Tire Derived Aggregate (TDA) was the preferred solution to fix a stretch of residential street in Grand Rapids, MN. The paved street, originally built over a deep peat swamp, had settled four feet in some areas. An innovative solution was needed, according to Tom Pagel, office manager, RCM Associates, Grand Rapids. “Considering the soil tests, and with recommendations from Braun Intertec, we went right to tires without seriously looking at other options,” he said.

RCM reconstructed three blocks of the street in the fall of 1997 using TDA as fill over the soft soil. One year later, RCM announced that TDA had demonstrated that it can withstand a Minnesota winter. RCM continues to monitor the road to watch for signs of settlement or cracking. “This project is well documented,” Pagel said.

Based on his experience with R.-T.E.A., he believes they would use tires again.

In the beginning of the project, however, there was some concern. It was a learning experience for RCM and the city. “We were scratching our heads and saying, ‘If this doesn’t work, we’re shot,’” Pagel said. The residents in the area were supportive but also wondered if it would work.

Monte Niemi, C.E.O. of First State Tire Recycling, says TDA was an ideal solution in Grand Rapids for several reasons:

· Recycled tire aggregate weighs approximately 550 pounds per cubic yard compared to 2,800 pounds per cubic yard for gravel fill. · Lightweight-tire-fill material costs considerably less than other alternatives. · TDA performs well over soft soils.

· The pieces compact and interlock providing a stable foundation in sandy and wet soils.

· Tire chips are very porous and drain moisture from the granular material placed over the chips.

· Recycled tire fill material works as a thermal blanket to reduce the effects of cold on the subgrade beneath the chips.

· Tire chips prohibit frost from disturbing the driving surface.

· Road projects that use recycled tire material make a good, environmentally friendly use of scrap tires.

In addition to working well in wetlands and over other marginal soils, TDA is also often the best engineering solution in terms of road settlement for any roadbed application, Niemi said.

NOTE: First image is from 1997; all other images are from 2018.