Why Does Asphalt Turn Gray?

Asphalt pavement is formed by combining a tar known as bitumen with crushed rock, known as aggregate. The aggregate is what gives asphalt its structure, allowing for heavy loads. The bitumen is what holds the asphalt together and gives asphalt its color. Freshly paved asphalt is a thick, heat-absorbing black, but asphalt does not stay black forever. Over time, the bitumen can wear away and deteriorate, leaving gray aggregate—and therefore, gray pavement—behind.

Not only can this color change impact the aesthetics of your pavement, but asphalt that turns gray is also brittle and likely to crack. That is why it is important to maintain your asphalt pavement. You can trust A. Macchione Brothers to ensure your asphalt is properly installed and maintained.

Asphalt Wear and Tear from Traffic

One of the ways that asphalt can turn gray is through the general wear and tear of traffic. As vehicles traverse the road, they can wear away the bitumen in asphalt pavement, exposing the aggregate. On a small scale, such as in a personal driveway, this is less likely to be an issue, but on a grand scale, such as a road with heavy traffic, the stresses of vehicle travel can compound.

Asphalt Damage from Weather

Another potential cause of asphalt damage is weather. Freeze/thaw cycles, high heat, rain, and other weather conditions can all have an impact on the bitumen in asphalt. These changes in weather can alter the color of asphalt, but can also damage the structural integrity of asphalt. In winter, extreme low temperatures can cause asphalt to shrink, leading to potential cracks. In spring and fall, rainfall and snowmelt can cause water to seep into asphalt and slowly deteriorate the bitumen. In summer, asphalt is at the greatest risk of issues caused by sunlight and oxidization.

Asphalt Deterioration from Oxidization

Oxidization is a molecular process that occurs when asphalt is exposed to oxygen, and the process begins as soon as asphalt is laid. Asphalt that has faced oxidation for an extended period of time will become brittle, less elastic, and more prone to cracks and damage. Oxidation can also cause asphalt’s load-bearing capability to decrease.

Several factors impact the rate of oxidization, such as temperature, exposure to oxygen, and time, but asphalt can be protected from these factors. Being proactive about maintaining asphalt pavement can reduce the rate and effects of asphalt oxidation. Sealcoating is an excellent way to reduce the risk of oxidation, and should be performed every year or two before the asphalt oxidizes. After asphalt has oxidized, sealcoating will not be enough to repair the structural damage caused to the pavement.

Contact Us Today

At A. Macchione Brothers, we provide exceptional commercial asphalt paving services. We are a family-owned company, and we have gained an excellent reputation in the industry for our commitment and expertise. If you are looking for a team of professionals that understands your needs and can work with you to achieve your goals, we invite you to contact us to request an estimate.