The wearing course is the upper layer in roadway, airfield, and dockyard construction. The term 'surface course' is sometimes used, however this term is slightly different as it can be used to describe very thin surface layers such as
chip seal
Chipseal (also chip seal or chip and seal) is a pavement surface treatment that combines one or more layer(s) of asphalt with one or more layer(s) of fine aggregate. In the United States, chipseals are typically used on rural roads carrying lo ...
. In
rigid pavement
Highway engineering is an engineering discipline branching from civil engineering that involves the planning, design, construction, operation, and maintenance of roads, bridges, and tunnels to ensure safe and effective transportation of people and ...
s the upper layer is a
portland cement concrete slab. In
flexible pavements, the upper layer consists of
asphalt concrete
Asphalt concrete (commonly called asphalt, blacktop, or pavement in North America, and tarmac, bitumen macadam, or rolled asphalt in the United Kingdom and the Republic of Ireland) is a composite material commonly used to surface roads, parkin ...
, that is a
construction aggregate
Construction aggregate, or simply aggregate, is a broad category of coarse- to medium-grained particulate material used in construction, including sand, gravel, crushed stone, slag, recycled concrete and geosynthetic aggregates. Aggregates ...
with a
bituminous binder. The wearing course is typically placed on the binder course which is then laid on the
base course, which is normally placed on the
subbase, which rests on the
subgrade. There are various different types of flexible pavement wearing course, suitable for different situations.
Stone mastic asphalt is a type of flexible pavement wearing course which is typically used for heavily trafficked roads.
See also
*
Highway engineering
*
Road construction
*
Road surface
A road surface (British English), or pavement (American English), is the durable surface material laid down on an area intended to sustain vehicular or foot traffic, such as a road or walkway. In the past, gravel road surfaces, hoggin, cobbles ...
References
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Pavement engineering
Road infrastructure