03/12/2014
A good asphalt pavement will not last forever; external factors destroy the asphalt oil that binds it all together. Slowly at first, quickly as time goes on.
As soon as the freshly laid hot asphalt pavement mix begins to cool, so also begins the aging process which will eventually rob the pavement of its life. When oxygen and water, which constantly bathe the pavement, start to combine with the asphaltic binder of the pavement, a chemical change takes place. At first, this process is necessary for the pavement to become hard and firm. Later, if this process is not arrested, a complete deterioration of the asphaltic binder will take place and reduce the pavement to a layer of loose stone. The asphalt binder is essentially what differentiates a gravel road from a paved road.