Discussing Paving Contractor Services

2 Common Causes Of Damaged Asphalt

Asphalt is a much more fragile paving material than many people realize. Unless properly taken care of, it is liable to become damaged and decayed long before it should. Whether you have recently installed a new asphalt surface, or are simply interested in learning more about prolonging your current one, read on. This article will introduce you to two common causes of damaged asphalt--and how to circumvent them.

The Sun

Asphalt is particularly vulnerable to becoming damaged over time by the oxidizing effects of sunlight. This problem is specifically tied to the presence of ultraviolet rays in the light of the sun. These rays cause the binding oil that holds the asphalt together to break down and become brittle. As a result, the stone aggregate tends to crumble and come loose, forming potholes, cracks, and other unsightly problems.

Luckily, the long term negative effects of sunlight can be mitigated to a large degree by applying sealcoat every few years. Sealcoat is the name for a type of emulsified asphalt. In other words, it consists of asphalt that has been diluted through the addition of water and other hydrocarbons. It is sprayed evenly across the asphalt surface.

As the water in the seal coat evaporates, the asphalt is left behind to seep into the surface of the pavement. This helps to refresh the asphalt's oils, thus increasing its resistance to the harsh light of sun. Regular sealcoating can extend the lifespan of an asphalt surface from approximately ten to as much as thirty years.

Large Vehicles

The weight of large vehicles--whether garbage trucks, delivery vans, or semis--can cause serious problems for asphalt. As you can imagine, the reason for that is the fact that such vehicles weigh substantially more than your average four door sedan. The important factor here is a measure of force known as the equivalent single axle load, or ESAL for short.

Trucks and other vehicles with a high ESAL bear down on the paving surface with a much greater force. This tends to compress the asphalt. Over time it will cause cracks, ruts, and potholes, as the asphalt deforms under the excessive load. Luckily, certain types of asphalt do a better job of withstanding high ESALs.

So-called stone matrix asphalt is especially designed so as to provide a greater degree of resistance to damage caused by heavy loads. This effect is achieved by omitting medium sized aggregate particles. A greater degree of contact between large aggregate increases the overall stiffness of the surface. Go here for more about this topic.