Glossary of Terms

Stone or gravel that was crushed and screened to various sizes for use in concrete, asphalt or road surfaces

Asphalt (Blacktop)
A dark brown to black cementitious material in which the predominating contents are bitumens, which occur in nature or are obtained in petroleum processing. Asphalt is a constituent in varying proportions of most crude petroleum and used for paving, roofing, industrial and other special purposes.

Asphalt Pavements
Pavements consisting of a surface course of asphalt concrete over supporting courses such as asphalt concrete bases, crushed stone, slag, gravel, or portland cement concrete.

Materials used in refilling a cut or other excavation, or the act of such refilling along the asphalt pavement edges.

The course or layer of materials in a roadway section on which the actual pavement is placed. It may be of different types of materials ranging from selected soils to crushed stone or gravel.

Finely powdered mixtures of inorganic compounds which when combined with water hardens with hydration and makes concrete as we know it.

The act of compressing a given volume of material into a smaller volume.

A hard compact building material formed when a mixture of cement, sand, gravel, and water undergoes hydration.

The process of contraction or the reflection of stress in the concrete or pavement materials.

The amount of time that concrete or asphalt pavements take to become hard and not pliable.

Finished Grade
The final grade of a finished product such as concrete, stone, topsoil or asphalt pavement.

A portion of the foundation of a structure that transmits loads directly to the soil.

The lower part of a structure that transmits loads to the soil or bedrock.

Frost Depth
The depth at which the ground becomes frozen during the winter season.

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

A mixture of cementations material and water, with or without aggregate, proportioned to produce a pour able consistency without segregation of the constituents; also, a mixture of other composition but of similar consistency. See also Neat Cement Grout and Sand Grout, but not Concrete.

Hairline Cracking
Barely visible cracks in random pattern in an exposed concrete surface which do not extend to the full depth or thickness of the concrete, and which are due primarily to drying shrinkage.

Upward movement of ground caused by tree roots, blasting, excavation and acts of nature.  This can also happen in asphalt pavements due to swelling of the sub grade or some portion of the pavement structure

Hot Mix Asphalt
High quality, thoroughly controlled hot mixture of asphalt binder (cement) and well-graded, high quality aggregate, which can be used for driveways, roads and parking lots.

Hot Mix Asphalt (HMA) Overlay
A layer of surface asphalt paved over an existing driveway, road or parking lot.

A plane of weakness to control contraction cracking in concrete pavements. A joint can be initiated in plastic concrete or green concrete and shaped with later process.

Moisture Barrier
A vapor barrier used under concrete to deter moisture vapor transmission migration.

Pavement Base
The lower or underlying pavement course atop the sub base or sub grade and under the top or wearing course.

Pavement Surface
The top layer of paving over subbase or pavement base.

Pavement Structure
The entire pavement system of selected material from sub grade to the surface.

Pounds per square inch; a measure of the compressive, tensile or flexural strength of concrete as determined by appropriate test.

Reclaimed Asphalt Pavement (RAP)
Excavated and milled asphalt pavement that has been crushed into nominal sizes and is used like an aggregate in the recycling of asphalt pavements.

When an area has lowered in grade due to failure of sub-base materials.

The course in the asphalt pavement structure immediately below the base course. If the sub grade soil has adequate support, it may serve as the sub base.

The surface produced by grading native earth, or imported materials which serve as a base for more expensive paving. Necessary for concrete and asphalt finished road materials. Sub-base is also soil prepared and compacted to support a structure, slab or pavement system.