What Is Granular Base Course?
What Is Granular Base Course?
A granular base course, also known as road base, is a mixture of crushed stone (or gravel) and sand which is used to provide a strong and durable foundation for a variety of civil engineering projects such as roads, driveways, pathways and more.
The composition of the material typically includes particles with a variety of sizes ranging from dust-sized particles up to 1.5 inches in diameter.
The combination of the various-sized particles allows a granular base course to compact well together, to provide an even surface for construction and increasing its resistance to erosion and weathering.
Its heat-tolerant qualities make it ideal for use in hot climates where other materials may deteriorate quickly due to excessive temperatures.
Granular Base Course is also oftentimes referred to as ABC or Aggregate Base Course material due to its primary components being aggregates.
What Is The Function Of Granular Base Course?
Granular base course is a layer of granular material installed directly below the pavement or asphalt surface.
Its primary function is to provide a uniform foundation on which the pavement can be built and stabilized so that it can resist external loads, such as traffic and weather conditions, without suffering any structural damage.
This also helps in ensuring a smooth ride for vehicles traveling over the pavement by preventing uneven settling of the ground beneath.
Granular base courses also help in providing permeability so that excess water is drained away from underlying soils to prevent softening and erosion, thus increasing durability and service life of roads.
What Is Difference Between GSB And WMM?
The primary difference between GSB (Granular Sub Base) and WMM (Wet Mix Macadam) in concrete is that GSB provides a load bearing capacity for roads, highways, paths, etc. while WMM provide a higher level of compaction than GSB and increased stability to the paved surface because of the binding properties.
In terms of composition, GSB typically comprises crushed gravel or stone whereas WMM typically consists of sand, cement and other aggregates with bitumen or tar as binders.
In addition, while GSB is laid directly below the pavement layer (called wearing course), WMM needs to be laid over the base course of GSB.
What Is WBM And GSB?
WBM (Water Bound Macadam) and GSB (Granular Sub-Base) are two important construction materials used in concrete works.
WBM is a layer of broken stones which is compacted and bound with water, gravels and sand, while GSB involves the laying of coarse granular material such as stone chippings and other aggregate particles to form a base layer before paving or concreting begins.
These materials act as a shock absorber against heavy traffic loads, provide improved level of surface drainage and stability, reduce reflective cracking due to temperature changes, thereby increasing the life of the finished pavement.
What Is Maximum Dry Density Of GSB?
The Maximum Dry Density of GSB (Granular Sub Base) is the maximum dry density of soil particles when they are subjected to compaction by a specific type of mechanical force.
This mechanical force applied in the form of vibratory rolling or static compaction, depending on the type of soil and its physical characteristics.
The higher the maximum dry density, the better the soil strength and stability for construction projects.
It is important to accurately determine this value beforehand so that an adequately compacted base layer can be constructed.