What Is A Wearing Course In Construction?

What Is A Wearing Course In Construction?

What Is A Wearing Course In Construction?

The wearing course is the top layer in the construction of roads, runways, and docks. It is sometimes referred to as the surface course, though this term can also refer to thin layers such as chip seals.

The wearing course is made of concrete in rigid pavements, while in flexible pavements it is composed of asphalt and aggregate.

The wearing course is typically placed on top of the binder course, which is in turn laid on top of the base course.

The base course is typically placed on top of the subbase, which sits on the subgrade. There are various types of flexible pavement wearing courses that are suitable for different situations.

What Is the Difference Between Asphalt Base Course And Wearing Course?

In flexible pavements, the top layer is made of asphalt concrete, which is a combination of construction aggregate and a bituminous binder.

This top layer, called the wearing course, is placed on the binder course, which is in turn laid on the base course. The base course is usually placed on the subbase, which sits on the subgrade.

The main purpose of the wearing course is to create an impervious layer that prevents water from entering the base course and to distribute the weight of traffic safely across the base course.

In rigid pavements, the base course is used for several purposes, including providing uniform and stable support, minimizing the impact of frost, facilitating drainage, preventing the pumping of fine-grained soils at joints, preventing volume changes in the subgrade, and increasing the structural capacity of the pavement.

What Are The Functions Of Wearing Course Or Surface Course Of Pavement?

The primary functions of a surface or wearing course are to:

·         Create a smooth and even surface

·         Protect against the wear and tear of traffic

·         Prevent the creation of dust

·         Serve as a structural element of the pavement.

What Is The Reason Of Failure Of Wearing Course In Flexible Pavement?

There are several types of failures that can occur in flexible pavements due to environmental distresses.

These include bleeding, where a film of asphalt binder forms over the surface of the pavement; block cracking, also known as thermal cracking, where the pavement cracks into rectangular pieces; bumps and sags, localized upward and downward displacements of the pavement surface, respectively; edge cracking, which occurs along the edges of the pavement; joint reflection cracking, cracks that occur in the flexible overlay on top of a rigid pavement; raveling, the disintegration of the asphalt surface due to the loss of bonding between the aggregate particles and the asphalt binder; and cold joints, longitudinal joints that occur when hot mix asphalt is poured next to an existing pavement.

Other types of failures include alligator cracking, which forms a pattern of interconnected cracks that resemble the skin of an alligator; potholes, small holes in the pavement surface; and shoving, the displacement of the pavement edges.