The City of Canning in Western Australia has developed a kerb overlay method for upgrading precast concrete kerbing which is cracked, out of alignment or of varying height. Compared to full replacement, this results in a 70 percent cost saving. Kerb overlay is particularly useful after asphalt resurfacing has reduced kerb height causing potential drainage problems.
Owning and operating its own slipform kerb machine, Canning had previously carried out kerb overlays where the new kerb completely surrounded the old. The old process required removal of reticulation and caused damage to grassed verges. All driveway sweeps and small radius bends had to be removed as the mould shape prevented a curved surface being overlaid.
A new mould has been developed with adjustable front and rear plates. The machine is now able to place a minimum of 40mm of concrete over the old kerb, or alternatively provide a minimum kerb height of 135mm above the road.
The machine refaces existing kerbs without the need to remove material from behind the old kerb, or sweeps at crossovers or intersections. There is no need to straighten old kerbing. As the concrete is vibrated into place, a strong bond is provided between the old and new kerbing.
Benefits for Council include the following.
- Time savings significantly reducing costs.
- No damage to verges and roads or requirement for road closures.
- Removal of old kerbing to landfill is not necessary resulting in reduced tipping fees and more landfill space.
The system achieves cost savings, while maintaining existing aesthetic values and alleviating flooding problems, all with minimum disruption.
For further information contact Ross Moody, telephone (09) 231 0606.
