Preventing Asphalt Failure and Extending Pavement Life

1.  Sealing Prevents Water Infiltration under the Asphalt: The number one enemy of asphalt is water. Preventative Crack sealing creates an airtight, flexible seal. Stopping rain and runoff from seeping into the asphalt base and sub-base layers beneath which support the raod. If water reaches these foundation layers, it  degrades and softens the soil, leading to instability and the start of potholes and expansion of cracks.
2. Sealing Inhibits Freeze-Thaw Damage: In northern Arizona’s colder climates, water can be trapped inside the asphalt expands as ice when it freezes. This water to ice expansion exerts massive internal pressure, widening the crack and breaking the surrounding heat set asphalt bonds. By keeping water out, sealing eliminates the yearly cycle of water to ice expansion that turns small cracks into large potholes over a single winter. You can view this affect in our northern roads as you travel the upper part of the state.
3. Protecting/Sealing the Crack Protects Against Raveling: When cracks are left open, the edges of the asphalt begin to crumble and “ravel” away as high pressure force of tires pass over them and slowly cause the crack to widen. Sealing covers and binds the edges together, reinforcing the perimeter of the crack and keeping the aggregate (stones and sand) locked in place and avoid being battered by tire stikes.
4. Crack Sealing Minimizes Oxidation and Asphalt Hardening: Exposure to air and UV rays causes the underlying oils within asphalt to oxidize. This gives rise to pavement becoming brittle and prone to further cracking. Street Crack sealing limits the amount of surface area exposed to the elements. This keeps the surrounding asphalt more pliable and resilient against the weight of heavy traffic.
5. Prevents Subgrade Erosion: If water flows freely through cracks, it can eventually wash away the fine particles of the subgrade. This creates “voids” or empty pockets beneath the surface. Without a solid foundation to rest on, the asphalt surface will eventually cave in under the weight of a vehicle, resulting in a localized failure or sinkhole effect.
6. Enables Top-Down Maintenance: By sealing cracks early, municipalities can delay the need for expensive bottom-up repairs like full-depth reclamation or total repaving. This proactive approach keeps the Pavement Condition Index (PCI) high, allowing for simpler surface treatments (like slurry seals) rather than multimillion-dollar reconstruction projects.

Pro Tip: Crack sealing is most effective on active cracks that are between 1/8 inch and 1 inch wide. Anything larger usually requires a more intensive mastic or patch repair.