NRRI demonstration fills city potholes

A man in a yellow vest kneels as he smooths black material with a gloved hand on a cement street.
September 24, 2018

What happens when you mix innovation with waste rock and potholes? Hopefully, a new road repair that lasts.

“This project is a great example of NRRI innovations to reduce waste and find value in our natural resources." - Rolf Weberg

It's a weird trifecta: waste taconite rock, potholes and NRRI innovation. But one that put a lot of smiles on faces.

In September, the City of Duluth happily offered up some potholes to demonstrate a recently updated road repair "recipe" developed and patented at NRRI. The goal is to find alternative and valuable uses for waste taconite rock and other mineral materials from Minnesota’s Iron Range.

“This project is a great example of NRRI innovations to reduce waste and find value in our natural resources,” said Rolf Weberg, NRRI Executive Director. “And those of us who live in the Northland can sure appreciate a long-lasting pothole repair.”

The road repair material is targeted to set to a hard, durable patch in about 10 – 20 minutes, depending on conditions. The hope is that it can solve some pothole repair challenges, like cold weather applications and endurance over many seasons.

Advanced Road Patch LLC, a small company whose operation is based on the Iron Range, purchased the license to commercialize this product from the University and has worked with NRRI to continue its evolution and evaluation.

As company president John VanderHorn explained, “Advanced Road Patch LLC licensed the patent for the patching system because we believe it has unique properties that make it a very useful tool in a road maintenance crew’s toolbox.”

NRRI is also receiving project support from MnDOT and the Minnesota Local Road Research Board (LRRB). The Iron Range’s magnetite resources provide the key reactive component that, when mixed with a common chemical reagent, allows the material to be poured into a pothole or road fissure before hardening.

“We are excited to partner with NRRI to find creative solutions for a rampant issue that plagues our city and many others across the nation,” said City of Duluth Mayor Emily Larson. “Short term patching is hard and frustrating work. This material could maximize our staff resources and provide tangible results. We thank NRRI for bringing forth this new technology and look forward to seeing the product advance.”

This demonstration project with the City of Duluth will allow NRRI to further modify and test the product for durability in a real world application, and will also allow for testing of equipment to make the job faster and simpler for maintenance crews.