TDA Definition

Tire Derived Aggregate (TDA) refers to recycled tires that have been reduced in size to pieces generally between 12 mm (2 in.) and 305 mm (12 in.) and are intended for use in civil engineering applications.  

The term TDA, therefore, incorporates both “tire chips” and “tire shreds” as identified in ASTM D6270-98 (2004) Standard Practice for Use of Scrap Tires in Civil Engineering Applications.  Under that broadly accepted industry standard “tire chips” are defined as: “Pieces of scrap tires that have a basic geometrical shape and are generally between 12 mm and 50 mm in size and have most of the wire removed.”

Similarly, the standard defines “tire shreds” as “Pieces of scrap tires that have a geometrical shape and are generally between 50 mm and 305 mm in size.”