What is it?
An asphalt grinder (or cold planer/cold milling machine) is a large piece of machinery used to grind away the asphalt surface or down to the base layer. The adjustable depth allows us to remove a small layer (1” to 1 ½”) off the surface for a simple resurfacing, overlay, or patching; or the entire depth of the asphalt (up to 4”) for a full replacement. It is an essential part of the removal process and makes repair, resurfacing, and replacement much faster and easier (and thus more cost-efficient for our customers) than manual removal.
AMS Paving utilizes two different types of grinders depending on the size of the job. The smaller of the two is about 4’ wide and weighs in at a mere 49,000 pounds, and the larger is about 7’ wide and weighs in at a heftier 65,000 pounds. These two are similar in construction in that they both contain a grinding wheel which mills the asphalt, and a conveyor belt which removes the asphalt into a receptacle, otherwise known as: a truck.
How does it work?
Both machines operate the same way, just at different widths. The main component is an internal large rotating drum with carbide blades that grind the asphalt up to the chosen depth (shallower for resurfacing and patching, and deeper for full removal and replacement). There is a space in the center of the drum that collects the pavement grindings where they can be transferred up a conveyor belt. These machines utilize a front-loading conveyor system to remove the pavement grindings into a truck. The truck driver and grinder operator work in perfect synchrony to ensure that all of the grindings are dispensed directly from the grinder’s conveyor belt into the truck as cleanly as possible.
These grindings (unless they contain Petromat or an excessive amount of dirt) are salvaged to be recycled as strong base material. This helps to protect (a) the environment, by reducing waste added to landfills; and (b) your bottom line, by reducing disposal fees and the need for purchasing additional rock base.
Once the old asphalt has been removed, the newly revealed surface will be graded, compacted, and ready for resurfacing, patching, or an application of a full depth of fresh asphalt.