Recycled Asphalt Shingles (RAS) paving 

Asphalt Shingle Recycling - Roofs to Roads Project

As of 2012, recycling opportunities may not exist for a number of years. There is a large stockpile of asphalt shingles available at the asphalt manufacturing facilities. Acceptance of shingles has been significantly curtailed. Roofers should contact the asphalt manufacturers for current policies regarding shingle recycling.

For more information about this project, contact Resource Conservation at 720-564-2220.

Timeline and Reports

Benefits of Using Recycled Shingles

  • Reduces waste to landfills. Approximately 250,000 tons of shingles enter Colorado’s landfills every year. Shingles take decades to decompose, create caps in landfills allowing methane gas to develop, and don’t compact well.
  • Avoid Greenhouse Gas emissions. A life-cycle analysis of asphalt pavement (Environmental Road of the Future, COLAS group, September 2002) indicates 27,000 pounds of carbon dioxide are avoided on a typical paving project, by using 5 percent shingles in place of virgin asphalt binder.
  • Improved road performance. Studies and performance tests show that use of shingles in asphalt mixes helps reduce ruts and cracks.

Using Recycled Asphalt Shingles in Asphalt Pavements and Creating Specifications Allowing Shingles

The following information offers a summary of some of the 20 years of research on the use of recycled shingle material in asphalt mixes and pavements. Additional technical reports can be found on the national website at shinglerecycling.org, managed by the Construction Materials Recycling Association, and on Roofs2RoadsColorado.

  • Missouri Department of Transportation supports shingle recycling and re-use as road paving material.
  • Environmentally Friendly Policy for the Missouri Department of Transportation (MoDOT). Scroll down to Recycling, then to Roofs to Roads, to learn more about Missouri's shingle recycling efforts, including their cost savings.
  • Missouri DOT Special Provisions (48KB). A shingle specification for a typical paving project.
  • Missouri Specification (211KB), Section 403.2.6.2 MoDOT Asphalt Specification, Section 403. See RAS spec, 403.2.6.2, on page 3.
  • MoDOT Specs (842KB), a PowerPoint presentation by Joe Schroer, PE, of MoDOT, reviewing the development of MoDOT's shingle specification and other national guidelines.
  • Let Me Shingle Your Roadway (477KB) - Interim report for Iowa DOT Research Project HR-2079, by Vernon J. Marks (Iowa DOT) and Gerald Petermeier (Benton County Engineer). Performance evaluation of asphalt pavements that include shingles.
  • Roofing Shingles and Toner in Asphalt Pavements (1MB) - Report by Texas Transportation Institute, sponsored by the Texas Department of Transportation. Laboratory testing of HMA mixtures containing shingles (Hveem stability, indirect tension, resilient modulus at several temperature, moisture susceptibility, TxDOT static creep, air void content, and voids in the mineral aggregate) were performed; findings indicate that roofing waste is a viable waste stream that has utility in HMA.
  • Virginia Transportation Research Council Research Report (742KB): Use of Manufactured Waste Shingles in a Hot-Mix Asphalt Field Project in 2006, a contractor requested that the manufactured waste shingles be allowed on an overlay paving project in southeast Virginia. The 4.1 mile two-lane section was paved using a surface mix containing 5 percent shingle waste and a surface mix contain 10 percent recycled asphalt pavement for comparison. Density tests were performed on the pavement, and various laboratory tests such as permeability, fatigue, tensile strength ratio, rut, and binder recoveries were performed on samples of mix collected during the construction of the section. Both the field and laboratory test results indicate that the behavior and performance of the two mixes should be similar.
  • Who Thought Recycled Asphalt Shingles (RAS) Needed to be Landfilled (95KB): Why Not Build a Road? Paper prepared for Presentation at the Recycled Materials and Recycling Processes for Sustainable Infrastructure Session of the 2008 Annual Conference of the Transporation Association of Canada - Toronto, Canada. A laboratory study was performed investigating the use of RAS in a HL8 base course mix. Five asphalt pavement mix designs were considered. To compare the various mix designs, the dynamic modulus test, resilient modulus test, Thermal Stress Restrained Specimen Tensile Strength Test (TSRST), and French wheel rutting test were run for all five mix designs. Mixes with a percentage of shingles were found to have the lowest susceptibility to rutting (less than 4 percent), and the most resistance to thermal checking.

Contacts

Roofs to Roads Project

720-564-2220
720-564-2227 (fax)
Resource Conservation Division

Boulder

Boulder County Recycling Center
1901 63rd St.
Hours: 8 a.m.-4:30 p.m. M-F
Map and directions

Mailing Address

1901 63rd St.
Boulder, CO 80301

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