In spite of its excellent adhesive and waterproofing properties, asphalt has some serious drawbacks that relate to its chemical makeup. Asphalt is a very complex mixture of thousands of chemicals which provide easy access to weather, salts, and chemicals to attack and disintegrate the asphaltic molecules. As the asphaltic molecules disintegrate, the asphalt in the pavement loses much of its original properties, such as binding and waterproofing. The first visual sign of this phenomenon is a progressive change in the color of asphalt pavement from rich black to brown to gray.

Furthermore, other products that also are derived from petroleum – such as oils and fuels, fats, grease, mineral spirits etc – easily dissolve asphalt. Because these individual products come from the same source, they have a natural affinity for one another and when put in contact with each other will try to join together again. So, for example, when automotive oil or gasoline drops onto an asphalt pavement, they will work to easily dissolve the similar chemicals in asphalt.

Without proper maintenance (crack sealing, seal coating, etc.) eventually all the asphalt binder is exhausted and the aggregates begin to unravel. This happens to all pavement, including roads. The rate of pavement deterioration depends upon the traffic volume as well as climate conditions. The next step in deterioration is the development of minor cracks that widen and deepen with time. If these cracks are not repaired at this stage, water seeps into the base courses and damages the pavement’s load bearing capacity. Rutting, shifting, and serious alligatoring are evidence of this. The pavement then must be either overlaid or completely removed and reinstalled, depending on the condition.