Before doing any work, a Lakeland parking lot paving contractor will carefully evaluate the quality of the subgrade or the existing soil on which the pavement will be laid. Even if the pavement needs only repair and partial replacement, a contractor still needs to check the subgrade. This ensures that the subbase, base course, and asphalt pavement are laid on sturdy and durable soil.
So, what happens if there is a problem with the subgrade? If there is already an existing asphalt pavement, the contractor needs to remove that asphalt, dig out the soft part of the subgrade, and fill it with two-inch rock and aggregate. The aggregate must be well-graded. It must at least be 0.75-inch top-size aggregate with high dust content. This is also commonly used for the aggregate base.
The contractor will remove the bad soil or the humps and soft spots. Why? When this eventually collapses, the top pavement, no matter how sturdy it is, will also give in and collapse. The contractor has to replace the soft spot with 12 inches of two-inch rock and two inches of graded stone. Aside from the possible collapse of the subgrade, the contractor is also looking at making proper drainage with no low spots.
Again, the leveling of the subgrade is essential to the overall stability of the pavement. Since the drainage pipes run through the subgrade and subbase layers, they could potentially face problems in leaking waters. If the subgrade isn’t strong enough to handle the possible flooding that occurs on drainage incidences, the pavement will collapse with nary a thought.
Part of the preparation work also involves cutting the grass close to the side of the driveway, as well as cleaning the surface of the old asphalt. The contractor also has to grind the sidewalk so the contractor can apply the new layer of pavement. After this, the sub-layers have to be thoroughly compacted to ensure the stability of the layers of subsoil that will be placed on top of the subgrade.
The same process is done on residential and commercial parking lots and driveways. Before a Lakeland parking lot paving can be constructed, the contractor must evaluate the conditions of the soil to make sure that it is ready for the stability of the pavement. Some contractors even hire an experienced geotechnical engineer with a working knowledge of local soil conditions to determine the health of the subgrade.