Base course
Encyclopedia
Base Course in pavements refers to the sub-layer material of an asphalt
road
way and is placed directly on top of the undisturbed soil so as to provide a foundation to support the top layer(s) of the pavement. Generally consisting of a specific type of construction aggregate
, it is placed by means of attentive spreading and compacting to a minimum of 95% relative compaction, thus providing the stable foundation needed to support either additional layers of aggregates or the placement of asphalt concrete which is applied directly on top of an asphalt sealed Base Course, all resulting in a roadway pavement.
Aggregate Base
(AB) is typically made of a recipe of mixing different sizes of crushed rock together forming the Aggregate which has certain desirable properties. 3/4 inch Aggregate Base, Class 2, is used in roadways and is an aggregate made of a specific recipe of different sizes and quality of rock inclusive of 3/4 in to fine dust. An aggregate is normally made from newly quarried rock, or it is sometimes allowed to be made from recycled asphalt concrete and/or Portland cement concrete.
Aggregate Base is used as the base course under asphalt concrete pavement roadways, under Portland cement
concrete slabs and structural foundations, and as backfill material for underground pipelines and other underground utilities within a roadway.
Aggregate Base Course is often referred simply as ABC.
Asphalt
Asphalt or , also known as bitumen, is a sticky, black and highly viscous liquid or semi-solid that is present in most crude petroleums and in some natural deposits, it is a substance classed as a pitch...
road
Road
A road is a thoroughfare, route, or way on land between two places, which typically has been paved or otherwise improved to allow travel by some conveyance, including a horse, cart, or motor vehicle. Roads consist of one, or sometimes two, roadways each with one or more lanes and also any...
way and is placed directly on top of the undisturbed soil so as to provide a foundation to support the top layer(s) of the pavement. Generally consisting of a specific type of construction aggregate
Construction Aggregate
Construction aggregate, or simply "aggregate", is a broad category of coarse particulate material used in construction, including sand, gravel, crushed stone, slag, recycled concrete and geosynthetic aggregates. Aggregates are the most mined material in the world...
, it is placed by means of attentive spreading and compacting to a minimum of 95% relative compaction, thus providing the stable foundation needed to support either additional layers of aggregates or the placement of asphalt concrete which is applied directly on top of an asphalt sealed Base Course, all resulting in a roadway pavement.
Aggregate Base
Aggregate base
Aggregate base is typically composed of crushed rock capable of passing through a rock screen. The component particles will vary in size from 3/4 inch down to dust...
(AB) is typically made of a recipe of mixing different sizes of crushed rock together forming the Aggregate which has certain desirable properties. 3/4 inch Aggregate Base, Class 2, is used in roadways and is an aggregate made of a specific recipe of different sizes and quality of rock inclusive of 3/4 in to fine dust. An aggregate is normally made from newly quarried rock, or it is sometimes allowed to be made from recycled asphalt concrete and/or Portland cement concrete.
Aggregate Base is used as the base course under asphalt concrete pavement roadways, under Portland cement
Portland cement
Portland cement is the most common type of cement in general use around the world because it is a basic ingredient of concrete, mortar, stucco and most non-specialty grout...
concrete slabs and structural foundations, and as backfill material for underground pipelines and other underground utilities within a roadway.
Aggregate Base Course is often referred simply as ABC.