Patching pavement with microwaves and magnetite

On Wednesday, I had a chance to watch a demonstration of a uniquely Minnesotan pavement patching technology that combines an industrial-strength microwave with a special asphalt mix. What makes it “uniquely Minnesotan?” In addition to having been developed by University of Minnesota researchers and a Monticello-based company (and with some funding from MnDOT), this innovative method involves a special asphalt mix using magnetite, a mineral that abounds on Minnesota’s Iron Range.

It also addresses a very Minnesotan transportation problem: winter pavement repair. In the video above, Kirk Kjellberg of Microwave Utilities, Inc., highlights some of the benefits of using the 50,000-watt microwave to heat the pavement during patching. In addition to creating a longer-lasting patch, the microwave is considerably faster than many alternative techniques. The technology is still relatively new, but its supporters claim it allows for pavement repairs in the middle of winter that are as strong and durable as the ones road crews do in the summer.

The demonstration, which was organized for members of the Local Road Research Board, took place at MnDOT’s District 3 training facility in St. Cloud.

See also:

5 thoughts on “Patching pavement with microwaves and magnetite”

    1. Hi, thanks for your comment. My understanding is that the technologies are similar, but different. Kirk Kjellberg (interviewed in the video above) told me that infrared takes a longer time than microwave; however, I am not an expert in this area. The Minnesota Business article linked above discusses some of the differences between infrared and microwave technology. You might also contact the company directly to ask them.


  1. Thanks for sharing this new concept. So I think this magnitude and microwave patching technology may overcome the disadvantage of old methods in asphalt driveway construction

  2. Thanks for sharing this new concept. So i think this new magnetite and microwave technology might overcome the disadvantages of old technology in asphalt driveway construction.

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