Polyguard NW-75 saves time & money on failed pavement sections
There is an alternative to the costly practice of removal and replacement of failed pavement sections prior to an asphalt overlay.
On this project, the facility owner, who had planned removal and replacement of pavement sections, heard that he could save a significant amount on the project cost by applying Polyguard NW-75 underseal to all joints and cracks. Not only was the project cost reduced, but the entire project was waterproofed. Water now cannot get through the joints and cracks of the concrete to the subbase.
Procedures for Applying NW-75 to Concrete Pavement
1. Clean the old pavement
On this project, debris was removed from all cracks and joints, and the entire pavement was blown clean
2. Fill holes with asphalt patching material
The pavement surface should be relatively smooth in preparation for application of the NW 75 Underseal and asphalt overlay
3. Equipment and supplies needed:
- Brooms for final cleaning
- Utility knives to cut underseal to size
- Liquid adhesive primer (not always needed - see 4) with sprayer
- Rubber tired roller (tractor or truce)
4. Spray liquid adhesive primer (if required) on joints and cracks in area where Polyguard is to be applied.
Primer is usually not necessary if temperature is >70 º F.
Apply a small test piece and walk on it; if it pulls off easily, primer is needed.
If temperature is between 40 - 70 º F, primer is recommended.
Primer should average 400 square feet per gallon when sprayed.
5. Roll out a roll of NW 75 along the joint
Once the roll is rolled out, center the NW 75 underseal across the joint.
6. Peel the first 6 – 12 inches of silicone coated release liner away from the adhesive face, and apply it to the pavement at the beginning of the joint
In this picture, Chris and Tony have peeled the release liner away and are ready to apply it to the pavement
7. With one crew member standing on the adhered portion, the other crew member should walk away down the length of the joint, pulling the release liner away as he goes
Crew should pause every 20 - 25 feet to make sure that the NW 75 underseal is still centered on the joint.
Note: For high volume projects, an installation cart is available.
8. Cracks in the slab should also be treated if they could allow penetration of water into the subbase
Hairline cracks do not need to be treated.
If multiple cracks exist, Polyguard NW 75 is available in wider widths (24" and 48") for easy area coverage.
9. After application, all NW 75 underseal should be rolled. A rubber tired roller is best.
The objective of this is to create 100% surface contact between the adhesive and the pavement.
