Crack Seal
Crack sealing is the most important first step in maintaining an asphalt pavement, but is often the most overlooked. All cracks in concrete or asphalt surfaces can rapidly turn into major hazards. Water seeps into the subsurface; it freezes, thaws, and refreezes causing the subsoil to expand and contract. Soon the area around the crack rapidly deteriorates and what could have been a small maintenance step has turned into a costly repair project. Sealing the cracks helps keep water away from the base material. This is critical in preventing future damage from vehicle traffic.
Of unsealed cracks, 75-80% developed additional cracks and potholes. Of sealed cracks, 1% developed additional cracks and potholes. –Utah DOT
Crack sealing retards deterioration and extends pavement life by at least 4 years. –Ontario Ministry of Transportation
Seal Coating
Seal coat is used to extend the service life and reduce maintenance costs of asphalt pavements. It protects such pavements from the destructive effects of water, sunlight, oxidation, fuels, and oils. In addition, seal coat provides a distinctive new looking surface that is skid resistant, long lasting and easy to clean.
Why Seal Coat:
· Seal Coating seals the asphalt pavement, preventing the oxidation and erosion of the top layer of asphalt. It protects the surface from the sun as well as chemical spills such as oil and fuel.
· Seal Coating provides an attractive smooth black surface that is ideal for sweeping, lowering the cleaning costs.
· Seal Coating costs pennies a square foot compared to dollars needed to repair or replace damaged asphalt.
According to the ASMA (Asphalt Seal Coat Manufacturers Association) :
· All new asphalt and slurry seal should be crack sealed and seal coated in approx. 12 months after install.
· Crack seal should be touched up every other year to seal cracks that have expanded or reopened.
· Seal coating should be redone every 3-4 years or as necessity dictates.
In Arizona you don’t want to wait more than 3 years to seal coat a new construction project. The sun oxidizes the asphalt leaving it gray and brittle. This will lead to cracking from the vehicle traffic because of the loss of elasticity. Seal coat only protects the good surfaces, it does not revitalize deteriorated asphalt.
For every $1 spent on pavement preservation maintenance programs, $4 to $10 was saved in rehabilitation. The earlier the preventive maintenance was applied, the lower the loss and higher the benefits. –Montana DOT
Rehabilitation or reconstruction costs up to 14 times as much as pavement preservation projects per lane mile over the life of the project. –Michigan DOT
