Council uses a range of surfacing and renewal treatments depending on the condition of the road, the required service life, traffic demands, and the available maintenance budget. The four primary treatments are road rejuvenation, road rehabilitation, chip sealing, and asphalt renewal.

1. Road Rejuvenation

Road rejuvenation is a lower cost preventive maintenance treatment used on road surfaces that are beginning to age but remain structurally sound.

A rejuvenating liquid is sprayed onto the existing road surface to restore some of the binder's flexibility and waterproofing properties. This helps slow the ageing process, reduce water penetration and extend the useful life of the existing pavement.

Outcome: Rejuvenation can provide a significant extension to the service life of the existing surface, potentially delaying the need for more costly resurfacing or rehabilitation.

2. Chip Sealing

Chip sealing is a medium cost resurfacing treatment and is one of the principal methods used to renew sealed roads.
The process involves applying a layer of bitumen to the existing road surface, followed immediately by the application of graded sealing chip. The chip is then rolled into the bitumen to establish a strong bond.

The second coat is particularly important, as it provides the additional bitumen and aggregate coverage required to create an effective waterproof surface and protect the underlying pavement from moisture.

Outcome: Provides a durable new sealed surface at substantially lower cost than full renewal, making it suitable for widespread network maintenance where the underlying pavement remains structurally sound

3. Road Rehabilitation

Road rehabilitation is a high cost treatment used where deterioration has progressed beyond the surface and the underlying pavement has become structurally deficient. Unlike resurfacing, rehabilitation addresses the underlying pavement structure rather than simply replacing the surface.

The process generally involves removing the existing pavement, excavating failed areas, stabilising or strengthening the underlying pavement layers, and reconstructing the pavement before applying a new suface. The treatment is designed to address significant structural defects.

Road rehabilitation is generally targeted at roads where preventative maintenance treatments are no longer sufficient.

Outcome: Restores the structural strength and serviceability of the road and provides a substantially longer service life than surface treatments alone, extending the life of the rehabilitated pavement by 15 to 20 years depending on the treatment and site conditions.

4. Asphalt Renewal

Asphalt renewal is a high cost treatment generally reserved for locations where the road condition, traffic environment or operational requirements justify the additional investment.

Asphalt provides a smooth, durable and high quality finished surface and is particularly suited to areas with higher traffic volumes, intersections, industrial areas, urban environments or where a higher standard of surface performance is required.

Outcome: Provides a high quality, smooth and durable surface, but at a significantly greater cost than conventional chip sealing.

The overall approach is to match the treatment to the condition and function of the road. Applying a lower cost preventive treatment at the appropriate point in the pavement's life can delay more expensive resurfacing and rehabilitation work. Where deterioration has progressed into the pavement structure, rehabilitation may be required to restore the road's structural integrity. Higher cost treatments such as asphalt are targeted to locations where their additional performance and durability justify the investment.