BACKGROUND

Geosynthetics are available in a wide range of forms and materials and are used in many applications. Geosynthetics are often used by highway agencies in conjunction with unbound base layers as a means for enhancing the performance of pavements. Test methods are currently available to estimate the performance enhancement resulting from the use of geosynthetics in the pavement structure (e.g., ASTM D8462, Cyclic Plate Load Tests to Evaluate the Structural Performance of Roadway Test Sections with Geosynthetics). However, there is concern about the validation of the test methods and reliability of the resulting estimates. Research is needed to evaluate the merits of the tests currently used for estimating the benefits of geosynthetics and, if necessary, enhance these test methods or develop new methods that can reliably estimate the contribution of geosynthetics to pavement performance. Such test methods will help highway agencies and others in making decisions regarding use of geosynthetics in pavement structure.

OBJECTIVE

The objective of this research is to develop a practical, validated laboratory test method for estimating the contribution of geosynthetics to pavement performance. The research shall be limited to asphalt pavements and use of geogrids and geotextiles in unbound base and subgrade.

Accomplishment of the project objective will require at least the following tasks.

TASKS

Task descriptions are intended to provide a framework for conducting the research. The NCHRP is seeking the insights of proposers on how best to achieve the research objective. Proposers are expected to describe research plans that can realistically be accomplished within the constraints of available funds and contract time. Proposals must present the proposers' current thinking in sufficient detail to demonstrate their understanding of the issues and the soundness of their approach to meeting the research objective.

PHASE I

Task 1. Collect and review domestic and foreign literature, research findings, and information relevant to laboratory test methods for estimating the contribution of geosynthetics to pavement performance. This information may be obtained from published and unpublished sources and from public and private organizations.

Task 2. Based on the review performed in Task 1, identify and evaluate the merits and deficiencies of available test methods and recommend potential tests, modifications thereof, or new methods for consideration in Phase II to develop a reliable laboratory test method for estimating the contribution of geosynthetics to pavement performance.

Note: Proposals shall include the research team’s current thinking regarding the features of available test methods, and the process for evaluating these features and identifying the methods that need to be addressed in Phase II.  

Task 3. Based on the work performed in Task 2, prepare a detailed work plan to be executed in Phases II and III to (1) develop a validated test method for estimating the contributions of geosynthetics to pavement performance and (2) prepare supplementary material to support adoption and implementation. Accelerated pavement testing may be considered for validation. The plan shall provide specific information on the different aspects of the proposed work (e.g., the approach for addressing the deficiencies of the recommended test methods and the process for validating the recommended method).

Note: Proposers must include in the proposal a plan that provides detail on the proposer’s current thinking regarding the work anticipated in Phase II for developing a validated laboratory test method. The work proposed for Task 5 must be divided into subtasks, and proposers must describe in detail the work proposed in each subtask.

Task 4. Prepare and submit Interim Report 1 that documents the research performed in Tasks 1 through 3. Following review of the interim report by the NCHRP, the research team will be required to make a presentation to the NCHRP project panel. Work on Phase II of the project will not begin until Interim Report 1 is approved and the Phase II work plan is authorized by the NCHRP. The decision on proceeding with Phase II will be based on the contractor’s documented justification of the updated work plan.

Note: The contractor shall submit the Phase I interim report within 8 months of contract award and meet with NCHRP within 1 month of report submission. The meeting is expected to be in person in Washington, DC. The NCHRP will host the meeting and be responsible for any panel member costs to attend.

PHASE II

Task 5.  Execute the Phase II work plan approved in Task 4. Based on the results of this work, develop the test method.

Task 6. Prepare draft language for consideration by American Association of Highway and Transportation Officials (AASHTO) to incorporate the research results into a future edition of the AASHTO Standard Specifications for Transportation Materials and Methods of Sampling and Testing, and AASHTO Provisional Standards.

Task 7. Prepare and submit Interim Report 2 that documents the recommended test method and the draft language. Following review of the interim report, the research team will be required to make a presentation to the NCHRP project panel. Work on Phase III of the project will not begin until the report is reviewed and the Phase III work is authorized by the NCHRP.

Note: A review meeting that includes a presentation by the research team shall be scheduled 1 month after submitting interim Report 2. The meeting is expected to be in person in Washington, DC. The NCHRP will host the meeting and be responsible for any panel member costs to attend the meeting. Proposals shall provide the estimated time for preparing and submitting the memorandum.

PHASE III

Task 8. Review and consider the comments on Interim Report 2 and revise the recommended test method and draft language and prepare a draft report documenting the research performed in the project.

Task 9. Prepare presentation material, in a PowerPoint or other format, for use in webinars and presentations to facilitate the use and adoption of the proposed test method.

Task 10: Prepare a stand-alone technical memorandum titled “Implementation of Research Findings and Products” (see Special Note J) to facilitate implementation of the proposed test method.

Task 11. Submit (1) a draft final deliverable that includes (a) a research report documenting the work performed in the project and used to develop the proposed test method, (b) the proposed test method, (c) the draft language, (d) the presentation material, and (e) the implementation plan, and (2) a final deliverable that addresses the review comments.

Note: The contractor shall submit a draft final deliverable within 33 months from contract award. Following receipt of the draft final deliverable, the remaining 3 months shall be for NCHRP review and comment and for research agency preparation of the final deliverable.

SPECIAL NOTES

A. The Information and Instructions for Preparing Proposals for the Transportation Research Board’s Cooperative Research Programs were revised in May 2023. Please take note of the new and revised text which is highlighted in yellow.

B. Proposals must be submitted as a single PDF file with a maximum file size of 10 MB. The PDF must be formatted for standard 8 ½” X 11” paper, and the entire proposal must not exceed 60 pages (according to the page count displayed in the PDF). Proposals that do not meet these requirements will be rejected. For other requirements, refer to chapter V of the instructions.

C. The Information and Instructions for Preparing Proposals for the Transportation Research Board’s Cooperative Research Programs have been modified to include a revised policy and instructions for disclosing Investigator Conflict of Interest. For more information, refer to chapter IV of the instructions. A detailed definition and examples can be found in the CRP Conflict of Interest Policy for Contractors. The proposer recommended by the project panel will be required to submit an Investigator Conflict of Interest and Disclosure Form as a prerequisite for contract negotiations.

D. Proposals will be rejected if any of the proposed research team members work for organizations represented on the project panel. The panel roster for this project can be found at https://www.mytrb.org/OnlineDirectory/Committee/Details/6919. Proposers may not contact panel members directly; this roster is provided solely for the purpose of avoiding potential conflicts of interest.

E. Proprietary Products - If any proprietary products are to be used or tested in the project, please refer to Item 6 in the Information and Instructions for Preparing Proposals.

F. Proposals are evaluated by the NCHRP staff and project panels consisting of individuals collectively knowledgeable in the problem area. The project panel will recommend their first choice proposal considering the following factors: (1) the proposer's demonstrated understanding of the problem; (2) the merit of the proposed research approach and experiment design; (3) the experience, qualifications, and objectivity of the research team in the same or closely related problem area; (4) the plan for ensuring application of results; (5) how the proposer approaches inclusion and diversity in the composition of their team and research approach, including participation by certified Disadvantaged Business Enterprises; and, if relevant, (6) the adequacy of the facilities. A recommendation by the project panel is not a guarantee of a contract. The National Academy of Sciences (NAS - the contracting authority for the National Academies of Sciences, Engineering, and Medicine) will conduct an internal due diligence review and risk assessment of the panel’s recommended proposal before contract negotiations continue.

Note: The proposer's approach to inclusion and diversity as well as participation by Disadvantaged Business Enterprises should be incorporated in Item 11 of the proposal.

G. Copyrights - All data, written materials, computer software, graphic and photographic images, and other information prepared under the contract and the copyrights therein shall be owned by the National Academy of Sciences. The contractor and subcontractors will be able to publish this material for non-commercial purposes, for internal use, or to further academic research or studies with permission from TRB Cooperative Research Programs. The contractor and subcontractors will not be allowed to sell the project material without prior approval by the National Academy of Sciences. By signing a contract with the National Academy of Sciences, contractors accept legal responsibility for any copyright infringement that may exist in work done for TRB. Contractors are therefore responsible for obtaining all necessary permissions for use of copyrighted material in TRB's Cooperative Research Programs publications. For guidance on TRB's policies on using copyrighted material please consult Section 5.4, "Use of Copyrighted Material," in the Procedural Manual for Contractors.

H. The text of the final deliverable is expected to be publication ready when it is submitted. It is strongly recommended that the research team include the expertise of a technical editor as early in the project timeline as possible. See Appendix F of the Procedural Manual for Contractors Conducting Research in the Transportation Research Board’s Cooperative Research Program for technical editing standards expected in final deliverables.

I. Proposals should include a task-by-task breakdown of labor hours for each staff member as shown in Figure 4 in the Information and Instructions for Preparing Proposals. Proposals also should include a breakdown of all costs (e.g., wages, indirect costs, travel, materials, and total) for each task using Figures 5 and 6 in the brochure. Please note that TRB Cooperative Research Program subawards (selected proposers are considered subawards to the National Academy of Sciences, the parent organization of TRB) must comply with 2 CFR 200 – Uniform Administrative Requirements, Cost Principles, and Audit Requirements for Federal Awards. These requirements include a provision that proposers without a "federally" Negotiated Indirect Costs Rate Agreement (NICRA) shall be subject to a maximum allowable indirect rate of 10% of Modified Total Direct Costs. Modified Total Direct Costs include all salaries and wages, applicable fringe benefits, materials and supplies, services, travel, and up to the first $25,000 of each lower tier subaward and subcontract. Modified Total Direct Costs exclude equipment, capital expenditures, charges for patient care, rental costs, tuition remission, scholarships and fellowships, participant support costs and the portion of each lower tier subaward and subcontract in excess of $25,000.

J. The required technical memorandum titled “Implementation of Research Findings and Products” should (a) provide recommendations on how to best put the research findings/products into practice; (b) identify possible institutions that might take leadership in applying the research findings/products; (c) identify issues affecting potential implementation of the findings/products and recommend possible actions to address these issues; and (d) recommend methods of identifying and measuring the impacts associated with implementation of the findings/products. Implementation of these recommendations is not part of the research project and, if warranted, details of these actions will be developed and implemented in future efforts.

The research team will be expected to provide input to an implementation team consisting of panel members, AASHTO committee members, the NCHRP Implementation Coordinator, and others in order to meet the goals of NCHRP Active Implementation: Moving Research into Practice, available at http://onlinepubs.trb.org/onlinepubs/nchrp/docs/NCHRP_ActiveImplementation.pdf

K. If the team proposes a Principal Investigator who is not an employee of the Prime Contractor, or if the Prime Contractor is proposed to conduct less than 50% of the total effort (by time or budget), then section five of the proposal should include: (1) a justification of why this approach is appropriate, and (2) a description of how the Prime Contractor will ensure adequate communication and coordination with their Subcontractors throughout the project.

L. All budget information should be suitable for printing on 8½″ x 11″ paper. If a budget page cannot fit on a single 8½″ x 11″ page, it should be split over multiple pages. Proposers must use the Excel templates provided in the Information and Instructions for Preparing Proposals for the Transportation Research Board’s Cooperative Research Programs.