Walbec Group


When to Mill and Overlay my asphalt pavement?

Potholes in Asphalt Parking Lot

Milling and overlaying may be a suitable solution when asphalt pavement has surface distress but is structurally sound. Not every asphalt pavement needs to be completely reconstructed. Trust Walbec’s infrastructure experts to help evaluate circumstances and offer customized recommendations based on pavement conditions, traffic volume, stormwater management needs, and budget constraints.

We can also create a customized asphalt pavement maintenance plan to extend the pavement's lifespan, ensure safety, and include scheduled and unplanned maintenance activities before rehabilitation.

One of the most effective reactive maintenance techniques is a mill and overlay. The mill and overlay process involves replacing the top layer of asphalt, which helps prolong the overall life of the pavement and underlying stone layers. However, this method does correct any structural problems, thus making it crucial for the asphalt and stone layers to be in adequate condition.

When considering mill and overlay, it involves the removal of the top layer of asphalt and replacing it with new asphalt. This method is suitable when:

  • Sufficient asphalt and stone base depths
  • No major structural issues or severe potholes
  • Proper slope and drainage
  • Extending the service life is desired

What does minor surface distresses look like, and how poor does an asphalt pavement get before a complete reconstruction is necessary?

Minor surface distress in asphalt pavement can manifest in various forms. Some common examples include:

  • Cracking in pavement may take on various forms, including longitudinal cracks that run parallel to the joint line, transverse cracks that run perpendicular to the joint line, or block cracks with rectangular shapes.
  • Raveling refers to losing small stones from the surface, leading to a rough and porous appearance.
  • Potholes are localized failures when the pavement structure (asphalt and stone layers) has deteriorated, resulting in a depression or hole.
  • Rutting occurs when the pavement surface deforms and creates longitudinal depressions or wheel tracks, most commonly due to insufficient stone below the pavement to support the vehicles.
  • Bleeding refers to migrating excess asphalt binder to the pavement surface, creating a shiny and slick appearance.
  • Alligator Cracking is a specific type of cracking that resembles the scales on an alligator's skin, with interconnected cracks forming a series of irregular-shaped blocks.

The decision to pulverize or reconstruct a pavement is determined by various factors, including the pavement's overall condition, traffic volumes, types of vehicles, and the budget available. The extent of pavement deterioration that justifies this action also depends on these factors that may indicate the need for reconstruction:

  • Structural damage - extensive fatigue, alligator cracking, rutting, or potholes
  • Poor drainage - If the pavement has inadequate drainage, recurrent ponding will accelerate the deterioration by weakening the soil beneath the stone base and reducing the strength of the stone base from the interlock.
  • Inadequate Support - The asphalt pavement and stone base are sometimes not deep enough to handle traffic and vehicles. Also, if the underlying soils are weak, pavement reconstruction is essential. This will help make it stable, durable, and long-lasting.

When do I need to reduce the stormwater runoff when I'm only rehabilitating the pavement that has been here for many years?

Local and state regulations control the decision to reduce stormwater runoff as part of a pavement rehabilitation project. When making improvements to asphalt pavement, it is recommended to consider the advantages of improving drainage. However, there are certain circumstances where it is necessary to decrease the amount of stormwater runoff.

  • Local regulations - Different communities seem to have distinct regulations concerning the threshold for considering stormwater runoff in contemporary society. We will review local regulations and determine how they may impact your project.
  • Environmental considerations - Stormwater runoff can adversely affect nearby waterways due to contaminants and sediment. Projects located near sensitive ecosystems provide an opportunity to protect the waterway and reduce pollution from runoff.
  • Sustainable practices - The utilization of recycled material in asphalt pavement contributes to the reduction of environmental impacts, the preservation of water resources, and the enhancement of infrastructure resilience.

Our team of infrastructure specialists can deliver appropriate site engineering and construction solutions that are safe, timely, and cost-effective, whether for new development or revitalizing an existing one. From surveying and engineering to permitting and construction, we are your one-stop solution.