Ground Rubber Applications
The market for ground rubber, also referred to as sized-reduced rubber or crumb rubber, has been growing over the past several years. In the ground rubber market there are two classes of particle sizes: ground rubber (10 mesh and smaller) and coarse rubber (larger than 10 mesh, with a maximum size of one-half inch).
Asphalt rubber is the largest single market for ground rubber, consuming an estimated 220 million pounds, or approximately 12 million tires. California and Arizona use the most asphalt rubber in highway construction (over 80% of asphalt rubber utilized). Florida is the next largest user.
Ground tire rubber can be blended with asphalt to beneficially modify the properties of the asphalt in highway construction. Size-reduced scrap tire rubber can be used either as part of the asphalt rubber binder (alao known as, asphalt rubber), seal coat, cap seal spray or joint and crack sealant, or as an aggregate substitution (rubber modified asphalt concrete).
Benefits of using asphalt rubber include:
- Longer lasting road surfaces;
- Reduced road maintenance;
- Cost effectiveness over the long term;
- Lower road noise; and
- Shorter breaking distances.
Asphalt rubber is being used in greater amounts by state Departments of Transportation. Arizona and Florida have been leaders in asphalt rubber utilization. Texas and Nebraska are currently using greater amounts of asphalt rubber. South Carolina is also pursuing utilization of asphalt rubber in county and state roads. Other states that have studied and/or used rubberized asphalt include New York and New Mexico.
For additional information, see:
- Rubberized Asphalt Concrete Technology Center (RACTC)
- Rubber Pavements Association
- US DOT Federal Highway Research Center
- Texas DOT Recycling Program and Texas DOT Specifications for the Use of Recycled Materials
- Florida Study of the Suitability of Ground Rubber Tire as a Parking Lot Surface (45 pp, 7MB, about PDF)
- California Green Roads: Paving the Way With Recycled Tires
Athletic and Recreational Applications
Examples and benefits of using scrap tires in this market segment include:
- Ground cover under playground equipment possesses high impact attenuation/ability to absorb the energy from falling children and objects.
- Running track material increases a tracks resiliency and decreases stress on runners legs.
- Sports and playing fields as a soil additive, increases the resiliency of the field thereby decreasing injuries, improves drainage, and enables better grass root structure.
For Additional Information
Connecticut Department of Environmental Protection: Risk Assessment of Artificial Turf Fields results of a two-year comprehensive evaluation of the health and environmental impacts associated with artificial turf fields containing crumb rubber infill.
A Scoping-Level Field Monitoring Study of Synthetic Turf Fields and Playgrounds (PDF) (123pp, 7.2MB, about PDF) limited EPA study finds low level of concern in samples of recycled tires from ballfield and playground surfaces
- The Use of Recycled Tire Materials on Playgrounds & Artificial Turf Fields fact sheet summarizing the above study
Evaluation of Health Effects of Recycled Waste Tires in Playground and Track Products developed for the California Department of Resources Recycling and Recovery (CalRecycle)
- A Study to Assess Potential Environmental Impacts from the Use of Crumb Rubber as Infill Material in Synthetic Turf Fields (PDF) (29 pp, 83K, about PDF) prepared by the the New York State Department of Environmental Conservation and Department of Health, provides details of the study plan
- Fact Sheet: Crumb-Rubber Infilled Synthetic Turf Athletic Fields
- An Assessment of Chemical Leaching, Releases to Air and Temperature at Crumb-Rubber Infilled Synthetic Turf Fields (PDF) (140 pp, 966K, about PDF) final study
Other uses for ground rubber include:
- Molded rubber products (e.g., carpet underlay, flooring material, dock bumpers, patio decks, railroad crossing blocks, livestock mats, roof walkway pads, rubber tiles and bricks, movable speed bumps).
- New tire manufacturing (up to 10% or higher as per Scrap Tire News ).
- Brake pads and brake shoes.
- Additive to injection molded and extruded plastics.
- Automotive parts.
- Agricultural and horticultural applications/soil amendments.
- Horse arena flooring.