AASHTO Joint Task Force on Pavements

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					                       AASHTO Joint Task Force on Pavements
                                Meeting Minutes
                            November 12 and 13, 2002
                               Myrtle Beach, SC

·   Agenda

·   Minutes of the November 12 and 13, 2002 Meeting

·   Attendance list

·   List of Attachments (available at
    ·       NAPA perspective.ppt
    ·       ACPA perspective.ppt
    ·       Development of a High-Speed Deflectometer.ppt
    ·       2002 Flexible Pavt.pdf
    ·       NCHRP Pavement Research: An Overview

                              Joint Task Force on Pavements

                                  November 12-13, 2002


November 12

 1:00 – 1:30 p.m.     Introductions and Welcome                        Gary Sharpe
 1:30 – 2:15 p.m.     NAPA Perspective                              David Newcomb
 2:15 – 3:00 p.m.     ACPA Perspective                                Gerry Voigt
 3:00 – 3:15 p.m.     Break
 3:15 – 3:45 p.m.     NCHRP Pavement Research Overview                Amir Hanna
 3:45 – 4:15 p.m.     AASHTO Overview                                Ken Kobetsky
 4:15 – 4:35 p.m.     FHWA Items                                     Tommy Beatty
 4:35 – 5:00 p.m.     Rolling Wheel Deflectometer                      Max Grogg
 5:00 – 7:00 p.m.     Dinner on Own
 7:00 – 8:30 p.m.     Demonstration of 2002 Design Guide

November 13

  7:00 – 9:45 a.m.    Demonstration on 2002 Guide
  9:45 – 10:00 a.m.   Break
10:00 – 11:30 a.m.    Demonstration on 2002 Guide
11:30 – 12:45 a.m.    Lunch
12:45 – 2:30 p.m.     Demonstration on 2002 Guide
 2:30 – 2:50 p.m.     Break
 2:50 – 4:00 p.m.     Closed Session

       Task Force members plan to adjourn no later than 4:00 p.m.

                           AASHTO Joint Task Force on Pavements
                                November 12 and 13, 2002
                                   Myrtle Beach, SC


Opening remarks by Gary Sharpe

       AASHTO adopted a reauthorization policy that is larger than TEA-21 level. The policy
       also includes an increase for research and $20 M/yr for LTPP. No comments were added
       to the minutes of the last meeting.

FHWA Update: Tommy Beatty

Tommy Beatty started by talking about a few FHWA items that relate to the JTF on Pavements:
reauthorization, restructuring of the Resource Centers, and the Concrete Earmark. He spoke
about the status of each of the concrete projects under the earmark and gave an update on the
Resource Centers. The resources centers will go through restructuring with a long-range plan for
consolidation into one unified center. Any interested party can obtain a copy of the concrete
earmark projects from Tommy Beatty.

AASHTO Update: Ken Kobetsky

Ken Kobetsky from AASHTO also talked about AASHTO’s reauthorization. Some of the sectors
that were discussed were safety, working with the environment, motor carrier security,
operations, asset management, needs for rural roads, capacity, system preservation, alternative
fuel sources, congestion relief, and funding for transportation enhancements (e.g., bike paths).
They would also like to improve environmental streamlining through the Center for
Environmental Excellence. AASHTO is proposing to use innovative techniques for funding and
investments. One effort is to leverage funds though a transportation financing corporation.

All of the information is included on the website: on the reauthorization link.

        He also discussed the idea that the JTF on pavements should expand to include a few
liaisons from the Subcommittee on Materials. Two other subcommittees that they want to reach
out to would be Planning and Aviation (FAA). In return, the JTF will have a report given at
other subcommittee meetings as a liaison from the Pavements side.
        He announced that the Subcommittee on Design will hold a meeting around June 13 to
16, 2003, in Boston. Also, the Subcommittee on Maintenance recently submitted a glossary on
pavement preservation for ballot.

NCHRP Update: Amir Hanna

Amir Hanna from TRB gave an overview of the NCHRP proposal and project status. He noted
that the SCOH approved approximately 43 new projects for 2003. Some of those projects include
implementation of the 2002 design guide, models for reflection cracking (on-hold until the 2002
guide is completed), friction guide including noise and environment, top-down cracking in
bituminous pavements, and recycled aggregates in unbound layers. The 2004 project statement
reviews will be sent to the submitters in December and the projects will then be selected in
March 2003. NCHRP is expecting to have roughly $23 million for transportation research in
        The NCHRP 1-37A design guide deliverables were expected at TRB at the end of
November. There will be four months to review the deliverables. A brief introduction (~ 20
pages) should be submitted with the software. The deliverable for the NCHRP 1-39 traffic data
forecasting is expected soon, as it will be used as input to the 2002 guide.

NAPA Perspective: Dave Newcomb

David Newcomb gave the NAPA perspective and discussed the industry needs for mechanistic
pavement design. Some of the items related to the 2002 design guide that concern NAPA include
reliability sensitivity, precision of models, user understanding of design software, and better
performance estimates from lab studies. Traffic and construction variability are still problems
that cannot be designed for. In terms of reliability sensitivity, NAPA would like to know how the
design procedure handles the real effects of variability on performance. Other questions include
how the models will precisely reflect measurable material properties, as well as better estimates
of the endurance limit and stress reduction (need for laboratory studies exists). He also explained
that although the design models require complexity, the user needs to know where inputs come
from and to avoid cataloging of pavement sections.

The strategic plan and new research areas for NCAT were discussed along with the concurrently
occurring Test Track event and Best Paving Practices workshop.

The World of Asphalt trade show and conference will be held on March 17-19, 2003 in
Nashville, Tennessee.

ACPA Perspective: Gerry Voigt

Gerry Voigt from ACPA discussed the concrete industry perspective on the 2002 design guide.
Some of the main interests include how the new guide compares with the old design procedure
and what are the fatigue models for concrete. He also discussed the ACPA priority research
issues that include smoothness, early cracking, material compatibility, and zero-clearance paving.

IPRF on the Federal Aviation Administration side is still active.

Some of the important issues for concrete industry are smoothness, profilers, and new concrete
mix design process. They would like to come up with one specification for smoothness for all
surfaces (not just PCC or AC). Are profilers really giving us an accurate indication of ride?
Research will be focused on profiles; however, they will stop short of getting into an index since
none of them properly accounted for tining (texturing) and joints on concrete. Iowa is the lead
state in coming up with a new concrete mix design process.

Rolling Wheel Deflectometer: Max Grogg

Max Grogg from FHWA-Iowa office gave a presentation on the Rolling Wheel Deflectometer
which is a dual-tire dynamic tool that runs at highway speed. The lasers and accelerometers are
carried on an insulated aluminum 2 x 8 beam under the rear axle of a tractor trailer. Proof of
concept trials were run in Champaign, IL, in July 2002 and he reported that the data for
deflections looks promising. Deflections are gathered to the 0.001 inch, making the device an
alternative to the Falling Weight Deflectometer (FWD). Need exists to compare network level
testing to project level testing.

Demonstration of the 2002 Pavement Design Guide

Overview of the Guide Project, Mike Darter

An overview of the 2002 design guide was then presented by the Contractors that discussed the
background, software design/analysis process, implementation issues, and benefits of the guide.
The details of the presentation are included in the presentation which is attached.

States can adjust the performance models as needed for local calibration, in order to refine
characteristics and variations in the guide to their state.

Some initial comments from the JTF panel on this portion of the meeting included:
   There is no way to input admixtures (e.g. fly ash) and only regular Type I, II, etc., concrete
  can be evaluated in guide. Gerry Voigt from ACPA thought it would be important to add that
  option to the software.

   Max Grogg suggested that on all the plots for predicted cracking in concrete, there will be a
  box in the bottom right that gives the actual value (e.g., 68% reliability) that a State pavement
  design engineer would be interested in knowing.

   If cracking limits on standard deviation in a State vary from the national norm, the State
  can manipulate the crack reliability equation for concrete. The JTF noted that this capability
  should be limited in order to avoid errors prompted by engineers getting lost in the software.

   The program does not automatically change built-in warping for concrete. The user must
  go in and manually change it.
   Traffic and climate data are all from LTPP sites; however, in the future, the climate data
  could be updated yearly from the NOAA or NCDC data sites.

   The appendices should include details on the calibration equations used for both flexible
  and rigid equations.

   What should the pavement design engineers do for national and State calibration? How can
  they compare this design process to the previous guide?

   An appendix should be added to outline the approximate run times for different types of
  computer systems. Run times should not be different for Level 1, 2, or 3 analyses.

The overview was followed by a software demonstration of the concrete and asphalt design guide

Demonstration of the Software for PCC

An example of two concrete pavement designs were demonstrated using the software.

       Select metric or english at start, but cannot switch back and forth. Main screens are
       general project information, inputs and results. Color coded:
       ·      Red: stop, input is required to run the program,
       ·      Green: user has supplied the required information or selected default input values,
       ·      Yellow: item has a default value or unnecessary inputs, program will use default
              value only after the user approves it.
       ·       …     Help button that does calculations

       Traffic default values for the various classes (17) of vehicles and types of roads were
       drawn from approximately 300 LTPP sites. Traffic type adjustments are per month;
       therefore, numbers must sum up to 12 (for 1 year). Tire pressure can be changed to
       reflect increased tire pressures from Supersingle (wide-based radial) tires. Mechanistic
       models should handle a range of 50 to 200 psi, but Matt Witzcak is recommending
       looking at only 120 to 140 psi. This may be short-sighted to not calibrate models to
       higher pressures (i.e., contact areas) and other tire configurations since the tire industry is
       ever-evolving and producing new tire types.

       Hourly climatic database draws from 800 locations around the US. Also accounts for
       thermal gradients in the pavement, but only at 3 depths (top, middle, bottom) within the
       pavement layer.

The software requires user to define the pavement layers and structure proposed. In
design features, the effects of dense-treated base versus coarse-treated base with respect
to erodibility can be investigated.

Reliability is included in the pavement design models. One issue to be explained was how
they are looking at fairly comparing reliability for different pavement distresses (for
different pavement types). They listed a table with ranges of reliability for different
distress types.

                                       NOVEMBER 13

AC Models, Chuck Schwartz

A presentation on the calibration of the asphalt pavement models was given along with a
demonstration of a flexible pavement design example. The details of the presentation are
included in attached file. Some comments and highlights on the flexible pavement design

          Models designed to account for interaction of distresses and effect on calibration
         (e.g., pavement may have both top-down and bottom-up cracks simultaneously and
         how they influence eachother).

          NCHRP 9-30 reports have some explanation of calibration factors and models for
         rutting and cracking that are used in the Design Guide.

             Some of the damage models for flexible pavement distress (e.g., top-down
         cracking) are not yet completed.

          Cracking data (e.g., cumulative crack length in 500-ft long section) is generated
         from LTPP field data, but only using test at one temperature.

            Traffic wander data from LTPP. Which sites?

              Not enough attention is paid to material characteristics on the flexible pavement
         design. Also, the unbound layer values k1, k2, and k3 must be computer and input by the

          Temperature divisions within the asphalt concrete layer are broken into various
         sublayers in the analysis, but the user does not see how many sublayers are used.
         Temperature is coming from weather stations. Example: in a 10-inch AC layer, the
         pavement temperatures are measured at 3 depths for the routine. In the case of thermal
         and top-down cracking, the model concentrates on temperature in the top one-half inch
         of the pavement layer.

          The analysis type for environmental effects is the Enhanced Integrated Climatic
         Model (ICM). For example, cold weather analysis must be done using the ICM.

          Models not yet calibrated for all of the flexible pavement distresses (e.g., top-down

                                  Closed Session

Items for Discussion:
    Membership increase
    Keeping up-to-date on provisional standards for tests, etc.
    Letter from Gary Hoffman of Pennsylvania DOT
    Variation in Resilient Modulus
    Joint review of draft 2002 design guide
    Upcoming JTF on Pavements meeting

Membership Increase

Item deals with the idea of inviting four (4) members, one from each region of the US,
from the Subcommittee on Materials (SOM) to participate in the JTF on Pavements

Mike Ryan from the SOM is looking for suggestions of names before February and they
want to make sure and get one member from each region.

Members of JTF group should email names to Gary Sharpe (
503-564-3280) within the next month (by December 1, 2002). Gary will then send the
names to Ken Kobetsky.

Panel also discussed coordinating with other subcommittees (FAA, Planning) to invite
member(s) from their respective groups to attend the JTF on Pavements meetings and to
find out if the current contact from their committees is still interested in serving on our
committee. Task Force chairman will first phone and then send a letter to find out.

The possibility of extending an invitation to the US Corps of Engineers to attend, but not
as a member, was also discussed. It was decided that David Pittman would be a contact
but that the JTF would wait until after the 2002 design guide is completed to make the

Recent travel restrictions are making it difficult for State members to attend the JTF on
Pavements meetings. Therefore, the JTF has decided not to ask for replacements from the
States for members who have missed more than two (2) meetings.

Provisional Standards for Tests

Item deals with the keeping up with provisional standards for tests, etc. Some contacts
were identified for:
       P 46           Andy Gisi from Kansas DOT
       TP 7, 8, & 9 Mix ETG task force led by Richard Kim from NC State University
        NCHRP 9-29 Dynamic Modulus of Asphalt, Rick Harvey & FHWA on panel
Gary Sharpe noted that once the provisional standards are balloted and approved, Steve
K. will be invited to brief the JTF on Pavements once the draft is final. Gerry Voigt
(ACPA) requested comments and Ken Fults and Danny Dawood will draft a response to
Gerry Voigt.

Letter from Gary Hoffman of Pennsylvania DOT

Item deals with a letter sent to Gary Sharpe from Gary Hoffman, Chief Highway Engineer
at Pennsylvania DOT. The letter concerns whether or not the JTF can promote the use of
the zero blanking band (ZBB) to get all of the States to get together on achieving
consistent paving. Kansas was identified as having done a great amount of research on the
ZBB. Some states have already moved from ZBB to IRI including Texas, Pennsylvania,
Maryland, and Wyoming to name a few.

The suggestion was made to go around ZBB and start directly promoting IRI. By using
the expertise on the Task Force, group could come up with a “white paper” that explains
the reasons to go towards index-based profile. Specifically, historical examples of States
that have already moved would be helpful. Tom Hearne, Linda Pearce, Andy Gisi, and
Ken Fults will work on the “white paper”.

Variation in Resilient Modulus

Dan Dawood mentioned that the 2002 guide should have endorsement from some
Agency. Gary Sharpe mentioned that once the 2002 Guide is approved by the JTF on
Pavements, that will constitute JTF on Pavements endorsement.

Ken Fults will work with Andy Gisi in deciding which one (128-A) that Matt Witzcak is

Dan Dawood and Amir Hanna will verify what provisions are in the Guide.

Joint Review of Draft Guide

Joint review of the draft 2002 pavement design guide will be done along with the
NCHRP panel review. Amir Hanna noted that the preliminary draft will be made
available to the JTF on Pavements for review. The JTF on Pavements will have 2 months
for review. Amir would like comments to be sent from members to him and he agreed to
send the software to the JTP on Pavements members in order for them to become familiar
with the program.

Upcoming JTF on Pavements Meeting

The next meeting will be held in Little Rock, Arkansas, in mid-May 2003. The
Subcommittee on Design is meeting June 10-13, 2003, in Boston, Mass.

Jackson Hole, Wyoming, will host the following meeting (Seattle and Denver are other

                            Attendance List

     NAME                     ADDRESS                         EMAIL/PHONE
                    6th flr, CUB                       717-787-4246
  Dan Dawood        400 North Street, HBG, PA 17120
   Bill Temple      P.O. Box 94245, Room 400DD
 Jeffrey Lambert    Baton Rouge, LA 70804-9245
                    400 7th Street SW, Room 3118
  Leslie Myers      Washington, DC 20590
                    1980 West Broad St.
   Aric Morse       Cole, OH 43215
                    1019 Erie Ave
 Richard Zamora     Pueblo, CO 81001
                    NCDOT, 716 West Main St
  Tom Hearne        Albemarle, NC 28001
                    NAPA, 5100 Forbes Blvd
 Dave Newcomb       Lanham, MD 21044
                    WSDOT, PO Box 47365
  Linda Pierce      Olympia, WA 98504-7365
                    2300 Van Buren
   Andy Gisi        Topeka, KS 66611
                    444 N. Capitol St. Suite 249
  Ken Kobetsky      Washington DC 20001
                    105 Sixth Street
   Max Grogg        Ames, IA 50010
                    1220 Washington Ave
   Wes Yang         Albany, NY 12232-0869
                    ACPA, 5420 Old Orchard Rd
   Jerry Voigt      Skokie, IL 60077                   847-966-2272
                    VAOT, Nat’l Life Bldg, Drawer 33
Michael Pologruto   Montpelier, VT 05633               802-828-3876
                    5300 Bishop Blvd         
  Rick Harvey       Cheyenne, WY 82009                 307-777-4476
                    MS 28, P.O. Box 942874   
  Kevin Herritt     Sacramento, CA 94274-0001          916-227-7324
                    CST-M&P, 125 E 11th St   
    Ken Fults       Austin, TX 78701                   512-506-5804
                    PO Box 270               
   Jay Bledsoe      Jefferson City, MO 65102           573-751-3634
                    6300 Georgetown Pike, HRDI-12
 Cheryl Richter     McLean, VA 22101-2296
                    400 7th Street SW, Room 3118
 Tommy Beatty       Washington, DC 20590
                    500 5th St NW
  Amir Hanna        Washington DC 20001

                    PO Box 191
Andy Johnson        Columbia, SC 29202-0191
                    Room 608 State Office Bld, 501
 Gary Sharpe        High Street, Frankfort, KY 40622   502-564-3280
                    PO Box 2261              
Phil McConnell      Little Rock, AR 72203              501-569-2301

Missing: George Way, Arizona DOT and Colleen Kissane, Connecticut DOT