Asphalt

What materials are used in asphalt?

Asphalt is one of the most sustainable and durable paving solutions. Typically, asphalt is made of three materials—aggregates, filler, and binder. Now, aggregates are the processed mineral materials, like crushed rock, gravel, sand, and slags, among other recycled materials. The binder, on the other hand, is used to join or bind the aggregates together to create a consistent mixture. Typically, bitumen is the material that’s commonly used as an asphalt binder. 

Now, when you look at an asphalt pavement, you will notice that it has multiple layers. These layers include bound and unbound bituminous materials, which act as the base layer before the asphalt is poured on the top. 

Ingredients of an asphalt mixture

Typically an asphalt mixture has two ingredients, which are asphalt binder and aggregate. The asphalt binder is a liquid with high viscosity, a byproduct of crude oil. The binder acts as a glue, which binds the small rocks (aggregate) together, thus creating a strong and flexible end product, which we call asphalt. An asphalt mixture is typically composed of 95% aggregate and 5% asphalt binder. 

So, looking at the lower layer of your asphalt pavement, you will see that the aggregate particles are a bit larger and less angular. For the surface level, on the other hand, the particles become smaller and angular. 

At times, small aggregate particles, also known as fines, can be added to an asphalt mix. This helps to prolong the lifespan of the asphalt paved surface. Apart from the asphalt binder and aggregate, some asphalt manufacturers can add some chemicals to the asphalt mixture. Some of these chemicals, like hydrated lime and polymers, help to create a tighter bond and better flexibility. 

However, it’s important to note that the ingredients that go into an asphalt mixture do vary—this depends on the climate of the area where the asphalt is to be installed. If the asphalt is to be installed in an area with a warmer climate, it’s hardened to withstand the high temperatures. On the other hand, asphalt for cold climate areas is made softer. 

How is asphalt mixture made?

Asphalt mix is usually manufactured in an asphalt processing plant. During the manufacturing process, all the ingredients require precise measurement for them to suit the target project, as well as the climate of the area. Now, after this, the thick asphalt binder or cement is thinned for it to mix well with the aggregate and other materials. 

There are different methods used to thin the asphalt binder, which includes dilution by applying an emulsifier or solvent in the water or applying heat. However, it’s important to note that heating is the most common way of thinning the asphalt binder. 

Then the asphalt binder is then washed, dried, and heated. After that, both the asphalt binder and aggregate are heated to the desired temperature, blended in a pugmill or drum—these are two machines used to create a homogenous asphalt mixture. When making asphalt, choosing the right temperature for the whole process is essential. Manufacturers are required to adjust the temperature depending on the time needed to transport the asphalt mixture from the production plant to the site, the thickness of the asphalt binder needed to start the process, as well as the time needed to compact the asphalt once it’s been poured.

Choosing the right asphalt

The experts from Florida asphalt paving contractor, ABC Paving every asphalt paving project requires a different asphalt mix. Typically, asphalt is mixed to handle different loads, reduce splash, absorb noise, treat water runoff, or spray when it rains. Here is the different asphalt mix that you should know. 

Quiet asphalt

Noise pollution can be very disturbing. However, it’s possible to reduce road noise significantly—by around 50% when you use stone mix asphalt, also known as quiet asphalt. Using quiet asphalt is more practical and cheaper than installing noise barrier walls. This is more practical for roads built in residential areas, and homeowners must make adjustments to the noise. 

Porous asphalt

This type of asphalt mix allows water to drain from the surface, into a recharge layer, and then into the soil under the driveway. Typically, this kind of asphalt mix is used for parking lots, and it also helps to improve stormwater management, as well as improve groundwater quality. Just like other types of asphalt, porous asphalt is used in different circumstances and situations, and it’s also durable. 

Warm mix asphalt

This kind of asphalt mix is ideal for paving projects done during low temperatures.  Typically, a warm asphalt mix helps to save fuel, extend the paving season, as well reduce the emission of greenhouse gases. Besides, warm mix asphalt allows better paving compaction. 

Hot mix asphalt

This is the best option for asphalt driveways. This is because the design and construction features of hot mix asphalt are ideal for giving driveways the finished looks that compliment your home. Also, hot mix asphalt is strong and durable, can withstand freezing and thawing, it’s easy to repair, requires low maintenance, and it’s cheap to install.