Maine road experiment uses 20,000 recycled tires to mitigate frost damage

In 1992, an engineering experiment on Dingley Road in Richmond, Maine, utilized 20,000 recycled tires to mitigate frost damage to road infrastructure. The project was a collaborative effort involving the University of Maine and the U.S. Army Cold Regions Research and Engineering Laboratory, led by engineer Dana N. Humphrey.

The tires were shredded into fragments of approximately five centimeters and distributed in five different sections. These sections featured tire layers ranging from 15 to 30 centimeters in thickness, which were then covered by 30 to 61 centimeters of granular material. This design aimed to reduce frost penetration depth and minimize ground heave caused by freezing and thawing cycles.

Research published in 1995 indicated that the shredded rubber helped slow heat exchange and improved drainage. Specifically, sections with a 15-centimeter tire layer covered by 30 centimeters of gravel showed a reduction in freezing of between 22% and 28% compared to untreated sections, while thicker layers achieved reductions between 15% and 37%.