DULUTH, Minn. -- Researchers at the University of Minnesota-Duluth may have the answer to our pothole problem.
"I think everybody recognizes that road deterioration and potholes are a real problem. It's a huge cost to consumers and to motorists on an annual basis just for damage to their vehicles," said Larry Zanko with UMD's Natural Resources Research Institute (NRRI).
Zanko, principal investigator, is part of a team fine-tuning two new ways for pavement patching and repair--both taconite-related. Zanko believes both technologies, 10 years in the making, are promising and provide a quicker and more permanent fix, leading to a more cost-effective solution.
The first is rapid repair--a taconite-based pothole and pavement repair compound. The NRRI developed and patented the compound. NRRI testing has shown it has a set time of less than 15 minutes and is drivable in 30 minutes. This method can be used on both concrete and asphalt.
In an NRRI research project, a field test on the Highway 169 bridge deck near Keewatin, Minnn. performed "very well" for over three years following its installation in November 2010. However, Zanko said one of the factors determining how long a repair will last is the condition of the existing pavement.
"The whole idea is to develop a repair that can be done quickly, easily and is something that will last a lot longer than a typical repair. Often you'll see a crew out repairing a hole and then perhaps the next week or even the next day, might have to go out and fix that hole again," Zanko said.
Zanko also pointed out that quicker repairs will benefit not only drivers--minimizing the impact on traffic flow--but maintenance crews.
"If a repair can be done more quickly and last longer, that puts them out of harms way for a longer period of time," he said.
According to a research project, it also has the potential to save maintenance departments thousands of dollars in labor costs each year.
The second method NRRI is exploring is microwave-based--heating the existing pavement to the point that it becomes part of the repair.
Crews have tested this type of treatment in Anoka, among other places. It can only be used on asphalt.
According to Zanko, the treatment can be used year-round but is especially effective for patching potholes in the wintertime. This microwave-based patch system uses recycled asphalt pavement and recycled asphalt shingles, as well as a bit of taconite material to enhance microwave absorption.
"Both of the approaches we're taking we're making use of, or trying to make better use of, what's considered to be waste materials. Whether it's from the taconite industry or even like I mentioned for the microwave repair, simply using recycled asphalt," Zanko said.
Researchers are currently working with the Minnesota Department of Transportation and plan on expanding their research this year.
According to Zanko, their main focus in 2017 will be refining the rapid repair method so it does not require hand mixing.