Environmental freezing and thawing cycles, oxidization due to the sun, snow plows, and general wear and tear can damage the first layer of asphalt pavement. This damage often is referred to as alligator cracking and the damage is confined to only the first layer of asphalt pavement. The base course of the asphalt and the sub base of gravel are still unaffected at this point in the life cycle of asphalt. Instead of completely tearing out and replacing these areas, a cold plane diamond tipped asphalt milling/grinding machine allows for economical repair.

Asphalt milling/grinding can be a green solution to winter’s effects. The process begins with a cold plane milling/grinding machine with diamond teeth that break up the pavement but leave the sub base intact, if it is still unaffected. The ground-up asphalt is removed from the work site and recycled at an asphalt manufacturing facility. Next, the areas of the driveway or parking lot that were milled/ground away are sprayed with SS1H tack coat to bond the new asphalt to existing asphalt then all milled/ground areas have a layer of hot mix asphalt applied to level out the surface to proper grade. Finally, 2” of additional hot mix asphalt are applied to the surface and compacted with a vibratory roller. For residential customers, the final 2” layer of asphalt is usually recommended for the entire surface as it will look like an brand new driveway.

The cold plane milling/grinding option has many advantages compared to a standard overlay. An overlay does not address the cracked and alligatored areas of the first layer of pavement. When a simple overlay is completed these unrepaired cracks reflect back up to the surface usually within 12 months. The result is disappointing for both business and homeowners. A milling/grinding machine removes these cracked and damaged areas diminishing the onset or result of reflective cracking. If left untreated the cracks in the first layer of pavement will allow water to penetrate and erode the base layer of pavement, leaving a complete tear out and total replacement as the only viable option.

Aside from being an environmentally-friendly process, asphalt milling can also be more cost effective than the rip out and replace method of road or driveway repair. Consumers save money as there is less trucking involved when only removing partial pavement, less man hours to complete the job, and less hot mix asphalt is required to restore the condition of the parking lot or residential driveway. This economical repair extends the life of the treated pavement for 8+ years unlike patching or overlays which may begin to fail as soon as year one.

Currently, most paving companies only offer industrial-sized mills for large projects such as highways or large apartment home complexes. Very few companies own a mini cold plane mill for residential and mid sized commercial projects. If you have a driveway or parking lot that requires a smaller mill, research your options and find a vendor like Sommerset Paving that can offer a mini-mill for medium-sized projects.

Milling/grinding the first layer of damaged pavement saves money compared to complete removal and replacement. Other benefits of milling/grinding include:

• Extends life of pavement for 8+ years compared to 1-2 years with overlayment or patching
• Leaves a level surface with no raised asphalt edges that can be caught up and ripped away by snow plow blades
• Costs consumers less money in man hours, materials, and trucking
• Saves the base course of asphalt from further damage