Asphalt paving has been studied and improved over the years. It is a harmonious blend of materials and techniques that result in a smooth, durable, and reliable surface that we all depend on daily. When properly constructed, an asphalt pavement can last many years, supporting heavy traffic and endure weathering from harsh conditions. Andersen Asphalt & Striping would like to highlight the different layers used when constructing asphalt and why each one is essential to the longevity of a high quality asphalt surface.
Subgrade Layer of Asphalt Pavement
The subgrade is the “foundation” layer of the asphalt paving. It is the local or native soil on which the pavement is constructed, and its quality can greatly influence the longevity and performance of the asphalt surface. Before laying asphalt, the subgrade is usually compacted and treated to enhance its strength and stability. If the subgrade is weak or improperly prepared, it can lead to premature pavement failures like cracking or rutting. This is why ensuring a stable and well compacted subgrade is essential to the asphalt pavement.
Asphalt Aggregate Base Layer
The aggregate base layer or sometimes called the base course, is the layer directly above the subgrade. This layer consists of crushed stone or gravel and serves as the primary load bearing layer in the pavement design and or structure. The base layer provides structural support, helps distribute loads to the subgrade, and improves drainage within the pavement. Given its structural importance, the base course must be made of a high quality, well graded aggregates compacted to the right density.
Binder Layer of Asphalt
The binder layer, also known as the base asphalt layer, is placed over the aggregate base. This layer is composed of a hot mix asphalt (HMA) that contains a higher amount of larger aggregate and more asphalt binder, resulting in a product that is sturdy and resistant to shearing forces from heavy traffic. The binder layer acts as a bridge, transmitting the stresses and strains generated by traffic loads from the surface layer down to the base and subgrade layers.
Asphalt Surface Layer
The surface layer, often called the “wear layer” is the top layer of the asphalt pavement and the one we interact with daily. It consists of smaller aggregates mixed with an asphalt binder, providing a smooth and skid resistant surface for vehicles. This layer is designed to withstand traffic loads and weather elements while providing a safe and comfortable driving experience. The durability, texture, and even color of the asphalt surface layer greatly impacts the performance and aesthetics of the road.
Asphalt Parking Lot & Road Pavement Resurfacing, Replacement & More in Reno, Elko, Henderson, North LV, Paradise, Spring Valley, Sunrise Manor, Las Vegas, NV | State of Nevada
Understanding the layers of asphalt and their importance is important as it helps to recognize the complexities of paving projects. Each layer plays a unique role in the overall structure and performance of the pavement, from supporting traffic loads and providing a smooth driving surface to enhancing drainage and promoting stability. Ensuring the quality and proper construction of each layer is key to a durable, longevity, and efficient asphalt pavement. For quality asphalt installation, repairs and more, contact Andersen Asphalt & Striping and schedule our services today.