What is the difference between base course and wearing course?

The wearing course is the upper layer in roadway, airfield, and dockyard construction. 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.

What is a bituminous base course?

DESCRIPTION: Bituminous surface and base courses shall consist of fine and coarse aggregates and mineral filler uniformly mixed with hot bituminous material, and placed and compacted on a prepared base as specified within the City of Warrensburg standard specifications.

What is asphaltic wearing course?

“asphalt wearing courses” is that part of the pavement upon which the traffic travels including any dense graded asphalt course immediately below a course of open graded asphalt. “asphalt pavement” is a pavement, the predominate structural strength of which is provided by asphalt layers.

What is the purpose of binder course?

Binder courses are designed to withstand the highest shear stresses that occur about 50 – 70 mm below the asphalt surface. The binder course is therefore placed between the surface course and base course to reduce rutting by combining qualities of stability and durability.

What is the thickness of wearing course?

The layer thickness of a wearing course including the anti-slip aggregate is only 7-10 mm. That has a big impact on the weight. The weight increase using asphalt is high with approximately 250 kg per m2. When applying a wearing course the weight increase is 15-18 kg per m2.

What is base course material?

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 course.

Is concrete a good base for asphalt?

1. A Concrete Driveway Sub Base Is Different Than an Asphalt Driveway Sub Base. The big problem with laying asphalt driveways over concrete has to do with the initial preparation of the site. With concrete, if you’re concerned about strength and stability, the solution is to simply lay a thicker slab.

How much is a base course?

A minimum of 100 mm of compacted base course (AP20) is required for under paving, this may need to be thicker in some situations (a stable concrete pad can be used instead of base course). Area to be paved (m2) x 0.1 (allows for 100mm of base course) x 1.3 (allows for compaction) = m3 of base course required.

What is the function of wearing course?

Surface (or Wearing) Course: This is the topmost layer; its function is to provide a smooth, strong, abrasion-resistant and reasonably impervious course. Since it is directly in contact with the vehicle tyres, it has to resist the imposed wheel loads and transmit them safely to the layer below.

Is asphalt better than concrete?

Concrete is more durable than asphalt. Because it is a less flexible material, it cracks in freezing temperatures, and many people turn to concrete patching products. Though it is more durable overall, when damages do occur, concrete repair is harder and costlier. than asphalt repair.

What is the minimum thickness of wearing course?

It is constructed with hard and durable aggregates which may either stabilized or granular or both. The thickness of base course must be great enough to reduce the load capacity on sub-grade and Subbase courses. The minimum base course thickness recommended is 100 mm.

What is the maximum limit of subgrade thickness?

Explanation: The prepared sub grade is limited to a maximum of 300 mm, in any case it must not exceed 300 mm. Explanation: The base course is laid for a thickness of 100 mm, it may exceed in some cases, in some cases it may be 80 mm and even 40 mm in unimportant roads.

What kind of bitumen is used for a binder course?

The material used as a binder course is ‘chunkier’ than a wearing course, usually comprising 20mm or 28mm aggregate in a bitumen binder, known as Dense Bitumen Macadam (DBM). On public highways and other heavier-use projects, the binder course may be underlain by a base layer.

What does a bituminous surface treatment ( BST ) do?

A bituminous surface treatment (BST), also known as a seal coat or chip seal, is a thin protective wearing surface that is applied to a pavement or base course. BSTs can provide all of the following: A waterproof layer to protect the underlying pavement. Increased skid resistance.

How big should a base layer be for a binder course?

On public highways and other heavier-use projects, the binder course may be underlain by a base layer. For binder course 50-80mm thick, use 20mm material (DBM) For binder course 70-150mm thick, use 28mm material (DBM) 20mm Binder Course

Can a base course be constructed from more than one layer?

The sub-base and base courses may be constructed from more than one individual layer of the specified material, but for our purposes, we will consider each layer as being a single entity. Sometimes, levels permitting , an existing bitmac or concrete surface can be overlaid with a new surface course.