Wearing course

<p>The wearing course, also known as a friction course or surface course, is the upper layer in roadway, airfield, and dockyard construction. The term 'surface course' is sometimes used slightly different, to describe very thin surface layers such as <a href="/facts/Chip_seal/ww1cJ31F">chip seal</a>. In <a href="/facts/Rigid_pavement/RUcu1E8n">rigid pavements</a> the upper layer is a <a href="/facts/Portland_cement_concrete/kPj8EjnP">portland cement concrete</a> slab. In <a href="/facts/Flexible_pavement/RUcu1E8n">flexible pavements</a>, the upper layer consists of <a href="/facts/Asphalt_concrete/TTp7fXA6">asphalt concrete</a>, that is a <a href="/facts/Construction_aggregate/K7XM0BAg">construction aggregate</a> with a <a href="/facts/Bituminous/tW6EqphW">bituminous</a> binder. The wearing course is typically placed on the binder course which is then laid on the <a href="/facts/Base_course/zFdeJNMI">base course</a>, which is normally placed on the <a href="/facts/Subbase_(pavement)/M7vbYyYp">subbase</a>, which rests on the <a href="/facts/Subgrade/QEMKH2sM">subgrade</a>. There are various different types of flexible pavement wearing course, suitable for different situations.
</p><p><a href="/facts/Stone_mastic_asphalt/mwuL0fUj">Stone mastic asphalt</a> is a type of flexible pavement wearing course which is typically used for heavily trafficked roads.
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Wearing course open-in-new

Wearing course