New Outlooks For TDA

Tire derived aggregate (TDA) is a valuable, sustainable resource made from shredded end-of-life tires.  One of the first tire derived materials to earn an ASTM standard, TDA has been used for several decades in various civil engineering applications and since 1992, when the first civil engineering applications using TDA were recognized in the marketplace, the range of uses for TDA has grown. Through education this material has entered the conventional civil engineering world and competes successfully.

Today, in the U.S., TDA is used for bridge abutments, retaining wall backfill, vibration mitigation, long term road repair, earthquake protection, stormwater systems and as fill above and below pipes. Tire derived aggregate has properties engineers need, it’s lightweight, compressible, has good drainage, a higher thermal insulation value and absorbs sound and vibration better than conventional materials.  City and county officials and engineers are taking notice of TDA’s effectiveness when used in these applications.

Research studies, together with information sharing and outreach from the tire manufacturing and recycling industries, academia, engineers, contractors and state and local road agencies are removing barriers and misperceptions about TDA.  A research study for phosphate removal by TDA, biofilm analysis, and stormwater filter underway at the University of Minnesota (see summary this page) has shown positive results so far.

Recent and current TDA projects are producing new methods and ways of using TDA  One is mechanically stabilized TDA walls in which gabion baskets are wired together, filled with rock and anchored to the hillside with layers of plastic grid, tech cloth and TDA.  As areas continue to urbanize, engineers, public works officials and private contractors  are incorporating best management practices (BMPs) in the project design to meet stormwater requirements. TDA drains water really well, creates void space to handle runoff and is low cost, benefits more engineers are choosing in selecting BMPs. How the City of Woodbury Minnesota is using tire derived aggregate for stormwater BMPs is another example of a promising outlook for TDA. In California, L.A. Metro is currently installing TDA for light rail vibration mitigation on a new section of track opening in 2023.

© Scrap Tire News, February 2023