Proposals Due May 11, 2007
Airfield Asphalt Pavement
Technology Program (AAPTP)
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.
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.
Specific characteristics for airfield pavements that should be considered in this project include but are not limited to the following:
The project should also address but not be limited to the following elements related to the ASR mechanism:
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:
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:
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:
The formats for the Interim and Final reports are provided under "Research Process."
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, firstname.lastname@example.org
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