Numerous options exist in today’s paving world for preserving and maintain asphalt. This wealth of options means that it has never been easier to get the most from your asphalt. Yet it also makes it harder for many people to decide on the best option for protecting their pavement.
If you would like to learn more about the techniques used to extend the lifespan of asphalt paving, read on. Here you will learn about one of the most effective means of maintaining asphalt: fog seals. Learn the nature of fog seal to better determine whether this method of preservation will suit your particular needs.
Fog seal consists of a diluted form of asphalt known as asphalt emulsion. Such an emulsion consists of two main ingredients: asphalt and water. Successfully blending these two ingredients together requires a third component known as either a surfactant or emulsifying agent.
The surfactant allows the asphalt and water to exist together in a suspension. Otherwise, the two ingredients would separate, much like oil and water. In some cases, additional ingredients known as rejuvenators may be added to a fog seal. Rejuvenators soften the existing asphalt binder, allowing the fog seal to more fully bond with the pavement.
Fog seal is a good choice for adding an extra layer of protection to an asphalt surface. This seal will not compensate for more serious problems, like asphalt that has experienced more than minor aggregate loss. Fog seal will also not work as a method for treating cracks or other structural issues —crack sealers must be used in such cases.
Fog seal should be considered a rejuvenating option, meant to offset the process of oxidation that happens as time goes on. Such oxidation causes the asphalt binder in the pavement to weaken and grow brittle. Eventually, the aggregate will start working loose. Fog seal prevents this through the addition of extra asphalt.
Fog seal also helps to fill in tiny spaces that form between aggregate particles as the asphalt binder ages and wears away. This ensures that the surface remains smooth. Fog seal also increases the pavement’s ability to resist water damage by reducing the amount of water that can pool up on the surface.
Not all fog seals will have the same composition. They differ mainly in terms of their dilution ratio — in other words, the relationship between the amounts of water and asphalt. Numerous factors must be taken into consideration when deciding on the appropriate emulsion to use. These factors include traffic patterns, general climate conditions, and the size of the aggregate used in the pavement.
In order to successfully do its job, a fog coat must be diluted enough to easily flow down into the gaps between aggregate particles. There the water will evaporate, leaving behind an asphalt that will help to bind the aggregate together more strongly. An excessively thick fog seal will end up sitting on top of the aggregate. This leads to two main problems.
First, the fog seal will be exposed to much more friction, which means the seal will wear away quickly and leave the aggregate as unprotected as it was to begin with. Secondly, by remaining on top of the aggregate, an overly thick fog seal will reduce the pavement’s traction. This can be dangerous on high-speed roadways, as the loss of traction will make cars more likely to skid or lose control.
Determining the ideal dilution of a fog seal requires proper knowledge and experience. For more information on how best to protect your asphalt with fog seal, please contact the pavement pros at J R Paving & Construction Co., Inc.