The base course or basecourse in pavements is a layer of material in an

asphalt Asphalt most often refers to: * Bitumen, also known as "liquid asphalt cement" or simply "asphalt", a viscous form of petroleum mainly used as a binder in asphalt concrete * Asphalt concrete, a mixture of bitumen with coarse and fine aggregates, u ...

road A road is a thoroughfare used primarily for movement of traffic. Roads differ from streets, whose primary use is local access. They also differ from stroads, which combine the features of streets and roads. Most modern roads are paved. Th ...

way, race track, riding arena, or sporting field. It is located under the surface layer consisting of the '' wearing course'' and sometimes an extra ''binder course''. If there is a sub-base course, the base course is constructed directly above this layer. Otherwise, it is built directly on top of the subgrade. Typical base course thickness ranges from and is governed by underlying layer properties. Generally made of a

construction aggregate Construction aggregate, or simply aggregate, is a broad category of coarse- to medium-grained particulate material used in construction. Traditionally, it includes natural materials such as sand, gravel, crushed stone. As with other types of ag ...

, it is spread and compacted to at least 95% relative compaction, thus providing a stable foundation for additional layers of material. Aggregate base (AB) is typically a mix of different sizes of crushed rock '' Aggregate Base, Class 2'', is used in roadways and consists of rock particles of size and less. 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.

References

{{DEFAULTSORT:Base Course Pavement engineering Road transport Road infrastructure

See also

References