Welcome from WisDOT’s Peg Lafky

As a program and planning analyst for the WisDOT Research and Library Unit, my responsibilities include the Wisconsin Highway Research Program. I work closely with WHRP staff to continually improve processes and find better ways of doing business. Recent efforts include revision of the proposal evaluation process used to select WHRP investigators. 

WHRP modified the proposal evaluation process to integrate statewide vendor selection practices into WHRP procedures. Working with the Technical Oversight Committee chairs, we developed selection criteria using a weighted scoring method. Scoring items include the proposer’s understanding of the problem, the research approach, experience, familiarity with WisDOT practices, labor costs and other considerations. WHRP used the new process for selecting investigators for the 2009 projects, first on a trial basis with the Data Integration TOC, and then, after receiving feedback and refining the process, with the remaining four TOCs.

We surveyed TOC members after selection was completed; responses indicated broad support for the changes to the proposal evaluation process. We will continue to make improvements to this and other WHRP processes as needed. Currently we are working on RFP templates, proposal preparation guidelines and TOC review instructions to enhance the selection process for 2010.

One thing I’ve taken away from this experience is the commitment of everyone involved with WHRP. We are fortunate to have so many dedicated people working together in this program from WisDOT, academia and industry.  

One last note: Nikki Hatch has left her position at WisDOT for a position in the newly formed Wisconsin Department of Children and Families. We are fortunate, however, that a new section chief has been named. Daniel Yeh, most recently a policy initiatives advisor here at WisDOT and formerly with the Office of Public Affairs and Division of Transportation Investment Management, assumed his new duties on October 27. Welcome Daniel!

Peg Lafky, Program and Planning Analyst
WisDOT Research and Library Unit
marguerite.lafky@dot.state.wi.us
(608) 266-3663

Highlights from WHRP Steering Committee

The Steering Committee met at Hill Farms on Friday, September 19, for an update on WHRP program activities. The committee discussed and provided comments on the proposed new investigator selection process and asked that the final procedure be presented for approval at the next meeting, so the new selection criteria would be in place for FFY 2010 proposals in the spring. The group also provided comments on the draft Steering Committee Bylaws, which will now be finalized and incorporated into the WHRP Procedures Manual.

Hussain Bahia and Andrew Hanz presented a comprehensive review of the outcomes of all completed WHRP research projects from 1998 through 2008. The review, carried out in cooperation with the TOC chairs, showed an “implemented” rate of from 15 to 55% for the four TOCs. While many state research programs do not compile data on implementation rates, reports of 10 to 20% implemented are typical, indicating that Wisconsin is doing well.

It’s important to follow up on completed projects to either implement them or determine that they are not suitable for implementation. In the future, TOCs will be asked to provide justification for funding a new research project rather than funding implementation efforts on already completed projects.

Finally, the Steering Committee approved a new TOC membership policy aimed at including additional stakeholders, improving attendance and rotating TOC chair positions. The next meeting of the Steering Committee will be December or January.

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Summer Field Research

WHRP investigators work alongside road construction crews when research studies require field research. Sampling, testing and studying construction techniques provides the critical field information investigators need in their research. Highlights from this summer include these projects:

• Hani Titi of UW-Milwaukee led a group of researchers to several sites around the state to investigate the condition of various asphalt overlays. This project will recommend improved ways to treat or repair existing pavements prior to laying a new flexible layer. For information, see the Web page for project 0092-08-09.

• Sam Helwany of UW-Milwaukee examined sites at the Marquette Interchange for his work on two WHRP projects. One is analyzing an innovative design for post-and-panel retaining wall foundations, and the Interchange site offered an opportunity to evaluate soil conditions in which such a design would be installed; see the post-and-panel project Web page. The other project required analysis of how pile-driving vibrations spread in an area and what impact the vibrations have on fresh concrete poured nearby. See further information on the Web page for project 0092-06-04.

• Another important WHRP project is evaluating ways to prevent spalling of bridge concrete components by protecting rebar from corrosion. Researchers on this project took cores this summer from bridges in Pierce County and Dodge County to supplement the extensive experimental work they are doing. See the Web page for project 0092-06-06.

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Project status at a glance

As of June 30, 2008, there were 39 active WHRP projects. Four projects were completed during the last quarter.

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Research in Focus

Preventing Corrosion in Steel-Reinforced Columns
0092-07-07, Evaluation of Fiberglass Wrapped Concrete Bridge Columns

Some concrete columns in Wisconsin bridges built before 1980 are reinforced with steel bars. These bars are susceptible to corrosion, which is accelerated by chlorine-rich deicing solutions used during the winter driving season. Corrosion causes these bars to expand, leading to damaged concrete and a loss of column structural integrity.

To address this problem, WisDOT’s current maintenance policy is to patch damaged areas and wrap columns with a thin layer of a fiberglass composite material, which provides a barrier to moisture and deicing salts.

But the premature failure of some of these wraps has raised questions regarding their effectiveness. Professor Dante Fratta and a team of researchers at the UW-Madison were awarded a WHRP project to assess the causes of this continuing corrosion by performing tests on heavily damaged columns.

Preliminary results show that once columns have been exposed to chlorine in road salts, chlorine ions continue to cause corrosion in columns even after wraps have been applied. Investigators also found that some wraps do not extend far enough below the surface of the soil surrounding the column, allowing deicing solutions to migrate through the soil into the column.

A final report to be published later this year will contain recommendations, including: extracting chlorine before applying wraps, reducing the salt concentration of deicing solutions, and extending wraps farther beneath the soil.

For details, see the WHRP study’s project page or contact Travis McDaniel, chair of WHRP Committee of Technical Oversight, at (608) 266-5097.

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Integrating WisDOT Pavement Databases to Facilitate Research and Improve Performance Models
0092-08-17, Development of a Database Framework and Implementation Plan for Integrating WisDOT Materials and Construction Databases

Currently WisDOT’s pavement performance, materials and construction data are all housed in independent databases maintained by different working groups within the department.

The lack of integration of these databases makes it difficult for researchers working for WisDOT to examine relationships between field performance and material properties measured in the laboratory. Investigators often must search several databases for desired information about a specific section of pavement, leading to significant delays in the research.

Through a recent project of WHRP’s Data Integration Technical Oversight Committee, Kelly Smith of Applied Research Associates, Inc. is leading a research team to develop recommendations for integrating these databases through a common referencing system. Several alternatives will be proposed along with a cost-benefit analysis for each.

One possibility involves using the Location Control Management database maintained by WisDOT’s IT Strategy & Architecture Section. LCM was developed to address the need for integrating data from different sources. It provides a foundation for accessing data from several different WisDOT databases for a single location on the pavement network.

Achieving this integration is particularly important in light of the department’s planned implementation of the Mechanistic Empirical Pavement Design Guide, an AASHTO guide that will change the fundamental criteria for pavement design. Implementing MEPDG will require detailed historical construction and performance data in order to calibrate national performance models to Wisconsin weather conditions and local road construction materials.

For details, see the WHRP project page or contact John Cherney, chair of the Data Integration Technical Oversight Committee, at (608) 264-8142.

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Regional and National Collaboration

North Central Pavement Hosts Stabilization Workshop in Madison

The North Central Pavement Research and Implementation Coordination Partnership hosted a workshop on October 8 and 9 in Madison on design and construction guidance for stabilization of underlying pavement layers. The workshop focused on stiffness and other pertinent design characteristics of bases and subbases, the use of recycled asphalt pavement and geosynthetics, and other technologies for achieving optimal stiffness to support various pavement designs.

Attendees at the workshop, in addition to WHRP, included representatives from Wisconsin DOT, Michigan DOT, Minnesota DOT, and the Canadian provinces of Manitoba and Ontario (by Web conference). For further information and to view the following workshop presentations, please visit the study Web site:

• WisDOT's Policy for Use of Select Materials in Subgrades

• Application of Laboratory Evaluation to Develop Stiffness Values and Layer Coefficients for Design

• Guidelines and Best Practices for Selecting the Proper Subgrade/Base Stabilization Alternative

• Construction Quality Control Practices for Evaluation of In-situ Stiffness and Material Variability

• Performance of Michigan's Stabilized Base Projects

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Modified Asphalt Research Center—MARC

Researchers at UW-Madison’s Modified Asphalt Research Center continue to address critical needs related to modified asphalts. These advances have generated significant interest in recent months:

• Recycled Asphalt Pavements. Asphalt pavements must be recycled with care because the properties of the asphalt binder change with age. MARC researchers have developed a protocol to estimate the low-temperature rheological properties of binders in the RAP without the damaging effects of solvent extractions. The results so far are encouraging: The new procedure captures the effect of aged properties of asphalt binder in the RAP and can also estimate the low temperature PG grade of the blended binder.
  

• Foamed Asphalt. Foamed asphalt is a relatively new process in the United States by which moisture is injected into hot paving-grade asphalt binder, giving the asphalt a low-viscosity, foam-like consistency suitable for coating aggregates at lower temperatures. Foamed asphalt has several potential benefits, including reduced energy requirements due to lower production temperatures and as a method to mix asphalt with cold and damp aggregates for applications in partial and full depth recycling projects.
  
  MARC researchers recently acquired a specialized device for foaming asphalt in the lab, the Wirtgen WLB10. Professor Kim Jenkins and student Andre Greyling, both from the University of Stellenbosch, South Africa, recently visited UW-Madison to shared their experience with this equipment. They will collaborate with UW-Madison on an ongoing basis on cold mix asphalt emulsion applications.

For more information on these or other MARC research projects, contact Hussain Bahia.

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WHRP at the Mid-Continent Transportation Research Forum

WHRP investigators presented recent findings at this year’s Mid-Continent Transportation Research Forum, held in Madison August 14-15. Sponsored by several university organizations and the departments of transportation in Wisconsin and Iowa, the forum showcases applied research of benefit to transportation practitioners.
In the asphalt materials track of the forum, WHRP’s Hussain Bahia and Andrew Hanz teamed with Kim Jenkins of the University of Stellenbosch in South Africa to present a recommended framework for “Performance Grading of Bitumen Emulsions for Sprayed Seals.”

The investigators identified chip seals, micro surfacing/slurry seals and fog seals as emulsion types that could benefit from systematic grading using existing and recently developed laboratory tests. They proposed specific tests for measuring initial stability, breaking rate, sprayability and wetting properties of emulsified bitumen. They also proposed tests of residual bitumen that address in-service performance with respect to: early aggregate loss, long-term raveling, fatigue cracking and thermal cracking.

For more information on this framework for performance grading, see the authors’ presentation or contact Hussain Bahia.

Other presentations related to WHRP at the Mid-Continent Forum included:

• “Marquette Interchange Instrumentation Project,” Leonard Makowski, Flex TOC chair. Related to WHRP project 0092-06-01.

• “Factors affecting Initial Roughness of Asphalt Pavements in Wisconsin,” Haifang Wen, former Flex TOC member.

• “A New Test Method for Determining Asphalt Binder Fatigue Resistance,” Carl M. Johnson, WHRP staff and Flex TOC member.

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Outreach

Flexible Pavement Research Needs Survey

The Flexible Pavement Research Needs Survey was developed last year by WHRP Program Manager Andrew Hanz to identify issues that need research. The survey asked WisDOT engineers and partners to review design guidance in Wisconsin’s standard specifications, facilities development manual, and construction materials manual. Respondents reviewed these documents and then made suggestions for changes or identified research needs for each guideline or specification they thought required attention.

Respondents from WisDOT, contractors and consulting firms identified five areas of common concern, including:

• Cold weather paving

• Replacement of nuclear density testing

• Mix design to increase skid resistance and spray reduction

• Higher use of recycled asphalt pavement and recycled asphalt shingles in HMA

For more information on the survey and its findings, contact Andrew Hanz.

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WHRP Participates in Asphalt Expert Task Groups

WHRP members are active contributors to a number of FHWA Expert Task Groups on asphalt. Participants in ETGs this summer included Judie Ryan of WisDOT, Erv Dukatz of Mathy Construction Co., and Hussain Bahia, Andrew Hanz and Carl Johnson of UW-Madison.

At its June meeting, the Modeling ETG discussed several NCHRP projects in detail: 9-30A, 1-41, and 1-42A. The ETG also addressed modeling efforts related to accumulated fatigue damage in asphalt binders and mixtures. More information can be found at the ETG’s Web page.

The Mixtures ETG has provided oversight to numerous completed research efforts related to improved mix design and quality control that are ready for implementation. These efforts include guidelines for improved mixture design procedures, quality control measures to ensure repeatable Superpave Gyratory Compactor measurements, and recommendations for field and laboratory measurements of aggregate and hot mix specific gravities. For more information on this ETG, contact Andrew Hanz.

This summer the Binder ETG discussed promising new tests under development at UW-Madison. The multiple stress creep and recovery test may replace the parameter G*/sin (δ) in defining the high temperature grade in the PG binder system, and the binder monotonic test may similarly replace the parameter G* sin (δ) used for binder fatigue testing. For more information on these research efforts, contact Carl Johnson.

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Implementation Report

Determining the strength of alternative working platforms
0092-06-08, Implementation of Equivalency of Alternative Working Platforms and Their Pavement Design Strength Contribution

WisDOT uses granular materials, including industrial byproducts and geosynthetics, to strengthen subgrades below the pavement base course.

Four recent WHRP reports (0092-45-15, 0092-45-18, 0092-00-12, and 0092-03-12) show that these subgrade enhancement and reinforcement methods (such as pit run sand and gravel, fly ash and breaker run stone) offer not just stable working platforms for construction crews, but also structural benefits to pavement structures placed above these subgrades.

Professor Tuncer Edil of UW-Madison is leading an implementation of this research to determine standardized thicknesses for eight of these subgrade improvement materials. These standardized material values will allow WisDOT to reduce on-site testing and optimize the strength contribution of each material type.

A recent evaluation of material sections using computer modeling and vertical load laboratory tests shows that recommended thicknesses perform very close to estimates. Once this project is wrapped up the final recommendations will be proposed for inclusion in WisDOT’s Facilities Development Manual.

For details, see the WHRP implementation’s project page or contact Bob Arndorfer, chair of the Geotechnics Technical Oversight Committee, at (608) 246-7940.

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About WHRP
www.whrp.org

The Wisconsin Highway Research Program was established in 1998 by the Wisconsin Department of Transportation to conduct research on highway materials and construction methods. WHRP is administered by the UW-Madison Department of Civil and Environmental Engineering. A Steering Committee chaired by the WisDOT Research Administrator provides policy direction to the WHRP Technical Director, Program Manager and five Technical Oversight Committees chaired by WisDOT engineers. The TOCs focus their work on Flexible Pavements, Rigid Pavements, Geotechnics, Structures and Data Integration. The Steering Committee and TOCs are composed of representatives from WisDOT, FHWA, academia and industry.

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