Request for Proposal
Project 06-02
Use of Recycled ASR PCC Materials in HMA Airfield Pavements

Proposals Due May 11, 2007

Airfield Asphalt Pavement
Technology Program (AAPTP)

PROBLEM STATEMENT

Recycling existing pavement materials is a proven economical benefit for airfield pavements. The use of crushed recycled portland-cement concrete (PCC) pavement material is a recycled material that is being looked at as an alternative source of aggregate. In many cases, the older PCC pavements that are being considered for recycling suffer from distresses associated with alkali silica reactions (ASR) in the aggregates. The long term suitability of these ASR recycled concrete aggregates (RCA) when used in new hot mix asphalt pavement (HMA) is unknown. HMA pavements using RCA materials will be subjected to a wide range of processing and climatic conditions that may accelerate, retard, or even stop the ASR related deterioration. This project will examine the potential for continued ASR reaction within the HMA mixture, determine possible remediation procedures and evaluate the effects on long term performance of the HMA pavement for airfield conditions.

Objectives

The objective of this study is to provide comprehensive technical guidance on the use of aggregates from ASR damaged PCC pavements when used in HMA airfield pavements. The selected contractor shall investigate and determine the allowable severity of ASR damage and potential for additional distress of the original ASR distressed PCC pavement, recommend treatment or pretreatment of recycled PCC pavement containing ASR distress, and determine the long term potential for distress in the HMA from the ASR affected RCA materials. This study is divided into two phases. Phase I will consist of a literature and field performance review of actual and perceived problems associated with the use of ASR RCA materials in HMA, and development of a comprehensive detailed laboratory work plan to be conducted in Phase II. The work plan shall address the shortfalls and gap in knowledge on the subject and recommend laboratory tests and/or modification of tests required to validate initial assumptions on the effects of using ASR affected materials in HMA pavements. Phase II of the project shall consist of conducting the work plan that was developed and approved in Phase I. The Phase II work plan is to provide a systematic evaluation of the recommended approach to successfully use ASR affected RCA materials in HMA Pavements.

Note: The investigator is encouraged not to accomplish the gathering of information by conducting a massive written survey of many airports and State DOTs. A survey is defined as the random distribution of a standard list of questions that seek trends for forecasting information. The use of such surveys must receive approval through the AAPTP from the Office of Management and Budget (OMB). That process requires a minimum of 90 days from the date of application for the survey approval.

Specific characteristics for airfield pavements that should be considered in this project include but are not limited to the following:

  1. Severity of ASR related distress in existing PCC pavement, amount of cracking and gel, and potential for continued ASR reactions in RCA HMA
  2. Geographical and climate variations in airfields that may be subjected to ASR related distress
  3. Use of de-icing chemicals that may accelerate ASR type reactions in the RCA HMA
  4. Type of aircraft and traffic frequency

The project should also address but not be limited to the following elements related to the ASR mechanism:

  1. State of formation of the ASR gel and cracking within the existing PCC distressed pavement, for example - fully formed (reaction complete) or still active (reaction and volume change continuing)
  2. Chemical and petrographic analysis of ASR RCA crushed material
  3. Assessment of changes that will occur in the RCA materials as they are processed into a HMA product
  4. Understanding of the ASR distress mechanisms as they may affect HMA - both long and short term
  5. Potential for continued reactivity of the RCA materials
  6. Outside sources of alkali that may accelerate or continue the ASR process
  7. Assessment of accelerated laboratory test results of RCA or HMA containing RCA compared to long term HMA field performance

Potential Reference Sources

The Federal Highway Administration is in the process of publishing a new Technical Advisory on the use of recycled concrete aggregates back into PCC. This and other sources of information may be of potential use to researchers regarding RCA production and properties. The following is a list of web sites that may be of interest:

http://www. rmrc.unh.edu/Resources/PandD/RCAReport/RCAREPORT.pdf
http://www.fhwa.dot.gov/paveme nt/recycling/rca.cfm
http://www.fhwa.dot.gov/pav ement/recycling/revrca1.cfm
http://www.tfhrc.gov/hnr20/recycle/ waste/rcc1.htm

Product

The products for this project shall consistent of: (1) comprehensive review of references and recent experiences using ASR affected RCA materials in HMA pavements; (2) summary of tests used for determining the distress potential of HMA mixtures containing ASR affected RCA materials; (3) review and trials of pretreatment or changes in the HMA construction procedures to minimize potential effects of ASR materials; and (4) a report on the laboratory testing program to validate the distress potential of using ASR affected materials. These products shall be developed by addressing the following tasks:

Task 1 -- Literature search and comprehensive review of ASR pavements issues and review of field projects using ASR affected RCA materials in HMA pavements.

Task 2 -- Identify sources of ASR RCA materials for laboratory testing. The AAPTP will assist with identifying potential sources of materials and providing contacts to access the sites. Three sources of materials from Air Force project that have been tentatively identified are: Holloman AFB, NM; Edwards AFB, CA and Dover AFB, DE. Mr. James Greene, AFCESA, has agreed to assist in arrangements and points of contact for Air Force facilities. Collection and shipping of the RCA materials shall be included in the cost estimates for this project.

Task 3 -- Identify potential mechanisms for continued ASR distress within the HMA and site conditions that may cause future ASR related distress in HMA airfield pavements and identify laboratory tests to determine potential for reactivity of the RCA of the HMA.

Task 4 -- Assess the potential differences between accelerated laboratory testing and actual long term field performance.

Task 5 -- Provide a preliminary report outlining findings to date and future actions that are recommended. The report is expected to be presented to the technical panel at a mutually agreed upon location 6-8 months after award. The purpose of this meeting is for the technical panel to provide comments on the completion of Phase I and to fully understand and provide comments/adjustments to the work to be conducted in Phase II.

Task 6 -- Conduct laboratory testing and assess results as identified and approved in the detailed work plan for Phase II that was provided in Task 5.

Task 7 -- Provide draft final report for panel review and comments. In addition, a draft FAA engineering brief and PowerPoint presentation suitable for initial briefing shall be provided for the research results. The technical panel will provide comments within one (1) month after receiving the drafts.

Task 8 -- Revise report and other documents per panel comments and provide final report, advisory circular and recommended test protocols. Camera ready copy of the final documents and electronic copy in press quality PDF format shall be submitted under this task.

All written documentation will be prepared using Microsoft Word unless otherwise stated. All reports will be the property of the AAPTP and Auburn University and will be supplied in a format that complies with the FAA's Section 508 requirements for electronic documents.

Proposal Evaluation Criteria

The proposal will be evaluated on the following criteria:

  1. Demonstrated understanding of the ASR problem in PCC and the scope of the project to study the potential effects of using RCA with ASR issues in HMA;
  2. Ability to explicitly state potential mechanisms by which ASR RCA could manifest undesirable behavior in HMA, how the RCA and HMA production and construction process might exacerbate or mitigate the problem, and what testing technologies or concepts may be helpful in evaluating the issues;
  3. Merit of the proposed approach and planned execution of the tasks;
  4. Experience, qualifications, and diversity of the research team;
  5. Plan and/or ability for application of results for airfield use;
  6. Manpower and cost structure

Reporting Requirements

Progress Reports

Quarterly progress reports (1 hard copys and an electronic copy in Microsoft Word format) are required from the research agency and are to be prepared on the basis of calendar quarters. The research agency will mail the report directly to the AAPTP and will e-mail each of the members of the technical review panel a copy of the progress report. Each report will include a cover letter and the following:

  1. a clear and complete description of the work performed on each task during that quarter;
  2. an outline of the work to be accomplished during the next quarter;
  3. a description of any problem(s) encountered or anticipated that might affect the completion of the project within the time and fiscal constraints recommended;
  4. provide potential solutions to problems identified in (c) if any exist.

Report Format

The formats for the Interim and Final reports are provided under "Research Process."

Contractual Information

Funds Available: $150,000

Contract Time: 18 months (includes 1 month for AAPTP to review and for the contractor to revise the final report.)

Staff Responsibility: Monte Symons, 334-844-4964, symonmg@auburn.edu

Proposals Due: May 11, 2007

Submit Proposals To: AAPTP, 277 Technology Parkway, Auburn, AL, 36830

Authorization to Begin Work: June 10, 2007 -- estimated


Maintained by Linda Kerr