There is no doubt that coming across roadway paving construction while on your daily commute can be frustrating. But, once the asphalt is laid in and the roadway is reopened, the commute becomes smooth, quiet, and free from those pesky potholes that ruin your tires and test your suspension system.
If there is a roadway being installed near you, you’re probably wondering how long it needs to settle or dry after paving? Typically, the answer is 24 hours, but if the weather is warm or humid, it could be closer to 48-72 hours or 2-3 days. Let’s take a look at the difference between curing and drying, as well as, what environmental factors lengthen the time between installation and when asphalt can bear traffic load.
What is the Difference Between Curing & Drying?
When you hear the term, “curing,” this refers to asphalt pavement hardening. This process can take up to 12-months to complete, but this does not mean that vehicles have to stay off the asphalt for this long.
As the asphalt begins to cure, the oils within the asphalt will evaporate due to the heat of the sun (oxidation), slowly changing the asphalt from a nice black to a lighter gray. This initial oxidation is a good thing as any excess oil in the asphalt can cause tearing, if the asphalt comes into contact with rough wheel turns or pointed objects like kickstands, or carjacks.
When it comes to drying, this simply means that the asphalt has cooled down enough to an ambient temperature. Once cooled down, the asphalt can be subjected to vehicle traffic without causing damage to the asphalt. The key here is that since the asphalt is not going to be cured for quite some time, things like antifreeze, gasoline, and transmission fluid spills can still cause problems, as can extremely heavy traffic loads (semi-trucks and buses).
What Environmental Factors Impact Drying Time?
While it normally takes about 24-hours, there are several weather-related factors that can impact drying time. These include the following:
- Humidity: if there is a lot of moisture in the air due to high-levels of humidity, the asphalt will take longer to dry as the air is less absorbent. If the humidity is over 90%, it is recommended to avoid sealing.
- Ambient & Surface Temperature: the air temperature (ambient), and the surface temperature of the asphalt have a direct impact on drying time. Essentially, the higher the temperature, the faster the oils will evaporate and thus create a quicker drying time.
- Sun: on a day when there is more cloud cover and less sunlight as a result, the drying time will take longer.
- Wind: if there is absolutely no wind, the air right above the surface of the asphalt will have more moisture in it, which leads to a longer drying time. If there is even a slight breeze, this will pull moisture away from the surface of the asphalt, enhancing evaporation and reducing drying time.
- Rain: while asphalt can get wet 24-72-hours after it is installed, anytime before then, and it will damage the asphalt installation process. This, in turn, will extend how long traffic needs to stay off the asphalt as the drying time is reset from the rain water.
Wrapping It Up
For asphalt roadways, the settling time needed is approximately 24-hours for most mix-types, but environmental conditions can lengthen that time up to 72-hours. After the initial 24-hours, most conventional automobile traffic can traverse the roadway as normal.