How is Asphalt Made? A Look Inside the Manufacturing Process

How is Asphalt Made? A Look Inside the Manufacturing Process

How is Asphalt Made? A Look Inside the Manufacturing Process

Asphalt is a staple in the paving industry. But how is asphalt made? Learn more about the manufacturing process of asphalt here.

Keyword(s): how is asphalt made

Asphalt is everywhere.

It's in the roads we drive on, the sidewalks we cross, and even the airport runways we land on.

In fact, around 18 billion tonnes of asphalt is plastered around the United States alone.

But have you ever thought to yourself, "How is asphalt made?"

Well, wonder no more. Read on to find out.

The History of Asphalt

Asphalt dates back as far as 2,600 B.C when the Egyptians used the composite material to waterproof their mummies. Other ancient civilizations adapted it for highways and irrigation systems.

These days, it adorns almost 94% of American roads.

What Is Asphalt Made Of?

Asphalt composition is around 5% asphalt cement and 95% aggregate.

Asphalt cement is a type of liquid petroleum that works as a glue to bind the aggregate together.

Aggregate varies depending on climate and other requirements. Essentially, you could define it as a bunch of small rocks.

On the lower sections of a pavement, the aggregate comprises of larger and smoother rocks. At the surface level, however, the aggregate is finer and more course.

Other additives may be included to improve the final product. For example, hydrated lime can help bond the aggregate, polymers can enhance flexibility, and tiny particles known as "fines" can extend the lifespan of the pavement.

How Is Asphalt Made?

Manufacturers create asphalt in a plant, of which there are some 3,500 in the United States.

Manufacturers create an aggregate mixture in line with specific project requirements, which they thoroughly wash and dry.

Next, they thin the asphalt cement by heating it up, adding a solvent, or emulsification in water.

Once the manufacturer has heated the aggregate and asphalt cement to the ideal temperature, the manufacturer will mix the two together using industrial mixing machines such as drums or pugmills.

The hardest part of the process is getting the temperature right. To do so, manufacturers must take into account the amount of asphalt to be transported, as well as other factors such as its thickness and compacting.

The Difference Between Hot and Cold Mix Asphalt

There are two basic types of asphalt: hot and cold.

Hot Mix Asphalt (HMA)

HMA is the most common type because its toughness makes it suitable for high demand areas such as busy roads and highways.

As the name suggests, HMA requires the manufacturer to heat both the aggregate and the asphalt cement to a significant temperature for mixing and also when being applied and compacted. The process removes moisture and increases fluidity, which makes it easier to spread.

Cold Mix Asphalt (CMA)

CMA, as you would expect, requires less heating, which equates to a lower production cost.

Quarter inch chip is used as well as proprietary oil with various additives. The result is a soft mixture from which potholes can easily be repaired all year round.

Getting an Asphalt Job Done Right

Now that we've answered the question "how is asphalt made?" it's time to choose a reputable company.

The team at Perrin Construction have been in the business since 1984 and are experts at all sorts of paving projects, large or small.

Get in touch with them today to discuss how they can handle all your paving needs.