The Importance of Grading
If you’ve ever driven across a freshly paved parking lot, you might have noticed that it was billiard-table smooth. The reason for that is a process called grading, and it’s one of the most important steps in the construction of new pavement.
What is Grading?
Grading is the process of evening out the lower layers of material before paving. Beneath any asphalt, there is a layer of native soil called subgrade and a layer of stone mix called base.
The area must be cleared of debris before applying asphalt. The native soil here in Virginia is uneven and contains soft spots, rocks, vegetation, and large roots. Engineers carefully inspect and excavate the area to clear it of debris before grading the land.
Then, the land is graded to the right slope and camber. Paving on a slope means taking into account the natural grade of the land as well as the desired grade of the paved surface. The terraformed land is then compacted into a dense layer, ready to be built upon.
The next step is to apply the base. The base is made up of sand, lime and gravel, and it serves two purposes. Its primary function is to aid in drainage. If water flows directly into the subgrade, it will quickly wash away the soil and cause the asphalt to crumble.
The subbase also serves as a foundation for the asphalt. It assists in evenly distributing weight across the surface and ensures stability under heavy loads.
Why is Grading Important?
Grading not only ensures a level layer of asphalt, it is essential for the stability and longevity of a paved surface.
Water is the primary concern in paving. Grading allows engineers to control how water is directed away from the surface and into the ground or gutter.
Poor grading can cause problems such as pooling, corrosion, or even flooding. If you’ve ever had to navigate around big puddles after a storm, chances are the area was improperly graded. This is especially important in Virginia, which is prone to year-round rainfall.
Grading is also important for maintaining the structural integrity of the pavement. Just like buildings need a foundation, so does asphalt. Asphalt is naturally quite flexible, which makes it shock-absorbent and weather resistant. A properly graded base helps the asphalt withstand the wear and tear caused by traffic and heavy loads.
Grading by Gallaher Seamless Paving
Here at Gallaher Seamless Paving, we understand the unique difficulties posed by the Virginia climate. Before construction begins, our experts take these factors into account to ensure quality and durability. Contact us today to schedule a consultation for your next paving project.