March 2018 Vol. 26, No. 1

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New guide helps you choose the best pothole patch


Selecting the appropriate patching method and materials varies depending on several factors, including the size of the pothole and its location on the roadway. A new guide and accompanying how-to cards from the Minnesota Department of Transportation (MnDOT) help road crews choose patching methods that match specific repair conditions.

“We wanted to develop a decision tree for choosing the right pothole repair method that could be laminated for use in the field,” says Susan Lodahl, assistant state maintenance engineer with the MnDOT Office of Maintenance.

Researchers from the University of Minnesota Duluth reviewed existing literature to identify the four repair methods best suited to Minnesota: cold mix, hot recycled asphalt, mastic material, and mill-and-fill with hot-mix asphalt. Next, they identified five sites near Duluth, where they oversaw 20 pothole repairs. They then monitored these repairs for two years to assess the methods and their best applications.

pothole guide

Using the findings from this study, researchers developed decision trees in both flowchart and how-to card form to help road crews choose the most suitable method for each repair (see samples at right). They also compiled best practice guidelines for patching method selection, placement, compaction practices, and moisture control to provide further guidance.

MnDOT plans to mail a laminated poster (folded up like a map) with the decision trees to all Minnesota State Aid cities and counties, as well as to MnDOT operations staff. Additional copies are also available.

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