When most people think of asphalt roads, they imagine the smooth, black surface of a freshly paved road. While the roads you drive on may look like one continuous layer, asphalt roads are actually built and installed with several layers. Each layer serves a different purpose and must be installed correctly in order for the road to withstand heavy traffic and weather conditions. Read on to find out why asphalt roads are installed in layers rather than 1-thick layer, despite their initial appearance.
Why A Single Thick Layer Doesn’t Work for Asphalt Roads
You might be wondering if a single layer of asphalt is good enough for driveways and parking lots, why can’t the same method be used for roads? The answer is simple – traffic and weather make a single thick layer of asphalt inadequate for roads. Asphalt roads must be able to withstand a tremendous amount of weight and force from cars, trucks, and other vehicles.
In addition, they are exposed to the elements 24/hours a day, 365 days a year. This means that they must be able to withstand extreme weather conditions, such as freezing temperatures and direct sunlight. If the roads were made from a single thick layer of asphalt, they would crack and crumble under the immense amount of pressure and weight, and the inclement weather would wear it down rapidly.
The Importance of Layers in the Asphalt Road Installation Process
Installing asphalt roads in layers is the best way to create a road that is durable and long-lasting. Each layer serves a specific purpose and contributes to the overall strength and stability of the road.
- subgrade, is made up of compacted soil or gravel. This layer is installed on top of existing soil to create a stable foundation for the subsequent layers, and prevents the asphalt from cracking, shifting, or sinking under the pressure and weight of the vehicles.
- The base course, also sometimes called the subbase, is the second layer in the process. This layer is usually made up of compacted gravel, and its main purpose is to provide drainage for the road. Proper drainage is essential to preventing water from seeping under the asphalt and causing it to crack or crumble.
- The binder layer is the third layer in the process, which sits between the base course and the wearing course. It is made up of a mixture of asphalt and gravel, and serves to bind the subgrade and base courses together. This layer absorbs the majority of the stress that would otherwise be sustained by the wearing course and as such, provides additional stability and strength to the road.
- The fourth layer is the wearing course, which is also known as the surface course or the top course. As its name suggests, this is the layer that you see and drive on every day. The wearing course is made up of a mix of asphalt and aggregate, which provides a smooth, even surface for vehicles to travel on. The wearing course also protects the road from weather damage, while providing additional traction and noise reduction.
As you can see, each layer in the asphalt road installation process serves a specific purpose. When these layers are installed correctly, they work together to create a strong, durable road that can withstand heavy traffic and extreme weather conditions. If you have any questions about asphalt roads or our installation process, give us a call at (407) 618-9646 and one of our team members will help you out!