The City of Ramsey used scrap tires as lightweight fill for the first time in 57-acre Elm Crest Park. The park, which opened in the spring of 2005, features seven soccer fields.

Roughly 24,000 recycled tires were used to bridge soft soils under a trail that circles the park. The TDA (Tire Derived Aggregate) works like a snow shoe, suspending the trail on top of the soft soils. The trail will be used for walkers, bikers and vehicles used by the city for park maintenance.

Prior to selecting TDA, construction of the trail stopped because the soft soils could not support the construction vehicles. It was a perfect opportunity to try something new, according to Mayor Tom Gamec. “We expect the tire shreds will make the trails last longer and hold up better,” he said. “I really like the idea of recycling tires for a good use.”

The trail was constructed in January. A geotextile fabric was placed under and over the tire shreds. The fabric allows water to go through and drain freely through the tire shreds, but it keeps out soils. Tire chips are a couple inches to a few inches in size. The variation in size allows the material to interlock well, thereby creating a stronger subgrade for the trail than conventional, more uniformly sized material. A layer of sand was placed over the fabric. In some areas, black top was added, too.

In the past, the city has had trouble with tree roots disturbing trails. Mayor Gamec is hopeful that the tire shreds will help minimize disruption from roots in Elm Crest Park.

TDA offers several benefits, according to Monte Niemi, CEO of TDA Manufacturing. "There are several civil engineering applications for scrap tires," Niemi said. "Two main benefits are they provide a stable base for the trail or road, and they have insulating properties which keep frost from causing the surface to heave or settle."

Time and effort on the job site were reduced because TDA can be applied in four-foot increments instead of the usual eight inches of other materials. Niemi also noted that other types of material require more starts and stops to test for various conditions. Another benefit is a well draining sub grade so rain or snow won't cause ponding.

TDA has the approval of federal and state agencies. "In a well designed application, the performance has met or exceeded that of other materials. And, it’s more cost effective," Niemi said. First State Tire Recycling has supplied TDA for projects as small as homeowners' driveways and as large as stretches of Interstate 35.