Expert Task Group on Asphalt Mixtures & Construction; Asphalt Binders; and Models Technology (ETG) February 2003 Meeting Minutes
NEXT MEETING of the Superpave Mixture and Aggregate ETG is scheduled for Tuesday, September 16, starting at 1:00PM to Thursday, September 18, 2003 concluding at Noon in a location to be determined, possibly in Las Vegas, Nevada.
FOLLOWING MEETING is scheduled for Monday, February 16, starting at 1:00PM to Wednesday, February 18, 2004 concluding at Noon in Washington, DC at the National Academy of Science or Tampa, Florida (There may not be a joint meeting).
A joint session of the Binder ETG and Mixture/Aggregate ETG was convened on February 11 by Mixture/Aggregate Chairman Jim Musselman of the Florida Department of Transportation (DOT) and the Binder Vice-Chairman Gaylon Baumgardner with Paragon Technical Services, Inc. Those members of the Mixture/Aggregate ETG attending were:
|Jim Musselman, Florida DOT (Chair)
Tom Harman, FHWA (Acting-Secretary)
|Ron Sines, PJ Keating (Vice-Chair)
|Jimmy Brumfield, Mississippi DOT
John Cheever, Aggregate Industries
Erv Dukatz, Mathy Construction
Kevin Hall, University of Arkansas
Mike Anderson, Asphalt Institute
Wade McClay, Maine DOT
Karl Frick, California DOT
John D'Angelo, FHWA (Binder ETG liaison)
Ed Harrigan (NCHRP support staff)
|Gerry Huber, Heritage Research
Frank Fee, Citgo Asphalt
Lon S. Ingram, Kansas DOT
Todd Lynn, APAC Inc
Jay Winford, Louisiana Roads & Bridges
Judie Ryan, Wisconsin DOT
David Newcomb, (Industry liaison - NAPA)
Ted Ferragut, TDC Partners (TRB support staff)
Julie Nodes, Arizona DOT
|Members not in attendance:|
|Adam Hand, Granite Construction Co.
John Bukowski, FHWA
Charles Marek, Vulcan Materials
|Richard Kim, NC State University
Rick Harvey, Wyoming DOT
|Those "friends of the Mixture/Aggregate ETG" attending were:|
|Geoff Rowe, Abatech
Bernie McCarthy, Asphalt Institute
Dave Savage, AMRL
David Jahn, Martin Marietta
Gale Page, Florida DOT
Paul Messersmith, APAC
Frank Dalton, Pine Instrument Co.
Mike Bienvenu, Troxler Laboratories
Allen Cooley, NCAT
Don Christensen, AAT
|Ernie Bastian, FHWA
Katherine Petros, FHWA
Ala Abbas, Washington State University
Leslie McCarthy, FHWA
Bob Peterson, Asphalt Institute
Ali Regimand, Instrotec Inc
Ken Brown, Troxler Laboratories
Gaylon Baumgardner, Paragon Tech Solutions
Jack Weigel, Payne and Dolan
Gayle Page, Koch Pavement Solutions
DAY 1: Joint Session
Call to Order - Musselman (Florida DOT), Baumgardner (Paragon)
Chairman Musselman and Vice-Chairman Baumgardner welcomed the group and thanked the National Academy of Sciences for hosting the meeting. They recognized attendees, new members, reviewed the agenda for the joint session, and called for self-introductions (Attachment A).
Update on John Bukowski - Harman (FHWA)
Shortly before Christmas 2002 with the assistance of a heart pump, John was able to finally return home after almost 9 months in the hospital. He was also able to make it back into the office and check on his 47,582 e-mails. On January 10, 2003, the Friday before TRB, John received a new heart and is currently home recovering and doing very well. John is working, telecommuting, and is also working on building up his strength. Please keep him and his family in your thoughts and prayers.
Update of Selected NCHRP Projects - Harrigan (NCHRP)
Dr. Ed Harrigan briefed the ETG's on the status of selected NCHRP projects (Attachment B). Detailed synopses of the projects are provided on the Transportation Research Boards web site: www4.trb.org/trb/crp.nsf/
Status of Projects 90-07 / ALF Pooled Fund - Harman (FHWA)
Tom Harman briefed the ETG's on the status of NCHRP 90-07 and the associated pooled fund project (Attachment C). NCHRP 90-07, entitled, "Understanding the Performance of Modified Asphalt Binders in Mixes," is being conducted by the FHWA and funded by NCHRP and pooled funds. The focus of this study is to conduct laboratory binder and mixture characterization to validate and assess proposed enhancements to the Superpave binder specification. The Modifiers included in the study were identified in cooperation with the Binder ETG. 90-07 is building on a previous study conducted by FHWA entitled, "SHRP Binder Validation," where three un-modified and two modified materials were tested in the laboratory and at the FHWA Pavement Testing Facility (PTF). The new study incorporates nine new modifiers and two un-modified materials. Laboratory testing includes new protocols for the DSR (dynamic shear rheometer) and mixture performance testing including: proposed simple performance test, Superpave shear test (SST), French (Loaded wheel tester) and Hamburg loaded wheel tester.
The FHWA PTF test lanes were constructed in the summer of 2002 and loading on the sites began in November 2002. Preliminary laboratory mixture testing indicates the inability of the current PG specification to capture modified binder performance.
The FHWA continues to solicit State support for the pooled fund. Additional funding is required to complete the loading and analysis of the test sections. The products of this study will include:
- Full-scale accelerated validation of the proposed changes to the Superpave binder specification;
- Validation of the proposed simple performance test with polymer modifiers;
- Full-scale validation of the proposed 2002 Design Guide models with polymer materials;
- Assessment of the applicability of the 2002 Design Guide models to recycled materials; and
- Evaluation of innovative testing equipment (Geo-gauge) to conventional methods.
TRB Superpave Committee - Ferragut (TDC Partners)
Ted Ferragut briefed the group on the committee's activities (Attachments D).
Report of Mixture/Aggregate ETG Activities/Issues - Musselman (FDOT)
Chairman Musselman provided a recap of Mixture/Aggregate ETG activities (Attachment E). The following is a summary of ongoing goals and activities:
- AASHTO Subcommittee on Materials Issues
- Superpave Gyratory Compactor
- QC/QA Proposed Standard Practice
- Aggregate Issues
- Simple Performance Test
Report of Binder ETG Activities/Issues - D'Angelo (FHWA)
John D'Angelo (Secretary Binder ETG) provided a recap of Binder ETG activities (Attachment F). The following is a summary of ongoing goals and activities:
- Highlighting that the existing suite of tests still need refinement.
- Low-Shear Viscosity (LSV) is being considered by the ETG for high temperature characterization of asphalt binders.
Report of Communications ETG Activities/Issues - Masson (TRB)
Linda Masson provided an overview of the Communications ETG activities (Attachment G). The following is a summary of ongoing goals and activities:
- Our mission:
- To have the Superpave system recognized as a cost-effective, high-quality alternative to traditional HMA mix designs.
ACTION: Mason highlighted the electronic newsletter being distributed and requested the ETG provide substance for upcoming issues. The next issue is scheduled for May/June of this year.
Technical Presentation on Binder Grade Selection Using "Degree Days" - Mohseni
Dr. Ala Mohseni presented on the use of "Degree Days" for binder performance-grade (PG) selection. "Degree Days" accounts for the pavement structure, environment, and damage to determine critical pavement high and low temperatures. Damage is assessed based upon the proposed models being developed under NCHRP 1-37(A), (Attachment H).
End Joint Session --
Mixture/Aggregate ETG- Musselman (FDOT)
Chairman Musselman welcomed the attendees to the official start of the Mixture/Aggregate Expert Task Group. The Chairman challenged the attendees to actively participate in the meeting and discussion.
Logistics- Sines (PJ Keating)
Vice-chairman Ron Sines reviewed the basic logistics regarding the meeting.
Review of ETG Action Items - Sines (PJ Keating)
The Vice-Chairman recapped the action items from the August 2002 meeting:
Status of Action Items from Last Meeting
- All presenters should forward an electronic copy of their presentation to ETG Secretary. COMPLETED.
- The Chairman requested the members provide any comments to the February 2002 meetings minutes by e-mail by September 30, 2002. COMPLETED.
- Harvey requested a task group to review AASHTO TP 7, 8, and 9. Any proposed changes need to be Rick by February 2003. Dr. Richard Kim volunteered to head up this effort with the assistance of McDaniel (NCSC), Anderson (AI), Cooley (NCAT), Rowe (Abetec), Christensen (AAT), and Myers (FHWA). All proposed changes will be made by January 15, 2003 to Tom Harman. Harman will forward them to the membership and friends for review and discussion at the next meeting. IN-PROCESS.
- Anderson will provide the ETG the 9-16 unsolicited proposal to Tom Harman by September 1, 2002 to be forwarded to the ETG members, for possible recommendation by the ETG to NCHRP. The Vice-chairman will follow up with Dr. Harrigan regarding the ETG's role. IN PROCESS.
- Tom Harman will request from Dr. Harrigan to have the NCHRP 9-26 SGC data shared with the ETG for review and comment by September 30, 2002. PROVIDED.
- Frank Dalton (Pine Instruments) will provide the group with a report on the mold wear issue for review and comment. The SGC-DAV task force will continue to look at this issue. PROVIDED.
- Establish a task group to address the FAA/CAR issue, headed up by Chuck Marek, including: Cheever, Dalton, Christensen, Jahn, Dukatz, Winford, Sholar (FL DOT), Nodes, and Cooley. ESTABLISHED - WORK IN PROGRESS.
- Marek will provide the ETG with an update of the FAA White Paper by September 30, 2002. COMPLETED.
- Marek will provide the ETG with a CAA White Paper by January 30, 2003. TO BE COMPLETED.
- Please provide comments on the QC/QA Proposed Standard Practice to Gerry Huber by September 30, 2002. Establish a task group to do a detailed review of comments: Hand, Ryan, Gallivan, Schiess, Brumfield, Myers, Fee, Lynn, Musselman, and Sines. COMPLETED.
- The Chairman will contact Tim Aschenbrener (CO DOT) to determine what his needs are regarding the QC/QA standard. WE WERE ASKED TO REVIEW THE DOCUMENT IN TOTAL.
- AASHTO SOM is requesting a detailed service manual from the manufacturers on the servicing of the SGC devices, specifying the associated tolerances on the mechanical operation of the compactors. Identifying where the wear is and what specific areas need to be checked. The Chairman will send a letter with this request to the manufacturers by October 1, 2002. NOT COMPLETED.
- The SGC-DAV Task Force will develop a guidance statement, including the rationale and implementation issues, on the use of DAV for review by the ETG and to be forwarded onto the State DOT's by December 1, 2002. IN PROGRESS.
- Attendees to provide Ferragut Research Needs by September 30, 2002, with an electronic copy to Tom Harman. PROVIDED.
- Prepare a summary of Binder ETG concerns as related to mix stiffness for Mix/Agg ETG consideration, (D'Angelo). A PROBLEM STATEMENT WAS INCORPORATED IN THE RESEARCH NEEDS.
- Request AMRL provide the ETG with round robin data on AASHTO T209. IN PROGRESS. KEVIN HALL WILL GET WITH AMRL.
ACTION: Members requested Gerry Huber to send comments on QC/QA specification to attendees.
Discussion of Breakout Sessions - Ferragut (TDC Partners)
Ted Ferragut outlined the possible format for Day 2.
National Concerns - Sines (Keating)
The Vice-Chairman shared some of the many adjustments that are occurring nationally in Superpave: specifically adjustments in Ndesign to increase the level of asphalt binder in the mix to address concerns of mixture performance. As a follow-up to this issue, the following updates were provided to the ETG:
Update on NCHRP 9-27- Cooley (NCAT)
Alan Cooley provided an update of the subject project, (Attachment I). More than half the field projects studied had low density (less than 92% of Rice). Low density is directly tied to high permeability, which related to issues of durability.
Update on NCHRP 9-25 and 9-31- Christensen (AAT)
Dr. Don Christensen provided an update of the subject projects, (Attachment J). Models, which characterize the fatigue and healing behavior, are being employed to identify and relate the interdependence of volumetric properties on pavement performance. Key findings to date include:
- Increased stiffness (decreased strains) can increase fatigue life,
- However, healing is more rapid with lower stiffness materials.
- Age hardening is reduced by the presence of limestone and hydrated lime.
Durability Discussion: Based on Cooley's and Christensen's presentations.
- Preliminary data from 9-9(1) indicates that the current Ndesign table may be over-compacting mixes, resulting in a lower binder content.
- All things being equal, stiffer binders and lower binder contents result in more durability problems.
- A distinction in recommendations must be made between modified and un-modified binders; where grade-bumping into modified binders will most likely reduce fatigue issues.
- There is the issue of recurring low-density in the field.
- The group discussed examples of the connection between fatigue and rutting.
- The Asphalt Institute commented on States that are experiencing durability and compaction problems.
- Some States are using "Fine Graded' mixes for surface courses to address this issue.
- VMA controls asphalt content. Ndesign only has a minimal impact on asphalt content.
- It is possible that 9-25 and 9-31 will come out with recommendation for minimum binder contents, although how this will be addressed in the specifications is still under consideration. Adjusting Ndesign will not assure an increase in binder content.
- The single best predictor of fatigue response is binder content.
ACTION: To prepare an article for HMAT (and others) on this issue to discuss these concerns, prior to the completion of the ongoing NCHRP projects.
The Vice-Chairman asked Cooley and Christensen to put together an outline of what the article should cover.
Chairman Musselman again welcomed the group.
Next Generation of Laboratory Compaction- Harman (FHWA), Hall (UAF)
Tom Harman reviewed the proposed changes to AASHTO T312-03, entitled, "Preparing and Determining the Density of Hot-Mix Asphalt (HMA) Specimens by Means of the Superpave Gyratory Compactor," (Attachment K and L). A motion was passed by AASHTO to move the standard to concurrent ballot with the changes as noted. The new standard will be published in June 2003. In addition, a separate provisional standard (TP) has been developed for the dynamic angle validator (DAV) operation. Repeatability and reproducibility (precision and bias) for the external angle (Method A) is being completed by AMRL under NCHRP 9-26.
Kevin Hall updated the ETG on the DAV task group. The DAV task group has completed ruggedness of the DAV procedure, (Attachment M). Mixture stiffness appears to still be an issue on the setting and operation of the gyratory. Frame compliance draws into question what mixture should be used with DAV.
ACTION: The DAV task group requests that anyone conducting an assessment of DAV share their information with the task group.
ACTION: The DAV task group is continuing research in this area and will develop a guidance statement.
- A guidance statement for addressing potential sources of gyratory compactor variability and use of the DAV should be out by this spring.
- It is still important to address mix handling and testing procedure issues in order to identify sources of variability.
- AMRL: It is important to establish the uncertainty of the DAV if you're using it for verification.
- In short order there will be a new binder specification that will be considered "Superpave II". It would be beneficial if the latest technology (i.e., DAV, simple performance test, LPI) was incorporated under the Superpave II banner.
- The simple performance test requires taller specimens- would need 250 mm of effective mold height. DAV also takes up space and results in the need for a taller specimen - close to 250 mm.
- Should the next generation of SGC include a requirement for frame stiffness? What is the best way to do that? Also, consider the stiffness of the platens. What about specifying the steel quality?
- The ability to consider pressure during compaction may also be a desirable feature of the next generation SGC.
- Why can't we go to a 2.0o angle?
- Most of the work done on the Ndesign table was based on the 4140 SGC, which tend to have a lower angle. A concept of variable compaction with fixed volumetrics was presented.
- Comment: Think even broader and consider other types of compactors.
- Do we want to put out a new SGC spec to address: 1) Today's needs? 2) Future needs (SPT)?, or 3) Different types of compaction?
- Also need to incorporate ease of maintenance into a new SGC specification.
- What is the interest of the SOM in having a new SGC specification? Many SOM members will need to go back and consult with their experts to decide.
- Does the ETG feel there is a need for a new SGC specification? SHAs don't yet see the need - the SPT isn't out there yet enough and some are not seeing angle issues. In the future, it may be more of a need.
- When you change the equipment standard, what happens to the equipment that is already out there? Need to consider standardization with the equipment that's in use now. We may not want contractors to go out and buy this next generation SGC as it may be more oriented towards research.
- Suggestion: Develop a white paper that defines a research grade compactor. (DAV Task Force)
- Equipment manufacturers feel they can address the-SGC needs.
- If a pooled fund purchase of the 9-29 SPT devices occurs, you could possibly "piggyback" a purchase of research grade SGCs.
- Couldn't you harmonize equipment by calibrating them to a certain result?
- There may be a way to beat the radial gradient and aggregate orientation issues.
- Getting new SGC compactors is going to be a very hard sell unless we could really prove a benefit.
- Still, there is a desire to be able to purchase a better piece of equipment when it comes time to replace the compactor that you have.
- If you truly have a performance test, does it really matter what your gyratory can do as long as you meet the required performance standard?
- It is not yet clear the impact that the SPT values are going to have on the industry. In a few years we'll know. A research grade gyratory may be too premature.
- Europeans are currently addressing related issues which should be watched. (EN12-697)
- ETG would like a rough guidance statement before leaving today.
- Present to the SOM and that the FHWA may possibly buy 6 research-grade gyratory.
ACTION: Section 4.8 of T312-03 requires the manufacturers to develop recommendations for mechanical aspects?(i.e., wear, and proper repair).
Kevin Hall and Julie Nodes (Arizona DOT) led a discussion on the SGC Variability Guidance Document; research-grade gyratory compactor; next-generation HMA mix design procedure; and ultimate laboratory compactor, (Attachments N and O).
ACTION: The DAV task group will develop SGC Variability Guidance Document by the Superpave Committee Meeting on March 31, 2003. The Mixture/Aggregate ETG will be provided with electronic versions of the document for review prior to the committee meeting.
Research & Future Activities, Defining Our Vision- Ferragut (TDC Partners)
Ted Ferragut facilitated discussion on research and future activities to generated an updated list of needs, (Attachment P)
|E*| Testing of Modified Binders- Harman (FHWA)
Tom Harman updated the group on the status of NCHRP 1-37A, 9-19, and 9-29 asphalt modulus characterization and provided data on modified binders tested under the protocol, (Attachment Q). The Binder ETG has concerns of |E*|'s ability to capture modified binder performance. Harman presented preliminary data on FHWA's modified binder study. Permanent strain measured during the test may aide in adjusting |E*| or ranking materials.
The Track and Things - NCAT Update- Cooley (NCAT)
Alan Cooley provided presentations on Superpave gyratory mold wear, the CoreLokTM, and NCHRP 9-9 Ndesign studies, (Attachment R, S, T).
CoreLok - Lively discussion was held on what we are measuring and trying to determine. Ndesign study - Data presented demonstrated that there does not appear to be one Ndesign based on traffic; however, an average Ndesign should be attainable.
Other Things - Asphalt Institute (AI) Update- Anderson (AI)
Bob Peterson provided a presentation on an "Evaluation of Infinite Fatigue in HMA Mixtures," (Attachment U).
Update on Aggregate Issues - Jahn (Martin Marietta)
David Jahn briefed the group on his research on the Compacted Aggregate Resistance (CAR) test. Efforts are underway to better standardize the test concepts, (Attachment V). Data presented showed reasonable repeatability with the CAR test. Discussion was held regarding the impact of moisture on the CAR test as well as the gradation of the tested materials. The CAR is being proposed as a possible aggregate screen test to replace the FAA. The CAR uses 4-inch Marshall Molds, 50 blows on one side, and a modified Marshall press to obtain results.
ACTION: The CAR Task Team is to finalize and conduct an experimental plan.
The Chairman convened the meeting at 8:00 AM and reviewed items to be covered:
- AASHTO Standards
- QC/QA Standards
- Open Forum
AASHTO Standards - Ferragut (TDC Partners)
Ted Ferragut reviewed an Excel spread sheet, Attachment X, which covers the status of Superpave related AASHTO standards. The committee chairmen for the two related SOM technical sections are: 2b: Rick Harvey (WY DOT) and 2d - Tom Baker (WS DOT). Ferragut polled the group to refine and update the list.
QC/QA Discussion - Huber (Heritage Research)
Gerry Huber led a discussion on "Standard Practice to Develop a Quality Control/Quality Assurance Plan for Hot-Mix Asphalt," Attachment Y. This document is designed to aide State agencies with developing an effective QC/QA program for HMA. Huber thanked the ETG members for their review and comments of the document.
General discussion included:
- Mix design (laboratory)
- Job mix formula (production - must still meet MP-2)
- How do you handle allowable adjustments? Go / No Go.
- Acceptance: PWL using Standard Deviation or Conformal Index / Mean and Range
- The group recommended more focus on dispute resolution in the document.
ACTION: After lengthy discussion, Huber recognized the limits and the benefits of the document. Huber feels we have reached a consensus. He will address comments raised during the discussion and forward the document to Tim Aschenbrener (AASHTO Tech Section Chair).
The attendees provided areas for further discussion, research, and implementation:
- Future Role of the ETG.
- Durability Article Outline, Attachment Z.
The Vice-Chairman indicated he would add additional items to the minutes the ETG may want to consider at a future meeting based on issues raised at a recent NAPA Best Paving Practices Workshop. These items include: identification of cessation temperatures for compaction in the field, improved methods of identifying segregation in the field, tack coat related issues (value of tacking, materials used, application rates), mixture temperature issues (TXDOT specification for temperature gradient in the truck, value of tarping loads), and develop improved methods for the construction of longitudinal joints.
The Chairman thanked all the guests, new members, members, Vice-chairman, and Acting Secretary for their support and input over the past two days.
The Chairman recapped the Action Items provided below.
The meeting was adjourned at 11:30 AM.
Old Action Items
- Establish a task group to address the FAA/CAR issue, headed up by Chuck Marek, including: Cheever, Dalton, Christensen, Jahn, Dukatz, Winford, Sholar, Lynn, Nodes, and Cooley. ESTABLISHED - WORK IN PROGRESS.
- Marek will provide the ETG with a CAA White Paper by January 30, 2003. TO BE COMPLETED.
- Request AMRL provide the ETG with round robin data on AASHTO T209. IN PROGRESS. KEVIN HALL WILL GET WITH AMRL.
New Action Items
- Linda Mason (TRB) has requested the ETG provide substance for upcoming issues of the Communications ETG's electronic newsletter. The next issue is scheduled for May/June of this year. We need commitments?
- Summation of ETG activities? Musselman
- Provide minutes for article mining? Harman
- SGC Issues? Hall
- Durability - Action item 2.
- Prepare an article for possible publication (HMAT, etc.,) on the durability discussion, prior to the completion of the ongoing NCHRP projects. Cooley and Christensen to put together an outline of what the article should cover, draft outline Attachment Z. The Chairs and Dave Newcomb will review the article.
- The ETG requests NCHRP to coordinate the recommendations coming out of 9-9(1), 9-25, 9-27, and 9-31 to ensure consistent recommended specification changes.
- The DAV task group requests that anyone conducting an assessment of DAV share their information with the task group.
- The Chairman will work with the manufacturers to fulfill Section 4.8 of T312-03, which requires the manufacturers develop recommendations for mechanical mechanisms (i.e.. wear, and proper repair). Pine draft statement provided with minutes, e.g., After x number of hours you will replace y.
- The DAV task group will develop an SGC Variability Guidance Document by the Superpave Committee Meeting on March 31, 2003. The Mixture/Aggregate ETG will be provided with electronic versions of the document for review prior to the committee meeting.
- The DAV task group will develop white papers on: 1) research-grade Superpave gyratory compactor; 2) next-generation HMA mix design procedure; and 3) ultimate laboratory compactor. Hall, Nodes, Harman.
- Huber will address comments raised during the QC/QA discussion and forward the document to Tim Aschenbrener (AASHTO Tech Section).
- Ferragut with input from the Binder and Mix/Aggregate ETG Committees will develop a draft-whitepaper on the continuance of the ETG's that outlines the needs for the future and implementation of future HMA developments: e.g., Superpave II, SPT, 2002 PDG, etc.
- The ETG will provide Ferragut with final comments on Research Brainstorming by March 15, 2003.
Members and Liaisons: Email addresses not available from this website
Friends and Old Friends: Email addresses not available from this website
List of Electronic Attachments:
(not available from this website)
- Mix-Agg ETG Agenda Feb 2003
- Harrigan - NCHRP Update
- Harman - ALF 2 Status Feb 03
- Presentation to the Joint Committee
- Musselman - TRB Superpave ETG Update - February 2003
- DAngelo - Binder ETG update 2-03
- Mason - Superpave Communications & Training ETG
- Mohseni - Degree Days
- Cooley - Durability Issues
- Christensen - NCHRP 9-25 9-31 Update
- Harman - Proposed Changes to T312-03
- Harman - Next Generation Lab Compaction
- Hall DAV Update - ETG Spring 2003
- Hall - SGC Variability Guidance Document
- Hall - Future Needs - Mix Design and SGC
- Ferragut - Research Brainstorming Session, Version 3.2
- Harman - Complex Modulus
- Cooley, Ndesign
- Cooley, CoreLok
- Cooley, Asphalt Pavement Analyzer
- Peterson - Infinite Fatigue Presentation for ETG
- CAR Ruggedness
- Superpave Timeline from Status Report
- AASHTO SOM Status of Standards
- Huber - QC-QA
- Durability Article