Glossary of Terms

Aggregate

A hard, inert mineral material, such as gravel, crushed rock, sand, or crushed stone, used in pavement applications either by itself or for mixing with asphalt.

Asphalt binder

The principal asphaltic binding agent in HMA. “Asphalt binder” includes asphalt cement as well as any material added to modify the original asphalt cement properties.

Asphalt cement

A derivative of crude oil refining that is the binder or “glue” in the asphalt pavement mixture. This term is no longer used, see Asphalt Binder.

Asphalt pavement (hot mix asphalt)

A high-quality, thoroughly controlled, engineered mixture made by heating asphalt cement and mixing it with aggregates and mineral fillers. Typical proportions are 94 to 96 percent aggregate and 4 to 6 percent asphalt cement.

Asphalt rubber binder (AR)

Recycled ground tire rubber is added to conventional asphalt cement. Factory-reject roofing shingles may also be added to the asphalt cement.

Binder

The “glue” that holds a pavement together. In asphalt pavements, it is asphalt cement. It may be modified with polymers to improve its properties.

Crumb rubber

Asphalt rubber binder with a consistency ranging from coffee grounds to peanut butter.

DMF (Design Mix Formula)

A Design Mix Formula is a recipe for the composition of a hot mix asphalt mixture including sources, components, preparation requirements and final properties.

ESAL (Equivalent Single Axle Load)

The most common approach to determining traffic loading is to convert wheel loads of various magnitudes and repetitions to an equivalent number of “standard” or “equivalent” loads. The most commonly used equivalent load in the U.S. is the 18,000 lbs. (80 kN) equivalent single axle load.

Hot mix asphalt (HMA)

A high-quality, thoroughly controlled, engineered mixture that is made by heating asphalt cement and mixing it with aggregates and mineral fillers that can be compacted into a uniform dense mass.

Hot mix asphalt (HMA) overlay

One or more courses (layers) of HMA over an existing pavement.

HMA Certified Plants

A listing of those HMA Plants that have been “certified” by INDOT. The “certification program” places demonstrated assigned responsibilities on the producer, assuring both personnel and plant meet expected training and proficiencies. The program is administered by INDOT relieving locals and others of this responsibility.

Maintenance mix

A mixture of asphalt emulsion and mineral aggregate used in relatively small areas to patch holes, depressions, and distressed areas in existing pavements.

Mineral fillers

Sand and fine particles of mineral material that exhibit specific characteristics that are helpful in the design and construction of asphalt pavements.

Pavement base

The lower or underlying pavement course atop the subbase or subgrade (natural earth) and under the top or wearing course.

Reclaimed asphalt pavement (RAP)

Asphalt paving material that has been removed from a road or highway and crushed for reuse or recycling into new pavements.

Recycled asphalt mix

A mixture produced by processing reclaimed asphalt pavement into new pavement. Materials such as roofing shingles, glass, foundry sand, and slag can also be incorporated into asphalt pavements.

SuperPave

SuperPave is a Hot Mix Asphalt (HMA) product used by most State DOT’s specially designed to meet specific geographical and design load criteria. J.H. Rudolph uses SuperPave HMA in every paving project.