Paving Guide

Sable Asphalt’s Paving Guide


AGGREGATE – A hard mineral material used for mixing in graduated fragments like sand, gravel, crushed stone, or slag.

ASPHALT BASE COURSE – The foundation course, which consists of mineral aggregate, bound together with asphaltic material.

ASPHALT BINDER COURSE – The intermediate course between a base course and an asphalt surface course. The binder course is usually a coarse-graded aggregate Asphalt Concrete containing little or no mineral matter.

ASPHALT JOINT FILLER – Used for filling cracks and joints in pavement and other structures.

ASPHALT OVERLAY – One or more courses of asphalt construction on an existing pavement. This resurfacing generally includes a leveling course to correct the old pavement, followed by a uniform course(s) to provide needed thickness.

ASPHALT SOIL STABILIZATION – A soil treatment of clay-based soils (or “plastic” soil) with liquid asphalt at normal temperatures. After mixing, the aeration and compaction will provide a water resistant base and sub base with improved load-bearing qualities.

ASPHALT SURFACE TREATMENTS – Applications of asphaltic materials to any type of road or pavement surface, with or without a cover of mineral aggregate, which will increase the thickness by less than I inch.


BASE COURSE – The layer directly under the surface or intermediate course. It might be made of asphaltic material, crushed stone; crushed slag; crushed or uncrushed gravel and sand; or combinations of these materials.

BINDER COURSE –It’s the transitional layer of paving between the base and the surface course.


COAL TAR SEAL – Coal tar sealer shields asphalt surfaces from damaging weather and protects against the effects of chemicals and petroleum products.

CUTBACK ASPHALT – Asphalt cement that has been liquefied by blending with petroleum based solvents. After exposure to the atmosphere, the solvent evaporate, and the asphalt cement ready to use.


DEEP LIFT ASPHALT – A pavement in which the base course is placed in one or more lifts of 4 or more inches compacted thickness.

DESIGN THICKNESS – The total pavement structure thickness above the sub grade.

DRAINAGE – Structures that facilitate the collection and carrying away water.


EMULSIFIED ASPHALT – The emulsion of asphalt cement and water that contains a little bit of an emulsifying agent, Emulsified asphalts may be either anionic (electro-negatively-charged asphalt globules) or cationic (electro-positively-charged asphalt globules) depending upon the emulsifying agent.


FREE WATER – Ground water that is able to move through soil under the influence of gravity

FRENCH DRAIN – A trench loosely backfilled with stones, the largest being placed on the bottom with the size decreasing toward the top.

FULL-DEPTH ASPHALT PAVEMENT – An asphalt pavement in which asphalt mixtures are employed for all courses above the sub grade or improved sub grade. A full-depth asphalt pavement is laid directly on the prepared sub grade.


GRAVEL – A coarse granular material that is the result of natural erosion and disintegration of rock. Crushed gravel is the result of artificial crushing.


IMPROVED SUBGRADE – Any course of select or improved material between the foundation soil and the sub base is referred to as the improved sub grade. It can be made up of two or more courses of different quality materials.


LEVELING COURSE – An asphalt/aggregate mixture used to eliminate irregularities in the contour of an existing surface before further treatment or construction.

LIQUID ASPHALT – An asphalt material with a soft or fluid consistency that is beyond the range of measurement by the normal penetration test. Liquid asphalts include cutback asphalt and emulsified asphalts.


MEDIUM CURING ASPHALT (MC) – Liquid asphalt composed of asphalt cement and a kerosene-type diluent of medium volatility, which decreases the viscosity of the fluids.


NATURAL ASPHALT – Asphalt that occurs in nature, but has been derived from petroleum by natural processes of evaporation of volatile fractions, which leaves the asphalt fractions.


PAVEMENT STRUCTURE – All courses of material placed on the foundation or sub grade soil, other than any layers or courses constructed in grading. When the asphalt pavement is on a rigid-type base, the pavement structure is referred to as a combination or composite-type pavement structure.

PRIME COAT – The application of low viscosity liquid asphalt to an absorbent surface. It’s used to prepare an untreated base for an asphalt surface.


RAPID CURING ASPHALT (RC) – Liquid asphalt made of asphalt cement and a high volatility diluent.

RECLAIMED ASPHALT PAVEMENT (RAP) Removed and/or reprocessed pavement materials that contains asphalt and aggregates.

REHABILITATION – The renewal of an existing surface or structure by repair, recycling, or overlay techniques.

RESURFACING – Existing surfaces may be improved by resurfacing (or overlaying) with a plant mix asphalt mat of varying thicknesses. There are two kinds: 1) overlays that provide smooth, skid- and water resistant surfaces or make improvements in grade; and 2) overlays that strengthen the existing pavement to handle heavier loads or more traffic. Resurfacing is also called an overlay.


SEAL COAT – A thin asphalt surface treatment used to waterproof and improve the texture of an asphalt surface. Seal coats may or may not be covered with aggregate, depending on the purpose. The main types of seal coats are aggregate seals, fog seals, emulsion slurry seals, and sand seals.

SLOW CURING ASPHALT (SC) – Liquid asphalt made of asphalt cement and oils of low volatility.

SOIL AGGREGATE – Natural or prepared mixtures of hard particles or fragments of stone, slag, gravel, or sand, that contain some soil-clay or stone dust depending on specified requirements.

SOIL SUPPORT – The ability of the roadbed material, or sub grade soil, to support the traffic weight that is transmitted through flexible pavement.

STONE MASTIC ASPHALT – A high quality surface asphalt mix with a high content of asphalt through the use of fiber fillers. Only very high quality aggregates are used.

SUBBASE – The course immediately below the base asphalt pavement course is the sub base. If the sub grade soil is good quality, it can serve as the sub base..

SUBDRAIN – A structure under the ground surface that collects and carries away underground water.

SUB GRADE – The foundation for the asphalt pavement structure, which is sometimes called basement soil or foundation soil.

SURFACE COURSE – One or more layers of pavement designed to accommodate traffic. The top layer resists skidding, traffic abrasion, and the disintegrating effects of weather.

SUB SURFACE DRAINAGE – Removal of free water from parts of the pavement or the surrounding soil.


UNDERDRAIN – A porous-walled pipe placed beneath the ground surface to collect and carry away underground water.


VISCOSITY – The measure of resistance to flow. A low viscosity material refers to a light liquid material that flows easily. A high viscosity material is the opposite.


WEARING COURSE – The top course of asphalt pavements, which is also called the surface course.