Asphalt pavements have two major weaknesses that lead to this limited lifetime.

 

1. The first asphalt has poor resistance to UV radiation or simply sunlight.

 

Asphalt pavements are a simple combination of rock, sand, and glue, which is the liquid asphalt that binds everything together. The UV radiation breaks down the asphalt glue and weakens so that it can no longer hold the rocks and sand, thereby gradually losing the top surface.

 

The first and most obvious sign of this degradation is the gradual change in the color of the asphalt from black to brown and finally to gray.

 

Next, your parking lot begins to look rough and piles of sand seem to appear in the low areas of the parking lot. This is not from your neighbor’s yard but the deterioration of your parking lot.

 

In the later stages of degradation, the bigger rocks fallout, raveling takes place, and the parking lot is rough, extremely dirty because now dirt and grass fill the spaces where rocks were.

 

Also because the asphalt is oxidizing under the UV radiation, it loses its flexibility. This flexibility is extremely important because asphalt can take great loads and bounce back to its original condition. As asphalt loses its flexibility, it becomes brittle and begins to crack and break.

 

2. The second major weakness of asphalt pavements is its poor resistance to salts, chemicals, and petroleum products.

 

Petroleum products cause most of the damage as witnessed by oil spots and gas spills. The reason for its poor resistance is that asphalt is a petroleum product. They are separated only by the refining process of crude petroleum. Naturally, gasoline and oils will dissolve directly into the asphalt, soften the structure, and eventually cause major damage to asphalt pavements.

 

Based on these two weaknesses: poor resistance to UV radiation and chemicals such as melting salts and petroleum products, it is logical to conclude that one should use some sort of coating that would shield the asphalt pavements from these harmful elements that lead to the degradation of your costly asphalt parking lot. This is, in essence, the idea behind seal coating.

 

After much of the deterioration just described occurs this, unfortunately, seems to be the time when many people call the seal coater and want them to make everything better. Well, we can do a lot and make it look black, but much of this deterioration could have been avoided with regular preventative maintenance.

 

Asphalt surfaces can be effectively protected by using a seal coating, which acts as a barrier between the external harmful elements and the asphalt pavement. Usually, a coal tar emulsion sealer is used, which is highly resistant to water, gas and oil, salt, chemicals, and UV radiation. It is the perfect substance to combat the degradation of your asphalt pavement.

 

Before seal coating, the asphalt must be cleaned to be free of all dirt, vegetation, and other foreign debris using blowers, sweepers, brooms, and sometimes high-pressure washers. Once the pavement is cleaned then any existing oil spots should be primed so that the sealer will adhere. Normally, two coats of sealer are applied to the asphalt sealer either by squeegee or spray. Once the seal coating is completed, it is very important to give adequate cure time for the coating, which is to keep traffic from the freshly sealed surface for 24 hours. Traffic before 24 hours will cause premature wear and increased tire marking. During this 24-cure period, the striping can be accomplished so that after the 24 hours, your parking lot is completely ready for traffic.