During the installation of an asphalt lot or driveway, the environment plays an important role in the time it takes for the pavement to harden and cool. This process, called "curing," can take six to twelve months, although it should be hard and dry enough to support traffic within a few days. In fact, resurfaced asphalt can accept foot and vehicle traffic within hours. Below is an introduction to what conditions asphalt needs to cure.

What Makes Up Asphalt?

Asphalt is composed of about one-part asphalt cement (a heated, sticky, black petroleum product) to about 19 parts aggregate (such as stone, sand, and gravel).

The curing process involves giving the mixture time to cool, dry, and harden enough to support the weight. The two most important factors in curing time are temperature and humidity.

What Are the Right Temperature Conditions?

Asphalt must cool slowly to achieve the proper density required to support heavy vehicles. Both the ambient temperature and the temperature of the ground must remain above 50 degrees Fahrenheit during the installation and for the next three days.

If it cools too quickly, the surface will become rough and prone to collecting water. Slab density suffers, and the pavement won’t last as long as it should.

Contractors pay close attention to weather forecasts when doing a paving project. In fact, stiff winds can carry away surface heat too quickly, so the ambient temperature may need to be above 50 degrees on windy days. 

What Are the Right Moisture Conditions?

Asphalt is petroleum-based, and rain on fresh concrete causes oil to rise to the surface, which can ruin the pavement. In fact, an important part of curing is the evaporation of moisture in the asphalt—and the more humid the air is, the less able it is to draw moisture from the cooling pavement.

The humidity level on paving day—and for the following 72 hours—should be under 90%, to allow the material to dry properly. If it’s too humid, it could take longer for it to dry enough to accept any weight. Moreover, rain during curing can cause cracks in the surface, and the sealcoating will not adhere to the asphalt’s surface when it is wet. 

If you need an asphalt driveway or parking lot paved, contact AAA Paving Company in Kernersville, NC. They specialize in both residential and commercial paving and have served Guilford County and the Piedmont Triad since 1989. Read what their clients have to say about them on their website or call (336) 723-1418 to schedule asphalt paving.