Glossary

Asphalt concrete (AC)—Asphalt concrete is a paving material comprised of a mixture of asphalt cement binder, aggregates, and admixtures. It is understood that different asphalt mixtures may be referred to differently, such as hot mix, warm mix, stone matrix asphalt, and so on. In this report, asphalt or asphalt concrete is used to refer to a generic surface mixture without regard for its actual composition.

ASTM D5078, Standard Specification for Crack Filler, Hot-Applied, for Asphalt Concrete and Portland Cement Concrete Pavements.

ASTM D6690, Standard Specification for Joint and Crack Sealants, Hot Applied, for Concrete and Asphalt Pavements.

ASTM D8260, Standard Specification for Hot-Applied Asphalt Aggregate-Filled Mastic.

Chip seal—A combination of graded stone (chips) placed over either liquid-emulsified asphalt or hot-applied binder sprayed on the pavement surface. The surface is rolled to enable seating of chips.

Crack filling—Placing sealant material in cracks that do not experience movement or nonworking cracks. These are typically longitudinal cracks that in some cases are only cleaned before being sealed. Crack filling materials are defined in ASTM D5078, Standard Specification for Crack Filler, Hot-Applied, for Asphalt Concrete and Portland Cement Concrete Pavements.

Crack sealing—Placing sealant material in or over cracks that experience movement (also referred to as working cracks). These are typically transverse cracks that open and close due to daily and seasonal temperature changes. Crack sealing is often performed on cracks that are routed and cleaned, using sealing materials that have good adhesion, cohesion, and elasticity characteristics when exposed to repeated crack opening and closing. Crack sealing materials are defined in ASTM D6690, Standard Specification for Joint and Crack Sealants, Hot Applied, for Concrete and Asphalt Pavements.

Fog seal—A spray-applied asphalt emulsion placed over a pavement surface to improve aggregate retention, slow weathering and raveling, and improve appearance.

Longitudinal crack—A crack running approximately parallel to the pavement centerline. These often occur at the joint between asphalt paving lanes and may be referred to as longitudinal paving joints, longitudinal cold joints, or longitudinal joints. A longitudinal crack may also be a reflection of a crack or joint in the underlying pavement.

Mastic—Pavement mastics are a combination of polymer-modified asphalt binder and lightweight aggregate extender which are heated in a specialized melter and placed using either an applicator or a mastic pot to patch gaps in the pavement surface. Mastics are flexible and

have strong bonding and load-bearing capabilities. Pavement mastic materials are defined in ASTM D8260, Standard Specification for Hot-Applied Asphalt Aggregate-Filled Mastic.

Micro surface—A micro surface treatment is a combination of polymer-modified asphalt emulsion, mineral aggregate, mineral filler, water, and other additives that is spread over some portion or all of the pavement surface. A micro surface treatment differs from a slurry seal in that it undergoes a chemical set and can be placed multiple stones thick. As such, it can be used to fill wheelpath ruts or for other narrow patching applications. Micro surface is also referred to as micro-surface or microsurfacing.

Mill and fill—Also referred to as mill and patch, mill and replace, or slot paving, this is a process in which a narrow band (1 to 3 feet) of the pavement surface over a crack is removed with a milling machine up to 2 inches deep and the resulting slot is patched with asphalt material.

Seal coat—A general term referring to various surface treatments applied to a pavement surface. The term is used by some synonymously with chip seals. See surface treatment.

Slurry seal—Similar to a micro surface, a slurry seal is a combination of a slow-setting emulsified asphalt, fine aggregate, mineral filler, and water applied over a pavement surface. Unlike micro surfaces, slurry seals are placed during daylight hours and undergo a temperature cure. They are also only placed approximately one stone thick. Slurry seals fill small cracks, restore surface texture, seal the pavement surface to slow aging, and can improve skid resistance.

Spray patch—A pavement patching technique in which a specialized piece of equipment is used to blow out a hole in the pavement surface, apply a tack coat, and repair the hole or defect with a blend of asphalt emulsion and aggregate. Also referred to as blow patch and spray injection patch.

Surface treatment—Another general term referring to various thin surfacings applied to a pavement surface. In some instances, the term is used synonymously with chip seals. See seal coat.

Transverse crack—A crack in the pavement surface running approximately perpendicular to the pavement centerline. These may be thermal or temperature cracks, reflection cracks of joints, or cracks in the underlying pavement.

Source

In addition to author-written descriptions, the following source was considered:

FHWA. 2018. Glossary of Terms for DOJ/FHWA Joint Technical Assistance on the ADA Title II Requirements to Provide Curb Ramps When Streets Roads or Highways Are Altered Through Resurfacing. Federal Highway Administration, Washington, DC.