We use asphalt to get to work, home, family road trips, and pretty much anywhere we have to go! It is something that is a part of our daily lives, but we never stop to think about how its made! Asphalt is typically used for heavier traffic areas instead of concrete because of it’s durability and ease of installation. While concrete is often more aesthetically pleasing, it is much higher maintenance, more costly, and prone to cracks and other imperfections. Asphalt also can form cracks and daily wear, but it is a much simpler process to repair while concrete often needs to be replaced. Concrete is a ridged surface that doesn’t allow for any give when pressure is added. Asphalt is much more flexible and will give slightly when weight is added.
The exact process of making asphalt may vary slightly depending on the manufacturer, but for the most part it’s pretty similar!
First, what it is made of?
Asphalt is made of two main components: Asphalt cement and aggregate. Asphalt cement is very different from the cement you used to make handprint stepping stones as a kid. Asphalt cement is the liquid form of petroleum. It has an extremely high viscosity which means it sits somewhere between a solid and a liquid in a dark, sticky mess! The aggregate is often made of sand, gravel, crushed stone, or rock dust.
Did you know that different types of asphalt is used for each layer?
Crazy, right?! The foundational layers are typically made with a bigger aggregate to form a more stable surface and more durability. The visible layers are made with a smaller aggregate to help it lay more smoothly and look a little neater!
How is the cement and aggregate mixed?
A “typical” ratio for cement to aggregate is 1:19 (or 5% cement and 95% aggregate), however that can vary depending on a few factors like weather and projected traffic. In hotter climates, harder asphalt would be used to reduce the amount of give which can cause potential cracks. In colder climates (like Wisconsin!), we use a softer asphalt to make room for freezing and expanding.
Asphalt is typically manufactured at a local plant. It is mixed based on the needs of that specific project. It then gets blended in a large drum (also known as a pug mill or pugger!) and transferred to and brought to the project site using an asphalt paver or finisher. This is the piece of equipment that dispenses the mixture to be spread out and smoothed. This machine will keep the mixture at the precise temperature needed to get a proper application.
What is the difference between hot asphalt and warm asphalt?
Hot asphalt is the most common type of asphalt used. It is, as the name suggests, mixed at an extremely high temperature that has to be maintained throughout the entire process. Warm asphalt is slowly becoming more popular and is a much more eco friendly option. Instead of using high temperatures to mix, emulsifiers are used at warm temperatures to mix. This uses less energy, petroleum, and emits less harmful gasses.
So, in short, asphalt manufacturing is an extremely delicate and precise process that has no rules. Just kidding. Different projects will always have different requirements. Even on the same project site different mixtures and materials will be used!
And the good news? It’s okay if absolutely none of this makes sense to you! That’s why there are skilled and experienced professionals that know exactly what you need! At Armored Asphalt, we got our start in asphalt installation because we noticed a huge lack of development and enginuity to improve out dated practices. We strive to make major improvements in our industry to offer better and longer lasting results!
If you need a professional asphalt contractor, give Armored Asphalt a call today to discuss your project and get started with a free estimate!