Tire Derived Aggregate Drawing Industry, Engineering and Environmental Support

Tire derived aggregate (TDA) is not a new material.  It got its start in the early nineties as “tire shreds” — the first material derived from downsizing and processing scrap tires.

There were no specifications for the material and no uses. But researchers, engineers, academicians and tire recyclers soon recognized the engineering properties in the tire shreds and set about establishing standards, size gradations, specifications and adopted the name– tire derived aggregate–to differentiate it as a standardized material.

Today, tire-derived aggregate is used in various civil engineering projects as a lightweight, durable, and cost-effective alternative to traditional aggregates. TDA offers several benefits, including improved drainage, enhanced insulation, and reduced lateral load, however widespread use of tire derived aggregate remains a challenge.

The Tire Industry Association (TIA) has launched an initiative that seeks to advance the use of TDA by engineers, public agencies, and private-sector stakeholders as a proven solution for geotechnical challenges that also provides beneficial use of end-of-life tires.

The Association released a comprehensive Statement of Work on Tire-Derived Aggregate (TDA), outlining the performance, applications, and environmental benefits of using TDA in modern infrastructure.

The document highlights how TDA—a lightweight, free-draining material produced from recycled tires—can enhance the performance and sustainability of civil engineering projects in three key areas: roads, retaining structures, and stormwater management.

Dick Gust, CEO of TIA said the document serves as both a technical resource and a call to action for wider adoption of TDA in infrastructure projects across the country.

All TDA applications described in the document use material that meets ASTM D6270-B standard for TDA, ensuring consistent performance across road construction, structural backfill, and stormwater systems, Gust said.

For road construction, the document identifies subgrade stabilization and frost prevention as major challenges and outlines the benefits and roadway improvements achieved with TDA.

TDA offers a sustainable and effective alternative to traditional aggregates, mitigating issues such as frost heave in colder climates and pavement buckling in warmer regions. Its hydrophobic properties and lightweight nature improve subgrade drainage, extend pavement life, and reduce maintenance costs.

In walls and bridge abutments, conventional soils used as backfill behind retaining walls and bridge abutments exert high lateral loads, particularly when saturated. Freeze-thaw cycles can further destabilize structures through moisture expansion and soil creep, often resulting in premature wall failure.

When used as backfill, TDA reduces lateral earth pressure by more than 50% compared to conventional soil. Its drainage capabilities and thermal insulation properties make it ideal for prolonging the life and performance of retaining structures in both residential and large-scale transportation.

In water management, stormwater detention and pollutant capture are major concerns.

Urban runoff from rain events carries a high load of pollutants during the “first flush.” Traditional stormwater systems often lack the capacity to capture, retain, and filter this initial surge, resulting in flooding, erosion, and contamination of natural waterways.

TDA supports green infrastructure efforts by serving as a cost-effective material for stormwater detention and

infiltration systems. With high water storage capacity and contaminant filtration properties, TDA plays a vital role in reducing urban runoff, flood risk, and water pollution.

TDA not only solves real-world engineering problems, but it also supports TIA’s ongoing efforts to promote environmentally responsible tire recycling. By creating markets for end-of-life tires in construction and infrastructure, TDA helps divert millions of tires from landfills each year.

TIA continues to work closely with engineers, government agencies, and industry stakeholders to support the adoption of TDA through education and ongoing performance documentation, Gust said.

Environmental Support Advances

In parallel, environmental research continues to address what happens with TDA in real life application to determine the efficacy and cost-effectiveness of the application of tire derived aggregate (TDA) in stormwater treatment and management systems.

A final report titled Research Needs for the Sustainable Application of TDA in Stormwater Infiltration and Treatment released in February 2025 concluded a three-year study in which researchers reaffirmed that TDA is an excellent means of retaining phosphate (soluble reactive phosphorus) in stormwater runoff.

The report reveals that TDA, when integrated into stormwater systems, fosters double the biofilm growth compared to stone. This biofilm plays a crucial role in capturing metals like zinc, copper, and iron that may leach from the TDA. Moreover, TDA showcases remarkable efficiency, removing dissolved phosphorus at a rate exceeding 95 percent

While there was a measurable release of PFAS from TDA, the concentrations were relatively low and appeared to be similar to typical urban concentrations, including residential land.

Traditional TDA (Trad-TDA) and wire-exposed TDA (WE-TDA) were used in this study. Traditional TDA is categorized as ASTM 6270 Type-B TDA while wire-exposed TDA is a manufacturing by-product and currently does not have a well-defined market. Both types of TDA are manufactured from tires discarded from tire stores and shredded into TDA and, for Trad-TDA, used in engineering applications.

Overall, the results show that using TDA to improve stormwater quality has the potential to help achieve stormwater management goals, while also turning a waste stream into a useful product source to develop cost-effective water treatment technologies.

“TDA that avoids disposal and can be installed as an underground facility can reduce the lifetime costs of the material,” the report said.

Growing Engineering Interest and Support

Recognizing these benefits, engineers are choosing TDA for more applications.  In Wayzata, Minnesota 3600 cubic yards of TDA significantly reduced the lateral load on a commercial wall, leading to a remarkable decrease of over 50 percent in horizontal load.  Engineers used TDA sourced from 170,000 end-of-life tires for use as lightweight fill  to resolve construction issues with unstable soils and stabilize the wall.

The recent completion of the Canterbury Amphitheater Large Stormwater Infiltration Gallery in Shakopee MN showcases the growing recognition of TDA’s engineering value.

Approximately 2.2 million end-of-life tires, incorporating ASTM 6270-B TDA, skillfully crafted by Stantec, the engineering firm, were used to create a stormwater infiltration gallery beneath the amphitheater and parking areas. Engineers chose TDA because of its high void space which allows for efficient water infiltration and storage.

Monte Niemi, President First State Tire Recycling said “This forward-thinking initiative secures the effective management of the venue’s parking lot and rainwater runoff during storm events by employing TDA with its ample void spaces.”

© Scrap Tire News, June 2025