Seal coating and crack filling play special roles in the longevity of pavement. Just as we use caulking and painting to repair certain components of a structure, asphalt surfaces have to have the same type of attention and seal coating and crack filling is the way that that happens.
Seal coating has what is called “barrier properties.” Through time, the sun causes asphalt to harden and that means the functional properties break down through oxidation. When the asphalt hardens, it becomes brittle and this can cause it to crack. Seal coating shields asphalt from the harmful effects of oxidation that is caused by the sun. If asphalt is flexible, it can react to the changes in temperature and this can cause the asphalt to be affected by heavy loads due to expansion and contraction.
And naturally, there are a number of voids in asphalt since it is made of sand and tar. Some of the voids are there during the initial paving and others develop over time due to the traffic flow and oxidation. Seal coating helps fill the voids, which reduces or even eliminates water penetration into the first ¼ inch of the surface. When water moves across a voided surface, friction is created and friction is an enemy of asphalt. Over time, this friction will cause the asphalt surface to develop a point of failure. If pavement sealer is used, then this is something that won’t happen.
Barrier Properties of Seal Coating
Another barrier property of seal coating is that it is the first line of defense against chemicals that vehicles tend to leak out onto the asphalt. These chemicals include oil, antifreeze, and gas. Any kind of petroleum-type product will cause the asphalt to break down in the same way paint thinner breaks down an oil-based paint.
The crack filling gives the asphalt barrier protection by treating the cracks that have developed. The crack filling is a rubberized filler that will expand and contract accordingly, remaining intact for quite a while. However, the crack has to be properly prepared before the crack filler can even adhere to the old asphalt.
If the cracks are not random and they are causing the pavement to fail, patching and more in-depth repairs may be needed.
But while crack filling is done on all types of asphalt, seal coating is not ideal for roadways where vehicles travel at high speeds. Seal coating is more appropriate for:
Parking lots
Residential roadways
Airports
Bicycle paths, trailways, greenways, and golf cart paths
Outdoor basketball courts, tennis courts, and other paved surfaces used for recreation
Advantages of Seal Coating and Crack Filling
The main benefit of crack filling and seal coating is that it is your first defense against the deterioration of your pavement. The seal that it creates prevents water from damaging the sub-base of the asphalt. You also receive better uniformity of the asphalt.
Another benefit is that crack filling will preserve the pavement that is next to the cracks, preventing stone, sand, and dirt from entering the cracks and causing compressive stresses. Crack expansion is minimized a great deal.
Proper Maintenance
Proper maintenance of asphalt can significantly increase the life of the asphalt, not to mention the asphalt will be more aesthetically pleasing when it has a barrier membrane surface that is like new. This is a way in which you can protect your investment, thus save yourself money. You would be amazed at the difference in cost between replacing asphalt and simply having it repaired. The difference is quite significant.
By giving asphalt cracks the proper attention, the spread of problems can be prevented. Pavement that is repaired in the first stages of deterioration will delay expensive resurfacing. It is good to walk along the pavement from time-to-time to identify cracks so they can be immediately addressed.
There is also the fact that repairing asphalt results in less downtime than replacing it. Pavement sealer can be applied in sections, allowing the remainder of the pavement to be used. So when you see cracks or the breakdown of asphalt, having it maintained will solidify its longevity so you do not have to replace the asphalt prematurely. Your bottom line will benefit a great deal.