Welcome from Flexible Pavements TOC Chair

Welcome to Issue 7 of WHRP E-News, our quarterly update of the work we’ve been doing in the Wisconsin Highway Research Program.

A Wisconsin winter like we’ve just had reminds us why we need research. These cycles of freezing and thawing have taxed our snow crews for months, and they will challenge repair crews for several more. Pavements and structures have suffered more this year than normal from expansion and contraction, scraping by snowplows, bruising by skidding traffic, and chemical assault from road deicers.

Research helps us build, repair and maintain roads that are better able to handle the severe weather. This month the WHRP Technical Oversight Committees are carefully reviewing investigator proposals for the FFY 2009 projects. These research projects, detailed below, will address issues such as drainage in base courses and fatigue risks in signage.

In coming weeks field work will begin on our evaluation of intelligent compaction. This research, a joint effort of the Flexible Pavements and Geotechnics TOCs, examines the merits of this promising new technology for measuring density during compaction of Wisconsin subgrades, bases and asphalt pavements.

Investigators will also finish analysis and calibration of the new Mechanistic-Empirical Pavement Design Guide inputs used in the Marquette Interchange deep-strength pavement project, which was instrumented with gauges and sensors in 2005.

It will be a busy spring for WisDOT and for WHRP.

Leonard Makowski
Engineering Services Supervisor
WisDOT Southeast Region
Chair, Flexible Pavements TOC
leonard.makowski@dot.state.wi.us
(262) 548-5618

TOCs Begin Weighing Proposals for FFY09 Research

The TOCs for pavements, structures and geotechnics have begun reviewing project proposals received from investigators responding to the FFY 2009 Requests for Proposals. The 2009 research topics were approved by the Steering Committee in December, and proposals were due in late February.

Nine new research topics were approved:

Flexible Pavements TOC

• Evaluation of asphalt mixtures based on Flow Number

• Performance of tack coats

Geotechnics TOC

• Evaluation of cast-in-place piling

• Evaluation of foundation movements

Rigid Pavements TOC

• Open-graded base course performance

• Fly ash replacement levels and performance

• Modulus of elasticity as an MEPDG input

Structures TOC

• Bridge integrated analysis

• Concrete cracking in new decks and overlays

Other projects were extended or funded for another research phase, including work on fine coatings of aggregates and sign support fatigue. The Rigid Pavements TOC also drew from FFY 2009 funds to support three pooled fund projects.

Review the RFPs and related literature searches on the WHRP Web site. For more information, contact WHRP Program Manager Andrew Hanz.

Return to Table of Contents

Steering Committee Establishes New Policies, Approves FFY09 Project Requests

The WHRP Steering Committee met December 11 in Madison to consider new projects and policies.

The committee took action on several items at the meeting. Committee members:

• Approved 14 funding recommendations by the TOCs, including nine new projects

• Set timelines for FFY09 project proposal review, including April 4 for proposal selection by the TOCs and April 11 for presentation to the Steering Committee for approval

• Approved refinements to the implementation project process

• Established a new time extension policy

• Established new vendor selection procedures and proposal guidelines

Review the meeting minutes or contact Andrew Hanz.

Return to Table of Contents

WHRP, WisDOT and MRUTC Working Toward MEPDG Implementation

WisDOT continues to work toward adoption of the new AASHTO Mechanistic-Empirical Pavement Design Guide, gathering new data, validating research recommendations and calibrating inputs.

WHRP recently produced a report detailing the projects completed or in progress that will help WisDOT with implementing the MEPDG.

The report includes WHRP studies and other projects that WisDOT helps fund, including Midwest Regional University Transportation research and pooled fund commitments. In the last several years WHRP has undertaken 15 studies and other projects addressing various aspects of MEPDG implementation including eight by the Flexible Pavement TOC, five by the Geotechnical TOC, one by the Rigid Pavement TOC, and one general pavement study. In addition, WisDOT has participated in two pooled fund projects with other states relating to MEPDG, and helped fund three studies undertaken by the Midwest Regional University Transportation Center.

Return to Table of Contents

New Face Coordinating WHRP Meetings, Assisting with Activities

Since January, WHRP has enjoyed the help of Gabrielle Rochester, Group Coordinator with CTC & Associates LLC.

Gabrielle is working with WHRP to coordinate meetings and minutes, follow-up on conference initiatives, and assist with organizational planning. Gabrielle will also help WHRP manage its activities and communications with the University of Wisconsin civil engineering group, the Asphalt Research Consortium, and the Modified Asphalt Research Center. Contact Gabrielle at grochester@wisc.edu or (608) 576-7199.

Previously, Gabrielle gained extensive management and organizational experience in retail management positions, most recently as general manager of the Gap’s Michigan Avenue store in Chicago. Gabrielle lives in Madison with her husband and two children.

Welcome, Gabrielle. We’re excited to have you with us.

Return to Table of Contents

Project Status at a Glance

As of December 31, 2007, there were 31 active WHRP projects. Six projects were completed during the last quarter.

Return to Table of Contents

Research in Focus

Data Integration TOC Seeks to Expand Uses of Pavement Data
0092-08-16, Evaluation and Recommendations for Further Development of the WisDOT Pavement Information Files (PIF) Database

WHRP’s newest TOC, Data Integration, manages research aimed at tying together various data banks to optimize their use and applications. One of the most valuable sets of data WisDOT gathers is for its Pavement Information Files database. This collection of ride and distress data is maintained by WisDOT’s Pavement Data Unit. The PIF database tracks ride quality of state roads as well as details on damage and distress.

This information is used to identify repair and rehabilitation needs across Wisconsin, but it may also be useful for tracking performance of various pavement designs and materials. This could inform design decisions related to adoption of the new Mechanistic-Empirical Pavement Design Guide, make follow-up research on pilot sections easier, and influence planning and other management-level decisions.

First, though, WHRP needs to learn more about the PIF database and the experiences of the staff that work with it, such as:

• How well the database works

• How staff uses PIF data

• The process for gathering pavement data

• The process for entering new data into the PIF database

• How the database is used by others

• How the database is managed

This winter Jagannath Mallela of Applied Research Associates began investigating WisDOT’s PIF database and contacting the people who deal with it the most. The study is expected to continue through August 2009.

For more information, see the project page of the WHRP Web site or contact Andrew Hanz.

Return to Table of Contents

Keeping Sand at Bay: Research Points WisDOT Toward More Accurate Sand Data
0092-05-08, Determination of Shear Strength Values for Granular Backfill Material Used by the Wisconsin Department of Transportation

One of the jobs of WisDOT soils and foundations engineers is to design retaining walls to hold back fill from a highway construction site. The strength needed by a retaining wall is determined in part by the ability of the fill material to stand on its own. If the stand-alone quality of fill is overestimated, the wall will eventually bulge or even crack under the pressure of the fill.

A soil’s stand-alone quality is its shear strength, a function of both its cohesiveness (or stickiness) and the soil grains’ angles of friction. Since sand has no cohesion, its shear strength comes solely from its grain-to-grain friction.

WisDOT has relied on FHWA standards to determine expected friction angles of sand, and has designed walls accordingly. But several years ago WisDOT found that its sand provides less friction than expected, suggesting that retaining walls may be underdesigned.

Tuncer Edil of UW-Madison led a WHRP investigation of the physical characteristics and shear strength of 30 sand samples from around Wisconsin. Edil’s team developed:

• A simple, repeatable method for measuring shear strength in any lab

• Correlations between shear strength and geologic origins in Wisconsin

• Correlations between friction angles of sands and grain size, particle roundness, and dry weight

With this information, WisDOT will review and update its own shear strength testing methods and data. Walls will be built more precisely, keeping backfilled sands where they belong along state highways—safely and firmly behind walls.

For this study’s final report and research brief, see the project page of the WHRP Web site. For more information, contact Andrew Hanz.

Return to Table of Contents

Regional and National Collaboration

Frozen Four—New Material on Web Site; Group to Meet in April in Madison

The North Central Pavement Research Coordination Partnership pooled fund project has been renewed though 2010, with WisDOT committing $20,000 a year and WHRP continuing to coordinate activities. Additional states in the Upper Midwest are being invited to join this
collaborative effort.

Representatives of the four partner states—Illinois, Michigan, Minnesota and Wisconsin—will meet April 3 in Madison. The agenda will include follow-up to the group’s October workshop on testing resilient modulus of soils and discussion of the 2008 work plan.

Several new documents are available on the Frozen Four Web site, including:

• Minutes from the October meeting

• The project’s 2008 work plan, which includes an annual technical workshop and follow-up research on topics of most pressing interest to members

• A Transportation Synthesis Report on research into resilient modulus of subgrade materials

• A comparison of partner research to a geotechnics research road map

• A report from the October workshop on resilient modulus testing

• Partner state problem statements

Read these reports and more on the Frozen Four Web site.

Return to Table of Contents

WHRP Checks in With FHWA Warm-Mix Group

Warm-mix asphalt is one of the green pavement technologies that are emerging in the highway industry. By using asphalt mixtures that can be mixed and compacted at temperatures of up to 100 degrees Fahrenheit lower than conventional mixtures, agencies can dramatically reduce fuel use and greenhouse gas emissions.

The technical challenge is to develop mixes that not only are workable at lower temperatures, but also resist the damage and fatigue associated with mixing and compacting asphalt at overly cool temperatures.

Andrew Hanz, program manager of WHRP, attended a meeting of the FHWA-sponsored Technical Working Group on warm-mix asphalt in December.

Hanz heard presentations on various warm-mix technologies, including:

• Mineral- and water-based mixtures using additives and various levels of recycled asphalt pavement

• Foamed asphalt technologies

• Flow-improvement additives that allow lower temperatures

• Various warm-mix emulsions

• A new waterless warm mix

The presentations suggest potential for application of warm-mix technologies in Wisconsin, and WHRP may pursue projects related to warm-mix asphalt alone or in cooperation with the Asphalt Research Consortium.

Review presentations from the meeting and other material at the WMA Web site. Contact Andrew Hanz for information on the technical working group.

Return to Table of Contents

Modified Asphalt Research Center—MARC

As the first year of the FHWA-funded Asphalt Research Consortium nears completion, the participation of the UW-Madison research team has yielded valuable results related to asphalt properties, modeling, testing and performance. Among its tasks, the UW-Madison team leads the consortium in the area of modified asphalts. Modified—or engineered—asphalts promise improved properties and performance through the use of additives and novel production processes.

The UW-Madison team sees additional opportunities and research needs for modified asphalts beyond the scope and time frame of the Asphalt Research Consortium, which is funded for five years. The long-range vision for modified asphalts includes the complementary energy-saving goals of developing “green” mixes (requiring less energy to construct) and high-performance mixes (requiring less energy to replace).

To help involve additional research partners and more closely integrate WHRP's work and input in this area, Dr. Hussain Bahia is in the process of formally proposing the Modified Asphalt Research Center at UW-Madison. MARC will be a global leader in the field of modified asphalt research, with the stated purpose of leading "fundamental research in the field of superior asphalt paving technologies" and pursuing the most promising avenues of investigation that emerge.

MARC will seek involvement of partners in government, academia, private industry and stakeholder associations, and will serve as a resource to WisDOT. Center activities will be coordinated with WHRP and other research on better materials for paving. WisDOT experts will be invited to participate in MARC activities to share knowledge and improve practice.

For more information, see the proposed center’s Web site, and contact Hussain Bahia for information on partnership opportunities.

Return to Table of Contents

Outreach

WHRP Maintains Profile at Local Conferences

Program Manager Andrew Hanz has been keeping WHRP in view at local industry conferences.

At the Wisconsin Transportation Builders Association contractor conference, held January 30 in Madison, Hanz attended sessions and set up a poster with information on WHRP. 

On February 12, Hanz manned a booth with WHRP research briefs and brochures at the Wisconsin Concrete Pavement Association’s annual workshop in Appleton.

Hanz also attended the ACEC/WisDOT Transportation Improvement Conference in Elkhart Lake March 11 and 12, and will likely also attend WisDOT’s Project Development and Technical Services Chiefs’ meetings this spring and summer.

For information on WHRP outreach activities, contact Andrew Hanz.

Return to Table of Contents

Implementation Report

TOCs to Adopt New Implementation Procedures

At the February 18 meeting of TOC chairs, Technical Director Hussain Bahia reviewed the new implementation procedures that WHRP will employ to improve the effectiveness of its research by ensuring that field-ready research results get to the people who can use them.

Ensuring the transfer of technical findings to DOT practices is one of the most challenging tasks faced by research programs like WHRP. The new implementation procedures will focus on increasing emphasis on implementation within the TOCs, and also on developing partnerships between TOCs and the WisDOT technical teams that review and update standard specifications and construction procedures.

Elements of the new procedures include:

• TOCs will review implementation plans and project final reports to determine a project’s implementability.

• If implementable, the TOC will determine desirable changes in practice or standards and identify a champion of the changes.

• The champion will discuss the findings with the WisDOT technical team.

• If further implementation or pilot work is needed, the champion will work with WHRP and the technical team to get the work done.

Click the image at right to view the final implementation process flow chart in PDF format. Contact Hussain Bahia with any questions or to request additional information.

Return to Table of Contents

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.

Return to Table of Contents