Highway construction has the potential to make a significant contribution to disposal of the 2 billion to 3 billion scrap tires that are stored or discarded throughout the United States. A recently constructed tire-chip fill in Maine, which was 120 m (400 ft) long, used 200,000 tires. The in-place density of tire chips is less than 50% of that for a typical gravel fill, making them an ideal lightweight fill to stabilize embankments against landslides. In Maine tire chips are being used to construct a bridge-approach fill that is 4.3 m (14 ft) thick to correct stability problems caused by a weak clay foundation. Concerning the effect of a compressible tire-chip layer on pavement life, for two projects in Maine, it was found that placing 1.8 m (6 ft) of soil cover over 0.61 m (2 ft) of maximum-size tire chips yielded tensile strains at the bottom of the test pavement that were the same as for a control section with no tire chips. Even for soil covers as shallow as 0.76 m (2.5 ft), the tensile strains at the bottom of the pavement were only 40% greater than those in the control section. The low unit weight and high permeability of tire chips makes them an attractive retaining-wall backfill. A test wall constructed at the University of Maine showed that the lateral earth pressure at the base of tire-chip fill 4.3 m (14 ft) thick with a 36-kPa (750-psf) surcharge was less than 50% of that for a typical gravel fill. Lower pressures would allow thinner, lower-cost walls to be constructed. These low earth pressures could result in significant cost savings for retaining walls and bridge abutments. Tire chips are also a good thermal insulator to limit frost penetration beneath roads. Their thermal resistance is approximately eight times higher than that of gravel. A test project constructed on a gravel-surfaced road in Maine showed that 0.3 m (1 ft) of tire chips reduced the depth of frost penetration by 40%. Finally, tire chips are inexpensive compared with natural fill materials. Tire chips can typically be purchased for between $2 and $13 per cu m ($1.50 to $10 per cu yd). (Edited Article)


  • English

Media Info

  • Features: Photos;
  • Pagination: p. 17
  • Serial:
    • TR News
    • Issue Number: 184
    • Publisher: Transportation Research Board
    • ISSN: 0738-6826

Subject/Index Terms

Filing Info

  • Accession Number: 00723803
  • Record Type: Publication
  • Files: TRIS, TRB
  • Created Date: Jul 10 1996 12:00AM