What is joint sealing?
Joint sealing is where we seal the joints in concrete pavements.
Why do we seal joints?
Joint Sealing is done to prevent the ingress of surface water, below the concrete slabs, into the substructure of the pavement.
Water infiltration is “the beginning of the end” for pavement.
Water that penetrates to the sub base of the pavement will allow it to soften and become unstable. Joint Sealing of a concrete slab also prevents the joints filling with non compressible matter, which will prevent expansion joints from allowing movement, thus shifting stresses to other points in the slab which eventually leads to irregular cracking.
Unsealed joints may allow a concrete slab to sink and crack.
If utilized early enough, joint sealing can defer, and even eliminate the need for more expensive maintenance; such as Slab Jacking or Stabilizing (Mud Jacking, Lifting or Pressure Grouting), or in the worst case, the costly complete reconstruction of the concrete slabs.
The use of joint sealing on a concrete pavement prior to an asphalt overlay slows and greatly reduces reflective cracking on the new pavement layer.
What type of joints are suitable for sealing?
Longitudinal joints (construction, control, or expansion joints).
Transverse joints (construction, control, or expansion joints).
Joints must always be dry.
Depending on; the type of joint, desired service life, serviceability, and budget, joint preparation may involve any combination of the following:
- Weed Poisoning
- Raking or Ripping
- Power Routing
- Blowing Out (with compressed air)
Excessively deep joints may also be packed with backing rod prior to sealing.
As a minimum, joints are always blown with compressed air to clean the joint of loose material, which may prevent bonding of the sealant.
What type, of materials are suitable for joint sealing?
For the best performance and cost effectiveness, a hot applied rubber modified bitumen sealant will always yield the best results.
All Concrete Pavement Management Systems should include a suitable joint sealing program. This allows greater utilization of your pavement maintenance budget.
Joint Sealing works effectively as both a preventive and routine maintenance.
With an effective joint sealing regime you will be able to prevent water from deteriorating your pavement sub-bases and prevent the need for more expensive Slab Jacking, Stabilizing (Mud Jacking, Lifting or Pressure Grouting) and reconstruction.