In this Executive Update we highlight Innovations on the Illinois Tollway  based on a conversation with Bill Vavrik, the  NAPA Midyear Meeting , an update on Percent Within Limits and Air Void Regression, and a tour of Permeable Pavements in Dane County.

 Bill Vavrik Q&A: The Illinois Tollway Innovates and Saves

A highlighted speaker at this year's NAPA midyear meeting (read the next article for a meeting overview) was Bill Vavrik with Applied Research Associates, Inc. (ARA), who gave a presentation about technology innovations at the Illinois Tollway. Given the exciting work happening across our southern border, we checked in with Bill for a Q-and-A for this newsletter.

William Vavrik, Ph.D., P.E., is Vice President and Principal Engineer at ARA. He leads a talented team of transportation professionals who are helping customers solve difficult problems in transportation infrastructure. Bill is an engineering leader focused on transportation, infrastructure, asset management, and sustainability.

WAPA: In July you presented at NAPA's midyear meeting about the Illinois Tollway's implementation of innovative processes and technologies for constructing and maintaining pavements. Could you please summarize the most recent findings you discussed?

Bill Vavrik:  Certainly. The Illinois Tollway started its research program in materials in the mid-2000's to help make pavement better -- at lower costs and with equal or improved performance. As a customer-funded organization, the Tollway focuses on high-value research projects with a high likelihood of success and that can be implemented to make a real difference for drivers.

As the Tollway implemented technology innovations, its management and executives sought out a formal quantification of the benefits, asking, "What was the value of the research?" The Tollway and its consultants calculated the cost savings associated with research and innovation, and found that from 2004 to 2015, the Tollway saved $219 million related to aggregate, asphalt and concrete materials.

Steven Gillen, the Tollway's Deputy Program Manager of Materials, wrote an article about this for the Transportation Research Board: "Research Pays Off: Implementing Sustainability Research Saves Illinois Tollway More Than $200 Million." It shows a cost savings of $74 million for asphalt materials between 2007 and 2015 as a result of new innovations. Updated calculations indicate asphalt-related savings to be nearly $100 million through 2016.

What are some of the innovations that are making a difference for asphalt pavements?

Steve's article talks about the testing and expanded use of green technologies: ground tire rubber (GTR), fractionated reclaimed asphalt pavement (FRAP), and recycled asphalt shingles (RAS).

Another key from a design perspective is to avoid over-designing and over-building. The Tollway has worked toward putting the right amount of the right materials into the right part of the pavement.

Hand in hand with that is not prescribing mixes in terms of specific materials. Instead the Tollway leaves it to contractors to select the aggregate, binder and modifiers that will meet stated performance requirements. There are often different but equally valid solutions to achieve rutting or cracking properties or to avoid draindown.

Are there any other emerging asphalt pavement technologies you can tell us about?

Two come to mind. First is dry-process ground tire rubber, where the rubber is added into the asphalt mix at the plant rather than into the asphalt binder at the terminal. This just-in-time use of GTR puts more control into the hands of the asphalt contractor and may end up changing the economies of when and how best to use this modifier. 

Second is a project that the Tollway is doing with the University of Missouri to formalize a performance-related specification for asphalt mix designs. Without a national framework to go on, the Tollway is forging ahead in this area, and hopefully the results will be useful to other agencies as well.

Saving money without sacrificing pavement performance is a common theme here in Wisconsin. Often a road authority will be interested in trying something new but will have concerns about performance. What would you say to them?

"Analysis paralysis" is all too common in transportation research, and sometimes you just have to stop studying and start doing.  Steve Gillen has been instrumental for getting new technologies out into the field as a way to make roads better; I can't credit him enough for his vision and follow-through.

There are ways to be smart about it. Start small, on a shoulder or test section. Rather than using a new mix on a surface course, try it on a less sensitive layer that isn't directly exposed to traffic or weather extremes.

This is how the Illinois Tollway came to be a leader with high-recycled pavements, building pavements with over 50 percent FRAP when other agencies were at the 15 percent range. The Tollway was also an early adopter of stone matrix asphalt (SMA), which has led to an average increase in life of three years, as well as other long-life designs. There's a stretch of perpetual asphalt pavement on I-90 just beyond the Wisconsin border built by Rock Road Companies and William Charles Construction in 2008 and 2009 that is performing beautifully, and it looks like it will perform beyond its originally scheduled mill and fill at 15 years age.

Thanks for sharing this information. We are excited to have you present to our members and customers at WAPA's annual conference in November.

Thank you for inviting me. I look forward to continuing this conversation in Madison.

 NAPA Midyear Meeting

Bill Vavrik's was one of many informative presentations we heard at the NAPA Midyear Meeting, held this July in Chicago. As noted in the Program, other highlights included a presentation by Illinois DOT Secretary Randall Blankenhorn and a full slate of "micro sessions" as in 2016. The half-hour micro sessions featured updates and key takeaways from the NAPA committees, covering such topics as:
  • Advances in Cracking Tests
  • Media Stories, Public Relations, and Outreach
  • Illinois DOT's Implementation of I-FIT
  • Responding to Community Concerns about Asphalt Plant Emissions
  • Silica Rule Update
  • Sustainability's Impact on Industry
The NAPA committees also got down to business at the midyear meeting to advance new and in-progress activities. WAPA Director of Engineering Deb Schwerman and I participate as members or guests on the following NAPA committees:

Brandon Strand's NAPA Committees
  • Pavement Economics
  • Legislative
  • Communications
  • Political Action
  • Go-To-Market Task Group
Deb Schwerman's NAPA Committees
  • Asphalt Research & Technology
  • Engineering Advisory Council
  • Sustainability
  • Environmental
  • Health and Safety

The NAPA committees continue to be actively engaged in addressing a wide range of technical and market issues. We would be happy to answer any questions you may have about what we learned during the committee meetings or presentations.


 Engineering Update: Percent Within Limits, Air Void Regression

Percent Within Limits

In last October's newsletter we wrote about Percent Within Limits (PWL), a statistics-based acceptance method for asphalt pavement projects, as well as three PWL pilot projects for 2016.

2017 represents year two of the pilot program, which has grown significantly in scale. This year there are 18 pilot projects across all five WisDOT regions (and kudos to Northeast Region, home to about half of these).

WAPA has been following this work closely, and b ased on site visits and discussions with WisDOT staff and asphalt contractors alike, we are pleased to report that PWL is moving Wisconsin in the right direction.

As expected, the special provisions of PWL are meeting the goals promoting uniformity of materials for larger projects and ensuring that asphalt production and placement meet specifications consistently day after day.  Public and private partners involved in using PWL continue to fine-tune the process, helping to make it more user-friendly and able to capture the information needed in the most straightforward manner possible.

We will continue to report as PWL makes its way into regular practice for appropriate-sized asphalt pavement projects in Wisconsin.

Air Void Regression

Last summer we also reported on a federal Asphalt Pavement Density Project that gave WisDOT a chance to test a number of variables to increase in-place density as a means of improving durability. Noteworthy among the different approaches was the use of air void regression, a controlled process of adding virgin PG binder to an asphalt mix to reduce air voids by one percent during production.

That project, together with national research, helped validate the direction that WisDOT and Wisconsin's asphalt industry were already heading toward increased density in asphalt pavements. 

The state's special provisions for 2017 call for the density of all asphalt pavements -- from roadways to shoulders -- to be raised by 1 to 1  percent, and these requirements will appear in WisDOT's standard specification starting in 2018.

Air void regression, together with other construction techniques for improved density, will help contractors build longer-lasting asphalt pavements that Wisconsin motorists can count on.

 Permeable Pavement Tour of Dane County

WAPA took part in a June 27 tour of permeable (or porous) pavements across Dane County. The event was co-hosted by Dane County's Land and Water Resources Department and the U.S. Geological Survey (USGS) and featured asphalt, concrete, and paver technologies. When properly installed and maintained, they can help manage stormwater and filter runoff back to the aquifer.

Porous asphalt pavements on tour included the  City of Fitchburg Library, Stricker Park in Middleton, local businesses, two car dealerships, walkways, and a bike path. A highlight of the day was the p ermeable pavement test site on Sycamore Avenue in Madison. Here a USGS study is seeking to measure the performance of several types of permeable technologies. Side-by-side plots are instrumented to measure reductions in runoff volume and pollutants.

The tour was a very informative look into work being done locally around Madison, and many of the attendees from government and industry were interested in the progress that these types of pavements have made over the last decade.

What has remained constant with porous pavement is the need to match the proper mix design with the proper application -- and then to commit to proper long-term maintenance. All these components are necessary for a successful deployment.

Fortunately, WAPA offers helpful Technical Guidance on Porous Asphalt Pavements, which addresses design, construction and maintenance in detail.  Helpful as well are advances in maintenance equipment. For example, a riding sweeper only 4  feet wide is now available, making it easier than ever to keep pavement pores free of debris on paths and parking lots.

WAPA is always happy to answer questions and help pavement owners learn if a porous pavement is a good fit for their needs.

 Up Next for 2017

As previously mentioned, WAPA is at work on an  asphalt parking lot design guide . It will build on guidance currently available from Asphalt Pavement Alliance and WAPA, serving as a comprehensive tool for the design, construction, and maintenance of asphalt pavement parking lots. Please look for details in the coming months.

Also, as a reminder, save the date for the WAPA conference.

November 28-29, 2017
Madison Marriott West

Registration will open in early fall, and we look forward to seeing you in Madison.

As always, if you have any questions about this information or if we can be of assistance in any other way, please don't hesitate to contact us.
Thanks and On Wisconsin!