If you have asphalt paving in San Antonio, TX, you may have heard the term sealcoating before. But you're probably not sure what it means or if it is even essential. Simply stated, a sealcoat is a mixture of small particle solids, like grains of sand, mixed with special liquids that combine to protect and restore asphalt pavements. Sealcoating is usually made up of various amounts of mineral fillers, dissolved asphalt, and water. It is typically applied as a spray or spread onto an existing asphalt surface with a squeegee or broom. Sealant is expertly engineered using materials and oils commonly used in asphalt paving services.
When applied to the surface of asphalt pavement, the oils in the sealcoat seep down into the existing asphalt surface and help to replenish the depleted asphalt oils and binder that have dried up over time. The tiny sand asphalt and mineral particles fill in gaps and small cracks between the pieces of aggregate, evening out and leveling the surface. The existing asphalt pavement surface usually looks nearly new with the oils replenished and the cracks and gaps filled in. Sealcoatiing also acts as a protective barrier between the existing asphalt pavement and harmful elements like UV rays from the sun, chemicals, water, and abrasion from traffic.
Asphalt consists of 95% aggregate, which is small gravel and sand particles. At the same time, the other five percent is asphalt or bitumen, the sticky, oily black substance that binds the pieces of gravel and sand particles together. Asphalt oils are fresh and pliable, making pavement flexible when it is new. However, the oil dries up or oxidizes over time, making asphalt less flexible and more brittle. In addition, the reduced amount of asphalt binder can cause the tiny gravel particles on the surface to be exposed and work their way loose from the pavement. This is known as raveling. Applying a sealcoat helps reintroduce oils and restores the pavement's original flexibility. Seal coat also covers and protects exposed aggregate to help prevent raveling.
Although sealcoating is not designed to repair damaged asphalt surfaces, it can seal up minute cracks in pavement surfaces. More extensive damage requires repairs on the existing asphalt before the sealcoating process can begin to ensure a long-lasting, quality finished product. Sealcoating can also help to keep those minute cracks from expanding and causing future pavement damage.
Preserving asphalt pavement with a sealcoat is one of the most cost-effective maintenance projects that you can do. Sealcoating costs an average of 20 cents per square foot, while new asphalt paving averages about two dollars and twenty-five cents. Regularly maintaining asphalt pavement with sealcoating helps it last about 30 years, saving property owners thousands of dollars.