These elements break down the oils and cohesive properties in the asphalt.
As new asphalt ages, the small open cracks are formed between the asphalt from oxidation and rain. These small cracks permit water, salt, fuel, oil and ultraviolet rays to penetrate into the base, leading to greater damage unless repaired properly. Water is said to be the most damaging agent to asphalt. This leads to larger cracks, eventually collapsing into the eroded voids, causing potholes.