Abstract Manager

Saskatchewan recycles all tires, including passenger car and light truck tires, agricultural tires, and semi tires. It is environmentally and socially acceptable to recycle tires, and agencies in North America have been doing so for years. Recycling tires is important because scrap tires take up landfill space, pose a risk of fire when stockpiled incorrectly, hold water when not shredded, and can help conserve natural aggregate resources, depending on the application. Tire Derived Aggregate (TDA) is an engineered material made from shredded tires. TDA has been used in civil engineering applications as lightweight fill to build embankments, roadway ramps, weigh scales, backfill for retaining walls, and to repair frost heaves for over 40 years.

In 2022, the Saskatchewan Ministry of Highways (ministry) constructed the ministry’s first highway embankment with TDA as lightweight fill. A greenfield project site on a new section of Highway 39 near Corinne required a large embankment fill for the southbound lanes and had in-situ soils that would benefit from the frost protection properties that TDA offers. TDA was utilized as lightweight fill in a location where the road embankment section was being built over an existing dugout. The TDA embankment section was constructed with a total of 6,332 cubic metres of TDA. Using a conversion of 100 tires per cubic metre of TDA, approximately 632,000 tires were recycled. A 2.95 m thick clay fill embankment with an additional soil surcharge layer of 0.75 m was placed on top of the TDA layer and allowed to settle prior to further construction. The surcharge load was removed to accommodate the pavement structure, and a flexible asphalt concrete pavement structure was constructed on top of the embankment, and the road was opened to traffic in 2024.