Curing of asphalt is an essential step in constructing or repairing roads. If an asphalt mixture is not adequately cured, the material’s strength and other physical characteristics will be compromised. Additionally, the curing time of asphalt has to do with mixing proportions, climatic conditions, and application practice. Here in this article, we will outline how long asphalt takes to cure and the influencing factors.
Curing of asphalt involves changes in the mixture’s components that are rendered by heat and pressure. This process is essential in improving the standard binding qualities and strength of asphalt. The curing process starts as soon as the asphalt is applied on the road and could go on for some weeks or even months.
What Influences the Curing of Asphalt?
The time required for curing asphalt varies with the help of a few factors.
Some of these factors include:
Mix Design
The time taken to cure asphalt mostly depends on the mix design adopted for the Pavement project. When designing the mix, it is important to ensure that the ratio of the aggregate, binder, and filler are ideal so that the curing process of the mix will be easily predicted. It should be noted that the curing time depends on the type of asphalt binder. For instance, polymer-modified binders tend to cure longer than the ordinary binders used in construction.
Weather Conditions
Weather factors that influence the curing of asphalt include temperature and humidity. High temperature increases the reaction rate of the asphalt’s chemical system, hence improving curing. On the other hand, lower temperatures lead to a longer cure time because asphalt will cure at a slower rate. In addition, high moisture affects the drying time, thus increasing the curing time.
Application Methods
The method used to put down the asphalt can also affect the curing time of the surface. For instance, shaving a small amount of asphalt would take a shorter time to cure than shaving a thicker layer. Further, the roller can be used on the asphalt paving after laying to help it cure faster.
Traffic Load
After the asphalt has cooled down and the curing of the layer has begun, it is affected by traffic load. The asphalt curing process can be hastened where there is heavy traffic or slower if there is light traffic on the pavement.
Curing Time for Asphalt
Curing of Asphalt takes time and depends on one or more of the following:
The initial curing time can take anywhere from 24 hours to days as the asphalt begins the natural curing process. This is normal, and as the curing process occurs, the surface of the asphalt will seem soft to the touch, almost sticky.
This period of time to completely cure may take a few weeks or as much as several months in total, depending on certain conditions. While the pavement is curing, it essentially means that it is hardening and thus, acquires more strength and density, and ultimately is able to endure more of a load and for a longer period of time.
Short-term Curing
Ninety percent of the strength of asphalt is acquired during the time in which it is curing in the first few weeks; this is what guarantees that it will be able to support regular traffic.
Long-term Curing
Long-term curing may last for several months to even longer, depending on the impact of adverse weather factors or other mix designs. It will also mark the stage after which the asphalt gains its strength and achieves its desired characteristics long term.
Proper Curing is Essential
Curing of asphalt plays an essential role in the performance, strength, and durability of the created material. When the surface has been sufficiently cured, it is more resistant to cracking, more resistant to forming potholes, or any other signs of deterioration. It also provides better skid resistance than prior to curing, and it makes driving easier for motorists.