What is sub base material?

What is sub base material?

Sub-base material is produced by crushing either limestone or granite rock. The sub base is designed to evenly spread the load on traffic bearing areas such as pavements and roads. Made up of a load-bearing layer of aggregate, the sub base is laid on the sub-grade layer below.

What is a subgrade material?

In transport engineering, subgrade is the native material underneath a constructed road, pavement or railway track (US: railroad track). It is also called formation level. The term can also refer to imported material that has been used to build an embankment.

What is sub base and base?

Base may consist of unbound materials, such as gravel or crushed stone, or stabilized materials, such as asphalt-, cement- or lime-treated materials. The subbase course is typically a granular borrow that is placed between the base and subgrade. It can be constructed as either a treated or untreated layer.

What is the purpose of sub base?

The function of a subbase is to help prevent pumping of fine-grained, subgrade soils. Pumping, which leads to the loss of soil material beneath slab edges and joints, occurs when three factors exist in combination: pumpable soils, excess water under the pavement, and frequent heavy truck loads.

How does sub-base work?

A sub-base works by distributing a point load over a larger area. The interlock between adjacent particles of the sub-base material ensures that a relatively thin layer of the right sort of crushed aggregate can dramatically improve the ability of the ground to carry comparatively heavy loads.

What is subgrade and base?

A subgrade is made up of native soil that has been compacted to withstand the loads above it. There is no consistency in regards to the terms of subbase and subgrade, but normally the subgrade is the native soil while the subbase is the layer of soil or aggregate on top of the subgrade.

What are sub grades and sub bases in concrete slabs?

Subgrade and subbase are the foundation of a concrete slab and play critical role in its performance. According to the ACI Code, the subgrade is a compacted and improved natural soil or brought infill whereas subbase is a layer of gravel placed on the top of the subgrade.

What is a base material?

A base material is the parent material to which a coating or plating is applied. The term base material helps to differentiate between the overall part, the various layers and the original base material. A base material is also known as a substrate.

What is a Type 1 Sub Base?

Type 1 Sub Base is generally a 40mm graded to dust material that is laid and compacted to form a level stable construction layer as a platform for asphalt or concrete. It is typically used in the construction of highways, car parks, footways and hard standing areas.

Can I use bricks as a sub base?

Recycled crushed brick and crushed concrete are viable substitute materials for natural construction materials in engineering applications such as pavement sub-base and other road construction applications.

What are the different types of sub bases?

Typical Sub-base Designs. 1 Sub-base Light Duty. (light, foot traffic only – paths and patios) 75mm compacted thickness of DTp1 or of 50mm crusher run, compacted with a vibrating 2 Sub-base Light-Medium Duty. 3 Sub-base Medium Duty. 4 Sub-base Medium-Heavy Duty.

What are the requirements for a good sub base?

The other key requirement for a well-constructed sub-base is that the surface, once compacted, should be “Tight”. Essentially, this means that the surface should not have too many (or any!) open voids, but should be a reasonably uniform and smooth-ish. This is usually achieved by ensuring there are adequate fines within the sub-base material.

What is the purpose of the sub base layer?

The sub-base layer is often the main load-bearing layer of a pavement. It is designed to evenly spread the load of the paving, and any traffic thereon, to the sub-grade below.

What kind of aggregates are used in sub bases?

Sub-bases using bound or ‘rigid’ materials, such as the aforementioned concrete and macadam or asphalt are used, particularly on larger civil and commercial projects, but this page looks exclusively at those unbound aggregates, particularly those classified within the DTp x range (803 to 807 in Ireland).