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A NEWSLETTER TO EXPAND MARKETS FOR RECYCLED MATERIALS


Fall 2011


Washington State to Allow Recycled Asphalt Shingles in Paving on Select Projects in 2012

Road paved with RAS

King County demonstration road is paved with RAS.

The Washington State Department of Transportation (WSDOT) is close to completing a special provision that will allow paving contractors to use recycled asphalt shingles (RAS) in select state hot mix asphalt (HMA) paving projects in 2012.

Washington's current HMA paving specification allows contractors to use up to 20 percent reclaimed asphalt pavement (RAP), which is derived from old paving surfaces, in newly paved projects. The new special provision will allow contractors to increase the amount of RAP and/or use RAS in HMA on select paving projects next year. WSDOT will closely monitor the design, construction and performance of these projects to determine if increased RAP and RAS will become a standard practice in the state highway construction program. Currently, 26 states allow RAS in HMA paving mixes (see sidebar).

HMA is made up of coarse and fine mineral aggregate and liquid asphalt, which serves as the binder or glue in the mix. Asphalt shingles consist of these same basic ingredients, with asphalt contents ranging from 20-30 percent, depending on age and other factors. Reclaiming the asphalt from shingles offers a cost-effective alternative to virgin asphalt and aggregate used in paving mixes.

WSDOT's RAP/RAS special provision will cap the maximum total recycled binder replacement (i.e. asphalt from RAP and RAS to replace virgin asphalt) at 40 percent and will limit the use of RAS to 5 percent of the total weight of the mix. According to several local HMA producers, the use of RAS in HMA may reduce overall paving costs by as much as $5 per ton, depending on virgin material costs. If a paving contractor elects to use high RAP or RAS, they will need to perform additional preliminary materials testing, develop the HMA mix design and construct a paving test section to ensure specification conformance prior to production paving.

Closeup of road is paved with RAS

The special provision is the outcome of a joint effort between WSDOT and the Washington Asphalt Paving Association (WAPA), the industry group dedicated to furthering the use and quality of HMA pavements. The two organizations have a longstanding history of collaborating to improve asphalt pavement performance.

“This is a WSDOT special provision but it was truly an industry-led effort,” said Joe DeVol, Bituminous Engineer for WSDOT State Materials Lab and co-chair of the effort. “The use of higher quantities of RAP and RAS in HMA has to deliver an equal or superior quality product and has to make economic sense to the industry. WAPA came to us with a proposal and we worked with them to put in place the standards and tests needed to ensure performance.”

To develop the specifications for using additional RAS and RAP, a technical RAP/RAS subcommittee was formed, comprised of representatives from WSDOT, the Federal Highway Administration, US Oil, and WAPA. Subcommittee co-chair Mike Costello (Granite Construction, representing WAPA) said, “It has been a great process. Our industry wants to be green but also wants to do it right. The focus all along has been on quality, consistency, and performance. I feel confident that our work will benefit the industry financially, use more recycled material, and deliver a high quality product.”

The absence of a state specification that allows RAS in paving has been a significant barrier to recycling asphalt shingles from re-roofing projects locally. With some 27,000 tons of asphalt shingles generated in King County annually, HMA paving is considered the highest and best end use for this material.

LinkUp has been working closely with WSDOT, King County Department of Transportation — Road Services Division, the paving industry, and other stakeholders to test the use of shingles in paving including completing a successful paving demonstration in South King County to document the performance of a roadway paved with RAS. Learn more about the Shingles in Paving Project Demonstration.






King County focus

King County Focus: King County Council approves new solid waste rate
The Metropolitan King County Council has approved a one-year solid waste disposal rate for 2012. The disposal rate will increase from $95 to $109 per ton to support King County's program to modernize its 50-year-old solid waste handling system, while giving cities and the County time to consider an extension of their long-term agreements in order to save ratepayers money on the cost of financing those improvements.

In general, as solid waste rates rise, people and businesses are more likely to look for ways to reduce waste and recycle more so they can switch to a smaller, less expensive garbage can. With this rate increase, the average residential customer who puts out one can for curbside collection will see an increase of about 82 cents per month in their garbage bill. The rate increase includes funds to pay for upgraded transfer stations with space to recycle new materials. Read more about the new rates online.

Transfer Operator helping customer

Transfer Station Operator assists self-haul customer at the Shoreline Recycling and Transfer Station.






Fast facts

States Allowing the Use of Recycled Asphalt Shingles in Asphalt Paving

Map of US

Overall, recycled asphalt shingle (RAS) use increased 57 percent from 2009 to 2010.

In the past four years, approximately 10 additional states and the Illinois Tollway adopted new RAS specifications or amended their older specs to allow RAS derived from tear-off shingles. These specs may be “special provisions,” meaning that they are allowed on a job-by-job basis. The 10 states are: Colorado, Illinois, Indiana, Iowa, Kansas, Minnesota, Missouri, Oregon, Texas and Wisconsin.

Transportation departments in California and Washington have RAS specs in draft or in progress. There are now a total of 26 state transportation departments with RAS specs:

  • Nineteen allow tear-off and manufacturer scrap
  • Seven allow manufacturer scrap only


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