Tag Archives: microwave

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.

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‘Three Ways to Cook a Pothole’

In April, we posted about an innovative pothole-filling technology being developed by the Minnesota Department of Transportation and the University of Minnesota, Duluth. The technique involves zapping pothole patches and the surrounding pavement with a special truck-mounted, 50,000-watt microwave. Researchers have found that heating the base and the patch material at the same time creates a stronger, longer-lasting bond that provides for a more permanent pothole fix.

Last week, the MnDOT/UMD microwave technology found its way into a new MnDOT video (above) that also explores two other experimental pothole-patching methods. One involves using a large “electric oven”-type heating element instead of a microwave. The other utilizes a new exothermic (i.e. heat-generating) asphalt mixture containing taconite from northern Minnesota mines. The video compares the potential benefits of all three of the new technologies, which the department hopes will someday lead to “more pothole-patching power for the taxpayer dollar.”

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In the news: innovative U of M and MnDOT pothole repair technology

Last night, KARE-11 News featured innovative pavement repair research sponsored by MnDOT. In a public-private partnership, Larry Zanko of the Natural Resources Research Institute at University of Minnesota Duluth connected with Krik Kjellberg’s company to microwave a mix of asphalt and magnetite in road holes, creating a long-lasting pothole fix.