Two Unpaved Road Sections in Southern Manitoba Incorporating Tire Derived Aggregate: Performance Evaluation - TREK Engineering Inc.
TREK Engineering Inc. evaluated two unpaved road sections in southern Manitoba—approximately 100 m of 5th Avenue NE in Carman and 200 m of Road 20 W north of Winkler—that were reconstructed in summer 2025 using Type B tire-derived aggregate (TDA). Existing roadbeds were excavated about 7 m wide and 2 m deep; two loosely placed 300 mm TDA lifts were compacted with an excavator (target ~50% thickness reduction), then covered with the excavated alluvial soils (silty sand at Carman, sandy lean clay at Winkler) and a thin gravel surface. After the 2026 spring thaw and heavy June rainfall, rutting returned in the same localized “problem areas.” A July 2026 investigation of eight test holes, moisture profiles, grain-size testing, and surveyed cross-sections found the reused backfill was likely placed wet of optimum, limiting compaction; the soils are highly frost-susceptible (F4); TDA layers sat at or below the water table and ditch inverts (so they could not drain or act as a capillary break); and the absence of a geotextile separator allowed fines to infiltrate TDA voids.
Road performance was therefore governed mainly by the condition of the soil cover rather than by the TDA itself. The report concludes that TDA can still help stabilize weak subgrades if it is placed above the anticipated water table and ditch invert, fully encapsulated in a compatible non-woven geotextile, given at least 0.5–0.6 m of well-compacted cover moisture-conditioned near optimum, and used with adequate surface gravel. A practical repair approach is outlined: leave the existing TDA in place, excavate to about 900 mm, install a new 300 mm encapsulated TDA layer, compact 0.5 m of conditioned fill, and restore the gravel wearing surface. The study underscores the need for site-specific groundwater data, moisture control, and proper encapsulation when using TDA in Manitoba’s alluvial soils.
TIRE DERIVED AGGREGATE (TDA): A STUDY ON APPLICATIONS, ENVIRONMENTAL PRODUCT SAFETY. Prepared for TSM by Atiyeh Arvin
The extensive generation of end-of-life tires (ELTs), with over one billion discarded globally each year, poses significant environmental and public health challenges. To address this issue, Tire Derived Aggregate (TDA) has emerged as a sustainable and versatile solution, repurposing shredded tires for various civil and environmental engineering applications. This report provides a comprehensive analysis of the properties, applications, advantages, and potential barriers associated with the use of TDA.
TIRE-DERIVED AGGREGATE (TDA) prepared for CATRA by Kelvin Igwe
Worldwide, around one billion tires reach the end of their useful life every year. This underlines the importance of managing scrap tires in an environmentally responsible and productive manner so that they don’t simply go to landfill sites where they put our environment and health at risk.
Rubber Modified Asphalt (RMA) prepared for CATRA by Chahneet Sidhu
Have you ever wondered what happens to your old tires? Recycling agencies in each Canadian province and territory ensure tires are recycled safely and responsibly. In 2018, over 487,000 tonnes of Canada’s end-of-life tires (ELTs) were diverted from landfills and made into environmentally responsible products such as Rubber Modified Asphalt (RMA).