Paver base is a form of

aggregate Aggregate or aggregates may refer to: Computing and mathematics * collection of objects that are bound together by a root entity, otherwise known as an aggregate root. The aggregate root guarantees the consistency of changes being made within the ...

used in the construction of

patios A patio (, from es, patio ; "courtyard", "forecourt", "yard", "little garden") is an outdoor space generally used for dining or recreation that adjoins a structure and is typically paved. In Australia the term is expanded to include roofed stru ...

and

walkways In American English, walkway is a composite or umbrella term for all engineered surfaces or structures which support the use of trails. ''The New Oxford American Dictionary'' also defines a walkway as "a passage or path for walking along, esp. a ...

whose topmost layer consists of mortarless (or "dry-laid") pavers. The first layer in the construction of such a surface is called the

subgrade In transport engineering, subgrade is the native material underneath a constructed road,http://www.highwaysmaintenance.com/drainage.htm The Idiots' Guide to Highways Maintenance ''highwaysmaintenence.com'' pavement or railway track (US: railroad ...

—this is the layer of native material underneath the intended surface. It is usually compacted and stabilized. If the final pavement is to have vehicle traffic, a layer of

subbase In topology, a subbase (or subbasis, prebase, prebasis) for a topological space X with topology T is a subcollection B of T that generates T, in the sense that T is the smallest topology containing B. A slightly different definition is used by so ...

of crushed stone or concrete must come next—this layer will even out the subgrade and will bear the heaviest load from the pavement above. Next comes the

base course The base course or basecourse in pavements is a layer of material in an asphalt roadway, race track, riding arena, or sporting field. It is located under the surface layer consisting of the ''wearing course'' and sometimes an extra ''binder cour ...

(also called the aggregate base course or ABC) composed of crushed gravel varying from down to dust-particle size. It too is typically compacted and evened. The next layer will be the paver base, composed of coarse

sand Sand is a granular material composed of finely divided mineral particles. Sand has various compositions but is defined by its grain size. Sand grains are smaller than gravel and coarser than silt. Sand can also refer to a textural class of s ...

and typically between thick, depending on anticipated traffic. The pavers are then laid on top of this, and then a uniform, fine-grained sand is poured between them.

References

{{reflist Building materials