Choosing the right road sealing materials.
Road seals play a big role in Australia’s road infrastructure. The country has a humongous road system that covers large distances to connect cities. Unfortunately, not all roads are built in the same way. The roads need to be more robust in bigger regional areas with dense.
Although road sealing is essential, there are some less frequently used roads with minimal wear and tear. It is more practical to use cheaper materials that need less maintenance. Here’s a rundown of the most commonly used road seals in Australia.
Types of Road Sealing Materials
Sealed roads prevent road surface degradation and reduce the need for expensive and time-consuming road maintenance. It revitalises the surface and form a protective layer against oil, salt, and water. It is an excellent investment for roads already showing signs of ageing but still structurally viable.
1. Chipseal
Chipseal is also known as tar and chip. It’s one of the most commonly used treatments for pavement surfaces. Chipseal is a combination of asphalt overlays and aggregates such as crushed rocks, sand, or gravel. It’s relatively less expensive than asphalt concrete but not as durable.
Chip seal is made out of expanded shale, clay, or slate (ESCS) gives a practical surface treatment for road repair. It also improves durability and safety. ESCS has a higher surface area for emulsion bonding because of its network of unconnected voids. This enables the road to endure high-speed traffic and usual wear and tear. The surface treatment’s lifespan can extend up to 10 years.
2. Bitumen
Bitumen is a by-product of crude oil and an extremely adhesive form of petroleum. It’s usually used as a binder for aggregates in making asphalt during road construction. It also serves as a waterproofing material in bituminous membranes.
Although it has a semi-solid form and has high viscosity, it’s still hard to work with at room temperature. It’s normally warmed up to make it more fluid and simpler to use in road construction.
To enhance the pavement’s lifespan, the Institute of Public Works Engineering Australasia (IPWEA) recommended four types of sprayed prevention treatment using bitumen.
- Enrichment – This applies a mixture of proprietary additives and bitumen to bituminous surfacing to create a protective shield against oxidation. Enrichment treatments are normally not filled with sand.
- Rejuvenation – This is usually applied to local roads at a rate of 0.35 to 0.50 L/m2. The binders used are proprietary products and water-based. The first application must be applied before year 8 to preserve the current binder’s viscosity and elastic properties. It will also stop the ageing of the bitumen binder.
- Polymer modified mastic – This is made up of mineral fillers mixed with bituminous material. It improves surface texture and hinders aggregate loss. It also lowers the traffic noise experienced in residential areas.
- Microsurfacing – This prevents oxidation and ravelling. It also improves surface friction, rutting, and minor irregularities in filling.
3. Tarmac
Tarmac is a shortened term for tarmacadam. This road sealing material is composed of a mixture of crushed aggregate like molten tar and sand. It is usually applied hot and then permitted to cool down to make a sturdy and strong surface.
Because of the above characteristics, tarmac is considered the ideal road sealing material for driveways. Unfortunately, its use has declined over the years because of the rising popularity of innovative bituminous materials.
4. Asphalt
Asphalt, also known as asphalt concrete, is manufactured by drying, heating and mixing aggregate, sand, and bitumen to form a composite mix like tarmac.
A paving machine applies it on site as a solid form at a prescribed thickness relative to the intended use. Asphalt leads to a smoother and highly durable road surface compared to a bitumen-sealed road. It is utilised mainly for pavement waterproofing and highway repairs.
There are times when asphalt and bitumen are interchanged. However, bitumen is a primary component of asphalt.
5. Crumb rubber
Crumb rubber is utilised as a spray seal binder in the country since the 1970s. Contractors and producers are exploring its potential as a practical maintenance treatment.
Its special formulation makes it more stable and can withstand prolonged heating and transport. It can be moved for thousands of kilometres without showing signs of settlement or degradation issues.
The best part is that it’s environmentally friendly because it’s a product recycled from end-of-life tyres. This also lowers the need for importing costly polymers to modify bitumen.
Determining the right type of road sealing material
Deciding on the road sealing material depends on the road’s susceptibility to damage. Some factors to take into consideration include:
Usage
The amount of traffic significantly affects the sealed road’s lifespan. Questions like, “Do heavy vehicles pass through this road” and “Is it consistently being used?” must be factored in.
For example, those planning to surface or resurface car parks, driveways, or commercial areas need asphalt, not bitumen. Asphalt gives a flexible and durable surface for machinery, cars, and heavy vehicles.
Climate
The climate in Australia can be severe at some parts of the year. If the sealed road experiences high temperatures, resealing must be performed more frequently. The ideal time frame is 3 to 5 years. Therefore, the road sealing material to be used should be more resistant to wear and tear if maintenance can’t be done at regular intervals.
Contact Northern Highways Bitumen, the premier source of road sealing materials in Australia.
A road will always need preventive maintenance, no matter how well it was constructed. Not only will it be able to continue to provide safe and viable roads, but it will also maximise the road budget.
Do you need high-quality road sealing materials for your next road project? Our wide array of government, residential and commercial clients can attest to the excellent quality of our materials. Give us a call at 1300 858 751 or email your enquiries to sales@northernhighwaysbitumen.com.au.
