Bituminous or blacktop pavement by design is flexible to accommodate the freeze/thaw cycle of our climate. Subsequently, cracking will occur in relatively new pavement and continue throughout its life due to age, traffic, weather, etc.
Sealing cracks helps prevent moisture from infiltrating the pavement structure. This moisture weakens the structural subsurface layers and is the primary cause of pavement deterioration. It should be applied when temperatures are moderately cool, such as in the spring and fall.
Crack sealing is typically performed to streets:
- Selected for seal coating
- Follow-up maintenance to overlays typically two years of age
- First maintenance applied to new construction
Crack sealing is a three step process
The first step involves using a walk behind machine that routes or grinds the crack wider at the surface of the asphalt. This makes room for the asphalt polymer used in step three.
Cleaning a crack using a high pressure torch and drying any moisture in it. The crack must be clean and dry for the asphalt polymer to adhere to the crack.
The final step is filling the crack with a polymer asphalt filler that is heated to 350 degrees. Workers spread the filler over the crack and then spray it with a soap based sealer so that traffic can drive over the crack almost immediately.