By KAREN LAGRANGE COX
Have you ever wondered why potholes are repaired and filled before laying a new road overlay? Establishing a foundation under the pothole is important for properly filling and repairing it, providing a solid foundation for the new road overlay. If the pothole is not fixed beforehand, parts of the new overlay could fall into the empty space left by the pothole.
Steps for New Road Overlay
Remove Existing Overlay
The first step in preparing a road for a new overlay is to remove the existing surface through demolition and then clear the debris from the roadway.
Slope and Grade
The road must be properly graded and sloped before laying the new overlay to ensure effective water drainage. Inadequate drainage can lead to water build-up, resulting in road damage such as cracks and potholes.
Construct a Subbase
The key component of the new overlay is the road subbase. It’s a layer of material placed above the subgrade to support the road’s base course and surface course. The subbase is intended to evenly distribute the load from the pavement layers onto the underlying subgrade, reducing the risk of structural failure. Additionally, the subbase is crucial for managing moisture and maintaining stability.
Binder and Surface Course
After laying the subbase, a binder layer is applied using a large aggregate mixed with oil to create a strong and durable overlay.
Install New Surface
Once the aforementioned tasks are finished, the installation of the new overlay can commence.
Install Butt Joints and Transitions
Butt joints and transitions are used to transition existing overlays to meet new overlays for smooth transitions for both drivers and pedestrians. The butt joints and transitions additionally ensure grading and water run-off are appropriate.
The Final Roll
A roller truck is used for the final roll of the new overlay to ensure that no small bumps of aggregate or stones stick out.
Author’s Note: I’d like to express my gratitude to Mel Bertrand, the Public Works Director of Broussard, for confirming the accuracy of these steps.
