Asphalt Grinding & Milling Services
Milling involves the controlled removal of uneven or damaged pavement to reach a desired depth of surface. Milling is generally used when an existing surface is sensitive to a raised elevation which may disturb existing drainage patterns. Maintaining transitions into existing curb or walks will also eliminate trip hazards. Asphalt is a flexible material that lends itself well to the grinding and milling process.
Milling grinds and removes the asphalt and takes it to a stock yard. Pulverization grinds the asphalt surface into the existing stone base in an attempt to strengthen the base. It eliminates the costs of removal of ground asphalt and it also reduces the amount of new stone that needs to be imported. Pulverization lends itself well to surfaces that can stand to be elevated by a few inches or more. Generally, parking lots roads without border curb will fall into this category. In many cases with recreational surfaces such as tennis courts and track, this is a viable option.
Benefits of Milling, Grinding and Pulverization:
- Restoration of drainage flow
- Removal of ruts and smoothes washboarding
- Materials can be recycled and used in new asphalt pavement or stockpiled for a later time
- Can be done quickly with little interruption to traffic flow
- Cost-effective and only involve necessary corrections
Other Considerations of Cold Milling
Usually, parking lots or roads in poor condition are candidates for the milling and pulverization process. Often, serious cracking has occurred in the old surface, and water has been penetrating through these cracks for years. In some cases, even when cracks form, water does not penetrate but still sheds off. When water does penetrate through the surface, it will cause the subgrade and stone base to be soft and will tend to yield to construction traffic. When this happens, there are a few options to consider.
If it is a hot, dry time of year, then the sun and heat will help to reduce the moisture levels and cause the foundation course to harden. In some cases, the water is too deep and the sun has no effect. Aeration is also a possibility in this instance, but if the water has penetrated below the stone grade to the dirt subbase, then aeration is complicated by the necessary removal of the foundation course.
Undercuts may be an option. This involves the removal of the saturated material and importing something suitable to take its place. Sometimes, the condition is so soft and so deep that it requires some form of bridging. In this case, the only suitable import material would be stone and some form of geogrid in order to provide the additional needed strength to correct the soft condition.
Another possible alternative is Cement Stabilization. Cement Stabilization helps to bridge the distressed condition by grinding dry portland cement into the the base and adding water. The cement helps to rigidify the surface making it suitable to the planned weight of traffic for the proposed surface.
A suitable nonyielding foundation course is a necessary part of any structural system. Attending to foundation course issues is inherent in the process to building a good structural system. Experience is the best tool to keeping the process as cost-effective as possible. While experience can often foretell problems before the process begins, it is not 100% assured. Good communication between all parties involved is the best remedy to reasonably control the process and get the best results possible.
Read more about milling on our FAQs page. Are you wanting to refresh your asphalt surface? Contact Raleigh Paving today, and learn more about the many services we offer. We proudly serve businesses throughout Raleigh, Durham and Chapel Hill, as well as many other areas across the state.