Answer: When the surface of a road gets old the bitumen becomes brittle and cracks. Cracks allow water to get in under the road and undermine the surface leading to potholes and damaging the expensive pavement below the surface. Most resurfacing is preventative to stop water damage before it occurs so as to avoid the cost of extensive repairs to the pavement.
Answer: Council has an annual program of road re-surfacing. The amount of work done is determined to manage the surface and pavement condition to reserve the pavement assets in the most effective manner across the whole shire. There are many surfacing treatments available, the two most common types of surfacing performed are:
• Asphalt, a bitumen-based concrete-like mixture of stone and bitumen laid at 30mm thickness or greater.
• Sprayed seals, a film of bitumen sprayed on the road and covered with aggregate.
Treatments are selected depending on the condition of the existing pavement, the road function and the traffic volumes.
Answer: Bitumen based treatments are also known as flexible pavements because they can move and spring back under stress without cracking. This is essential to prevent traffic (fatigue) damage, to prevent water undermining the road pavement and provide a long road life. Bitumen surfaces are fully recyclable and repairable and therefore more economical to maintain.
Approximately 90 per cent of Australia’s sealed road network area is surfaced with sprayed seals, with the majority of the remainder being asphalt.
Why are some areas treated with asphalt and others with spray seal?
Answer: Where there is the presence of heavy vehicles or areas of high stress on the road pavement such as in intersections; asphalt may be used as the resurfacing treatment. Asphalt treatments are expensive and only used where spray seal treatment may not be suitable. The most effective resurfacing treatment has been selected for your street to preserve the Shire’s pavement asset.
Answer: Your street has probably been spray sealed. This requires coverage of aggregate to be laid over a film of bitumen, to provide a hard wearing, skid resistant surface. In order to ensure all of the bitumen is covered, a little more aggregate is placed than may actually stick to the surface. This aggregate is left on the surface for up to seven (7) days before being swept off. The loose aggregate gets moved around during this time because of traffic and may collect on the road or in gutters giving the appearance of being heaps of aggregate.
This aggregate is then removed and is recycled. Residents should be mindful of any loose aggregate and that it is only a temporary issue until such time as it is swept from the roadway.
Answer: Streets that have been spray sealed before will normally be re-surfaced with another sprayed seal. The original seal may have become worn and the aggregate may have become polished by traffic, giving the appearance of a smoother road. Resealing renews the texture in the road that would have been there originally. The new seal will also get smoother over time.
Answer: The film of bitumen sprayed during the sprayed sealing process needs to cure after the aggregate is spread and rolled. During warm weather a new spray seal is susceptible to scuffing. Scuffing occurs when vehicles back out from driveways and turn the power steering whilst stationary. If this occurs on warm days, the aggregate under the car tyres can turn over in its place, exposing a thin film of bitumen on top of the aggregate. This can be avoided by not turning the steering wheel while the car is stationery.
The bitumen film and loose aggregate can be sticky on warm days, please avoid contact with shoes as it can track into your home and/or vehicle. Scuffmarks are not normally damaging to the seal and they are not a defect in the seal, they are an unwelcome but expected result of modern traffic movements on this type of surface. These marks become less frequent as the bitumen cures and they will eventually stop occurring.
Answer: On some of the Shire’s Roads the surface colour of an existing road may change. The colour change generally relates to a change from a light brown colour (Granitic Surface) to a black colour (Basaltic Surface). This will sometimes occur when traffic conditions have changed in your street or when vehicular movements will affect the longevity of the newly sealed surface.
This “Basaltic” treatment will tend to be used on roads with high traffic volumes, roads which are narrow, roads that have court bowls or hammerheads, roads that are steep or on roads which intersect with this similar colour. These basaltic road surfaces are of higher quality and are more resistant to damage and everyday wear and tear.
Answer: The cost of maintenance works such as these are based on time to complete the works. Allowing our contractors full and unhindered access to your street will ensure their time is used efficiently and that cost and inconvenience is reduced to a minimum. This type of work occurs only once every twenty years or so and are necessary to maintain the local road network for the benefits of all residents and road users.