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Pooled Fund Partners

Institute for Transportation

Institute for Transportation
2711 South Loop Dr, Suite 4700
Ames, IA 50010-8664

Phone: 515-294-8103
Fax: 515-294-0467
E-mail: InTrans Communications

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Iowa

Iowa

The Iowa Department of Transportation (Iowa DOT) joined TPF-5(213) as a state partner in 2009. Iowa DOT began their research in the use of recycled asphalt shingles (RAS) in 1997. The Iowa DOT in partnership with Benton County conducted a demonstration project utilizing post-consumer RAS for dust control on a secondary road in Benton County. However, the market development of RAS did not move forward as the technology for processing RAS was not well developed.

In 2009, the Iowa DOT began working closely with Iowa State University (ISU), the principle investigator, to develop a specification for RAS in HMA. The Asphalt Pavement Association of Iowa (APAI) and the Iowa Department of Natural Resources (Iowa DNR) also worked closely with the Iowa DOT and ISU to promote the market development of RAS. In 2009, two demonstration projects were completed using post-consumer RAS in HMA and warm mix asphalt (WMA) applications. In January 2010, the DOT released a developmental specification for RAS (DS 09035), which has been updated with the newest ( Developmental RAS Specifications DS09059))(DS 09059) posted on December 21, 2010. The developmental specification allows up to 5 percent post-consumer or post-manufactured RAS with 100 percent passing the 3/8-inch sieve and 95 percent passing the #4 sieve and not more than 1.5 percent deleterious material.

Iowa DOT goals for the study are in researching the use of different RAS percentages in HMA applications; determining the available RAS asphalt cement (AC) content; and to enhance the research of the pooled fund study by completing parallel demonstration projects using RAS in WMA applications and working with ISU to complete additional research.

Iowa DOT completed their demonstration project in June/July 2010, on Highway 10 in Sioux County located in Northwest Iowa. The demonstration project consisted of three test sections with mixes utilizing 4 percent, 5 percent, and 6 percent RAS only (no recycled asphalt pavement [RAP]) and a control section with no recycled product (no RAS or RAP).

Two additional projects utilizing post-consumer RAS were completed in 2010 by the Iowa DOT in parallel with the TPF-5(213) demonstration project. The first project was completed in June 2010, in Mahaska County on Highway 63 in Southeastern Iowa. The HMA project included two test sections and a control section. One test section included 13 percent RAP and 5 percent RAS and the second test section included 11 percent RAP and 5 percent RAS. The control section included 20 percent RAP only. A second project was completed in October 2010, on Highway 61 in Southeastern Iowa. The WMA project included two test sections one utilizing 13 percent RAP and 5 percent RAS and a second section utilizing 6 percent RAP and 7 percent RAS. The control section included 20 percent RAP only.

Iowa DOT Partner:

Scott Schram, P.E, PhD

Phone: (505) 239-1604

E-mail: Scott.Schram@dot.iowa.gov

Blog

IaDOT Tech Brief

The technical brief summarizes the results of Iowa DOT's demonstration project completed for TPF-5(213).  The final report can be found under the Project Reports Section.

Additional Post-consumer RAS projects completed in 2010

Two additional projects utilizing post-consumer RAS were completed in 2010 by the Iowa DOT in parallel with TPF-5(213) demonstration project.

The first project was completed in June 2010, in Mahaska County on Highway 63 in Southeastern Iowa.  The HMA project included two test sections and a control section.  One test section included 13%RAP and 5%RAS and the second test section included 11%RAP and 5%RAS.  The control section included 20%RAP only.

A second project was completed in October 2010, on Highway 61 in Southeastern Iowa.  The WMA project included two test sections one utilizing 13% RAP and 5%RAS and a second section utilizing 6%RAP and 7%RAS.  The control section included 20%RAP only.