Spray Applied Polymer Surface Seals - TSP2

Lessons Learned
Fog Seal
Where to Use?
Pavements in good condition
• Preferred:
Good friction & surface texture
No visible damage
AC/HMA rheology – before becoming too
brittle; approaching critical “m” value
• Acceptable:
Slight raveling or loss of surface fines
Minor surface cracking
Avoid “Worst First” --- Think Preservation!
Emulsified sealers and rejuvenators are best used as preventive maintenance
treatments on pavements in good condition, but with surfaces that have begun the
aging process. They can be used on any asphalt pavement that has sufficient
permeability to allow emulsion infiltration, but traffic should be controlled until the
seals have fully cured and friction numbers are restored to acceptable levels.
Sanding generally improves early friction, as long as loose sand is removed before
full speed traffic is restored.
Fog seals should not be used when a pavement has poor surface texture, large
cracks, rutting, shoving, structural deficiencies or low friction numbers. The
Minnesota SR251 project included crack sealing of thermal cracks a few months
after the fog seal had been applied. When applied at the right time, the emulsified
seals generally exhibited fewer new cracks than control sections.
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