What is Asphalt Milling?
Asphalt Milling is the process of removing asphalt from the surface of a parking lot or roadway by skimming off the top layer of the existing asphalt at varying depths depending upon need.
Why is Asphalt Milling Important?
As asphalt pavement progresses through its performance life-cycle, its appearance diminishes over time. Fine hairline cracks spread and deepen within the asphalt. Without ongoing maintenance, water may enter through cracks and holes may form, undermining the substrate. In this case, the most effective form of repair is to remove and replace the deteriorated area.
In addition, the base rock underneath the asphalt may deteriorate over time due to hydrostatic pressure. These soft spots and depressions eventually manifest themselves in the surface asphalt. If this occurs over a large enough area, it may be necessary to mill off the entire asphalt layer in order to properly repair and re-compact the base rock.
Finally, when considering re-paving a parking lot or roadway, it is important to consider the existing elevations of the static elements such as curbing, gutters, sidewalks, drainage, and other fixed structures adjacent to or existing within the asphalt. In order to preserve the height of these items, it may be prudent to mill off the same depth of asphalt you are re-paving first. Milling prior to re-paving provides a scarified and uniform surface for better asphalt adhesion.
How is Asphalt Milling Performed?
Asphalt Milling is performed with either a milling machine, or a milling head attached to a skid steer. In either case, the machinery traverses the surface of the asphalt while the ‘teeth’ of the miller grind up the asphalt to a very specific depth. The millings are collected and trucked off-site, and a clean-up crew follows behind using a box sweeper to collect any remaining asphalt.