned before a 1.5-inch to 2-inch layer of hot mix asphalt is laid down over the existing surface. Overlays are commonly used to extend the functional life of an asphalt surface that doesn’t yet need complete reconstruction.

Base

The base is the material, such as crushed asphalt or stone product, that is installed before the asphalt. This layer is responsible for bearing the weight of any load placed on the surface. It’s important to determine the appropriate type and amount of base material before paving begins to ensure a base that is structurally sound.

Base Failure

When the layer between the binder and the surface is unable to sufficiently support the surface weight, a base failure usually results. The cause of the failure may be wide and varied, including excessive weight, exposure to groundwater, and improper initial design. A paving company in Florida, such as Pavemax, can repair the situation by removing the failed base and replacing the material with a bridging stone.

Blacktop

Blacktop is likely the most common term used to describe asphalt. Yet, it carries different meanings depending on location and shouldn’t be used when asking for asphalt pavement.

Cold In Place Recycling (CIPR)

CIPR grinds recycled pavement into an aggregate for new paving base material and uses an additive, such as emulsions, to stabilize the mix.  

Chip Seal

A chip seal lays a hot asphalt layer over an existing surface then rolls in a layer of small crushed aggregate. Chip seal is rarely used for parking lot repairs due to the chance of oil tracking in high temperatures.

Coal Tar

Coal tar is a byproduct of steel production and was used for many years as a primary component in asphalt sealcoating. However, many Florida paving companies have phased out its use, including Pavemax, due to concerns over health issues caused by exposure.

Compaction

The physical act of forcing the air from the subgrade and base before applying the asphalt layer. Adequate compaction is necessary to create a solid base.

Complete Reconstruction

Removal and rebuilding of an irreparably damaged asphalt surface. All parts of the surface are removed down to the base layer before applying the new base, subgrade, and asphalt. Complete reconstruction usually isn’t necessary until late in the pavement life cycle.

Concrete

Formed from a blend of cement, gravel, sand, and water, concrete is also known as Portland cement concrete pavement. This type of building material is frequently used for curbs, delivery docks, and sidewalks.

Course Asphalt Base

Mineral aggregate binds together with asphalt material to form a base course.

Course Asphalt Surface

Also called asphalt wearing course, this is the top course of pavement.

Cracking

Asphalt cracks, or separates, when subjected to age, excessive loads, and/or prolonged exposure to high heat.

Deflection

A difference in the actual pavement load capacity from the determined profile.

Density

Density refers to the layers of the asphalt structure thickness achieved through compaction. Generally, the density is outlined in a contractor’s bid and/or contract.

Drainage

Drainage refers to the system of drains and pipes that move surface water from the asphalt structure. The better designed a drainage system is, the less likely the asphalt base will be affected and weakened by water.

Emulsion

Emulsions are a blend of mechanically combined ingredients that otherwise don’t mix together.

Fog Seal

A diluted asphalt emulsion is applied to a roadway surface as a fine spray, mimicking fog. This protective seal can repair hairline cracks in the surface while reinvigorating the stark black appearance of the asphalt.

Geotextiles

Fabric-like materials used between the base, subgrade, and asphalt layers to improve stability.

Grade

Grade, or slope, is the angled degree of a paved surface and helps drain water from the surface.

Heat Lance

This tool combines and ignites compressed air and propane to produce a directed, high-velocity stream of air. The air removes debris from pavement cracks to prepare the area for repair and sealing.

Hot Mix Asphalt Concrete (HMAC)

The official name for asphalt, HMAC is produced with a range of grades, from coarse aggregate mix to specialized mix typically used in repairs and resurfacing.

Infrared Repair

An efficient and effective method of repair, infrared repair essentially spot treats damaged asphalt instead of full-scale replacements. The damaged pavement is heated to at least 300 degrees Fahrenheit, then raked and mixed with a rejuvenator and new hot asphalt mix, as needed. The area can be used in as little as 30 minutes after compaction.

International Symbol of Accessibility (ISA)

This is the appropriate term for what is commonly called the handicap symbol, signified by the wheelchair design and used globally to indicate areas accessible by people with disabilities.  

Joints

Also called an asphalt seam, an asphalt joint is a usually visible line where two sections of asphalt meet.

Laydown

Placement of hot asphalt in a specified area using a paving machine.

Patching

Patching, or digouts, removes and replaces all old and damaged patches of pavement. A small perimeter is cut around the damaged area and the section is removed down to the base. The base is compacted before new asphalt is poured. Asphalt patching normally doesn’t occur until stage 3 or stage 4 in the pavement life cycle but improves the entire asphalt structure.

Paver or Paving Machine

Equipment used to place asphalt or concrete in its final position during installation. A paving machine creates a consistent, even finish and initial compaction for the surface.

Prime Coat

A prime coat seals the subgrade and/or base to enhance the bonding capability of the asphalt layer. This material may be made from asphalt oil or a specialized emulsion.

Reclaimed Asphalt Pavement (RAP)

RAP, or recycled pavement, is existing, damaged asphalt ground into a smaller aggregate and added into new hot asphalt mix. It has become exceedingly common due to economic and environmental reasons and is regularly used by Pavemax, a green-company in Florida.

Reflective Cracking

Reflective cracking occurs when secondary cracks in an asphalt surface are visible through the existing cracks. But a professional paving company, such as Pavemax, can use specialized materials and techniques to reduce reflective cracking.

Routing

The mechanical enlargement of pavement cracks in preparation of crack sealing. Routing produces an appropriate depth to width ratio to increase the durability and effectiveness of the repair.

Sealcoating

Asphalt sealcoating uses a combination of asphalt mixture, mineral fillers, various additives that strengthen the sealer and speed up the drying process, and water. This process is the last step after new asphalt has been installed and can only be done once the asphalt has cured. A sealcoat stops water from penetrating the pavement surface while slowing oxidation and naturally occurring wear.

Slurry Seal

A type of sealcoating generally applied to roads and streets, the slurry seal is produced as it’s applied to the surface. The mixture is made from additives, an aggregate slurry seal, and graded asphalt emulsion.

Strategic Highway Research Program (SHRP)

An in-depth, multi-year federal research project, which has produced the majority of data and information used to create long-lasting paving designs, materials, and methods.

Subgrade

The foundation for any asphalt pavement, the subgrade refers to the prepared soil underneath the layers of the asphalt structure.

Subgrade Failure

Subgrade failures occur when the soil beneath the asphalt is unable to properly support the surface loads. Exposure to groundwater and excessive load weight are two frequent reasons for subgrade failure. The failure can be repaired by excavating and replacing the failed soil with a new base.

Superior Performing Asphalt Pavement (SPAP)

Also called Superpave, SPAP is a type of asphalt design theory that aims to design asphalt structures specifically for the environment in which they will be located.

Surface

The top layer of an asphalt structure, the surface features a minimum depth of one inch of asphalt mix when compacted.

Tack Coat

An emulsion of asphalt oil used to bond new and old asphalt together during overlay paving or repairs.

Tracking

This term refers to asphalt material picked up by shoes, tires, or another movement-related activity which moves the material to an undesired location, such as inside a building. Tracking is common in high temperatures as the asphalt surface weakens due to heat exposure.

Traffic Index Rating

A numerical measurement given to an asphalt surface based on load factors such as traffic distribution, vehicle speed, load repetition, and tire loads. The traffic index rating directly affects how the asphalt surface is designed and installed.

Transverse Crack

Breaks or cracks in the asphalt that generally span the width of the surface, or otherwise form a 90-degree angle to the direction of the asphalt placement.

Wedge Cut

Existing asphalt is ground to form a wedge shape to accommodate a curb and gutter, ramp, or another adjacent structure during a pavement overlay.