Sub-base supply in Chinchilla and Queensland
What is sub-base?
In highway engineering and pavement construction, there are typically six layers which go into forming the pavement surface.
- Fine-grained Sand
- Pavers
- Paver Base
- Base Course
- Sub Base
- Subgrade
Sub-base is an aggregate layer that is located between the subgrade and base course layers and will be made of either unbound granular or cement-bound materials. The sub-base layer is often considered one of the most important, typically acting as the main load-bearing layer of the pavement structure, which disperses the pavement load onto the subgrade layer below.
While cement bound or unbound granular sub-base is often selectively used on pavements designed exclusively for foot traffic, it is a necessary component for any surface used by vehicles or any other load-bearing objects where load-carrying capacity is a crucial element of the construction process.
When it comes to sub-base, the quality of materials is vital to the project, given the effects it has on the useful life of the finished pavement. A good quality sub-base will often outlive the pavement’s surface, meaning once scraped off and the sub-base is examined, a new surface layer can be applied without actually replacing the sub-base.
What are the different types of sub-base?
While sub-base has the same application across most residential and commercial projects , not all sub-bases are equal. There are many different types of materials used to construct a sub-base which are dependent on the inherent load-dispersion and drainage capabilities needed. Typically there are two types of material:
Unbound granular base material
Unbound granular materials are aggregates that aren't bonded or adhered when laid and compacted, but rather remain loose. This form of sub base relies heavily on the natural conforment of materials and can be loosened and removed with ease.
When discussing unbound granular material you will commonly hear about different classifications, all suitable for different projects. The classifications of these materials are:
- DTp Type 1
- DTp Type 2
- DTp Type 3
Cement bound material
Cement bound material is also commonly referred to as a hydraulically bound sub base. These materials are bonded together through a binder, usually made of bitumen or cement and are consequently more difficult to remove or loosen when compared to its unbound granular counterpart. Their hydraulic conductivity also makes for a significant reduction in water infiltration, allowing these materials to serve effectively in pavement sub-bases. There are typically three classes of cement bound material including:
- CBGM A
- CBGM B
- CBGM C
What sub-base to use?
Some of the most commonly asked questions we receive are about sub-base base and, more importantly, which sub-base to use. From “What sub-base for a driveway?”, “What sub-base for a patio?”, to “What sub-base is best suited for roads?” We have heard it all. While the sub-base can be generalised, it is best to seek professional assistance or advice with any project you are unsure about.
Typically across smaller-scale projects, including patios and driveways, an unbound granular material can be utilised, however, when undertaking commercial or large-scale developments, cement-bound sub-base should be used.
If you are unsure which type or classification of sub-base you require, be sure to contact a professional. You can contact our quarry supply professionals on 1300 291 130.
Sub-base supply service areas
As one of Australia's leading sub-base suppliers, you can always be sure you're getting the absolute best in quality and customer service when you work with the team at Boodle's Concrete. After more than 50 years in the construction and earthwork industries, we know the importance of relationships in every aspect of our business. That experience also means we can share our relationship with you, and bring the absolute best materials to your next project.
Boodle’s Concrete services can supply sub-base all over Queensland. We are based in Chinchilla but can supply the surrounding areas, including Brisbane, Toowoomba, Sunshine Coast, Gold Coast, Biddenden, Gayndah, Miles, Roma, Charleville, Biloela, Emerald, Rockhampton, Gladstone and Bundaberg.
To find out more about our quarry rock and product services or to place an order for a sub-base or our other quarry supplies, contact us directly on 1300 291 130.