Asphalt does not last forever. If you own an asphalt driveway or parking lot that fact may be something you want to think about from time to time. Asphalt surfaces are made up of sand, gravel and an asphalt or bitumen binder which is the glue that holds everything together. Asphalt surfaces break down because of two main reasons. Sun and water damage. Ultra violet rays from the sun oxidize the petroleum based asphalt binder causing it to lighten up and significantly weaken. Once the asphalt glue is weakened it will begin to lose strength, leading to cracks and potholes. The driveway is now deteriorating faster every season that goes by. As the stones begin to unravel potholes can appear. Cracks appear leading to water infiltration. Water infiltration during warm months can undermine your driveway leading to depressions and more cracks. In the cold months that water freezes and heaves apart your driveway.
Applying seal coat to an asphalt surface is very important for maximizing the longevity of the pavement. A newly paved surface should be seal coated when it begins to lighten in color. Usually 1-3 years after it has been installed. A surface which has been crack sealed because of deterioration should have a coating of sealer applied to it to protect any repairs and rejuvenate the asphalt which is not yet cracked.
How does the sealer help the asphalt surface? The sea lcoat is comprised of solids such as sand or pulverized slate and liquids such as coal tar or asphalt emulsion. When the solids and the liquid binders are mixed and applied to the driveway, they fill in where the original binder has worn away. The solids add traction and provide added strength and durability to the liquid as it hardens and cures to a beautiful black finish.