Extending Road Life
Keeping roads in good condition for as long as possible – that's the goal of the City of Kingston's road-network maintenance activities. The City is always looking for opportunities to implement new technologies and construction techniques to help us keep Kingston roads in good shape. Here are a few of the ways we are working to improve Kingston roadways:
Microsurfacing – a sustainable way to extend road life
Where possible, a method called microsurfacing is used to extend the life of the asphalt. (A sound pavement structure needs to be in place for microsurfacing to be viable.)
Microsurfacing is a cost-effective way to preserve pavement used by City contractors. It involves applying:
- A seal coat of asphalt emulsion (basically, asphalt and water) and construction aggregate (sand, gravel, crushed stone and particulate). This layer fills minor wheel ruts.
- A final microsurfacing mixture of asphalt emulsion, fine-crushed stone aggregate and water to further protect the road's surface.
Each treatment is applied in a thin layer designed to seal the pavement and prevent water from getting down into the road base to reduce deterioration, extend the life of the road and create a surface that offers a coarser texture for better skid resistance and a safe-wearing surface good for up to eight years.
Microsurfacing costs three to five times less than traditional applications. In addition to cost savings, it is more environmentally-friendly, uses fewer materials and can be completed much more quickly – reducing the impact of construction on traffic.
TRAK Technology – increasing asphalt impermeability
The City is testing a new asphalt-compaction technology on the Front Road Bridge called TRAK. The asphalt compaction technology was developed by Carleton University Professor Abd El Halim.
When you think about compacting asphalt, you might picture a steamroller. TRAK is a new compaction technology that replaces the standard three-roller compaction method with a single, static compaction machine. This single machine can make the asphalt up to three times more impermeable than the standard compaction process. Greater impermeability leads to a longer service life for the road – and increases skid resistance on the road when it's wet.
The north side of Front Road Bridge has been paved using a standard compaction method and the south side using TRAK. The bridge is being monitored by the City's engineering department to compare the TRAK system with standard paving methods.
FiberMat Technology – slowing the appearance of cracks
FiberMat can slow the appearance of surface cracking by five to seven years.
FibreMat involves placing chopped fibreglass strands between layers of asphalt emulsion to slow the appearance of cracks in roads and extend the life of road surfaces.
FiberMat is applied to a road surface in layers using special paving equipment. First, a layer consisting of asphalt, water and construction aggregate – material like sand, gravel and crushed stone– is sprayed on the existing road surface. Chopped fibreglass strands are then sprayed onto the asphalt mix, followed by a second layer of asphalt mix to seal the surface and ensure the fibreglass strands are protected. Gravel is then rolled into the surface for added strength. A final surface layer of asphalt will be added over FiberMat layers later to provide a smooth and safe driving surface for vehicles.
FiberMat acts as a waterproof layer to help prevent water from getting into the road base and slows the appearance of cracks in the surface of the road. It also slows the appearance of cracks by better absorbing the strain of vehicle loads than traditional pavement. Benefits to the FiberMat process include its fast application, which allows road surfaces to re-open to traffic more quickly. By extending the life of existing road surfaces, FiberMat also uses fewer materials and less energy than traditional paving methods and is also more cost-effective over its entire lifecycle when compared to the costs of traditional paving techniques.