State departments of transportation (DOTs), as part of their routine practice, employ quality assurance (QA) procedures based on certifications, inspections, sampling, and testing in their acceptance process for highway pavement construction. The QA requirements are generally in accordance with the federal regulations for construction QA procedures (23 CFR, Part 637B) as well as the recommendations of the Federal Highway Administration (FHWA) and the American Association of State Highway and Transportation Officials (AASHTO) for QA programs. However, one thing generally absent from these programs or plans is the utilization of nondestructive testing (NDT) methods in the QA process.
Several studies in recent years have identified the potential advantages of incorporating NDT methods into the QA process for highway pavement construction. These NDT methods are considered to provide an “added value” in the QA process since they potentially allow for (1) quickly assessing product uniformity in real-time as construction progresses; (2) identifying potential defects during construction to allow for timely corrective actions; (3) more frequent inspecting, testing, and replicating without the damaging effects of coring and other destructive testing; and (4) minimizing testing and inspection costs, while improving construction quality. For example, for concrete, the NDT methods can evaluate concrete properties, uniformity, honeycombing, segregation, and cover depth as well as detect reinforcement and dowel bar location and characteristics. Similarly, for asphalt mixtures, the NDT methods can assess properties and conditions such as density, stiffness, thickness, and thermal uniformity. However, despite their high potential and usefulness, the transition of NDT methods from research and forensic investigation to DOTs’ QA process has been rather limited. This is because of the relative complexity of some NDT technologies, inadequate training of QA technicians and inspectors in their use, reluctance to adopt a new technology, and a lack of guidance on how to incorporate the NDT technologies into the overall QA program.
The objective of this research is to develop a guidance manual to assist state DOTs in selecting and incorporating NDT methods into their QA programs for highway pavement construction.
Proposers are required to provide a detailed research plan for accomplishing the project objective and producing the deliverables required by each phase of the project. The research plan needs to be realistic to ensure that it can be accomplished within the constraints of contract funds and time. Proposers are expected to present their current thinking in sufficient detail to demonstrate their understanding of the issues needing resolution and the soundness of their approach to meeting the research objective. The proposed work is to be divided into tasks with sufficient details of the work to be performed in each task.
The research plan shall be executed in two phases and comprise, at a minimum, the following tasks:
Task 1. Perform a literature review and a scan of current and emerging NDT technologies and practices to provide an overview of potential NDT QA procedures for use in highway pavement construction applications.
Task 2. Recommend, with adequate justification, NDT methods identified as good candidates for inclusion in the quality control (QC) and acceptance testing program for highway pavement construction.
Task 3. Provide a work plan aimed at developing guidance for incorporating NDT methods for various highway pavement construction applications into the state DOTs’ QA programs. These NDT methods should be suitable for inclusion at various stages in the QA process used by the contractors and/or in the acceptance process used by the state DOTs.
Task 4. Provide an outline of the guidance manual based on the findings and considerations from the above tasks. The guidance manual will be developed in Phase II of the project.
Task 5. Prepare an interim report detailing the outcomes of all of the above tasks.
Phase I shall be completed within 6 months (including 1 month for the NCHRP review) at a cost not exceeding $60,000. Approval of the Phase II work plan by the NCHRP is a prerequisite for proceeding to Phase II.
Task 6. Develop a guidance manual, providing an overview of the NDT methods applicable to highway pavement construction along with a brief description of their operating principles, detection/measurement capabilities, potential benefits, and limitations and drawbacks. The objective of the manual is not to recommend any specific NDT method but rather illustrate the features and capabilities of various NDT methods and their applicability at various stages (for example, process control, QC, and acceptance) in the QA process for highway pavement construction. The guidance for state DOTs will include:
1. Development and implementation of NDT-based QA procedures
2. Assessing appropriate control and specification limits
3. Technician training and certification
4. Testing and analysis time
5. Testing costs
6. Setting up of pilot projects before full-scale implementation
7. Lot and sublot size considerations
8. Data management practices
9. Independent assurance (IA) procedures
10. Dispute resolution process
11. Cost/benefits analysis assessment for different applications and project sizes/scopes.
Guidance on how to gain buy-in from state DOTs and construction industry should also be provided.
Task 7. Upon approval of the draft guide by the NCHRP, prepare a final guide as an AASHTO recommended practice and develop a step-by-step plan for its implementation.
Task 8. Prepare a final report that documents results, summarizes findings, draws conclusions, and makes recommendations.
Task 9. Conduct at least two webinars for state DOT, FHWA, and industry personnel and make a presentation before the relevant AASHTO committee.
Phase I deliverables shall include, at a minimum:
An interim report consisting of the following items:
- A critical literature review and a scan of state DOTs’ current practice to:
a. Provide an overview of the current and emerging NDT QA procedures in use in highway pavement construction.
b. Discuss current knowledge and practice of the NDT methods applicable to highway pavement construction.
c. Identify NDT methods (including new and emerging) deemed suitable for inclusion in the state DOTs’ QA programs for highway pavement construction.
- Recommendations for NDT technologies and methods for highway pavement construction QA programs for inclusion in the guidance manual.
- An outline of the guidance manual, to be developed in Phase II.
- A proposed work plan for Phase II.
Note: The contractor shall meet with the NCHRP within 1 month of the submission of the interim report. NCHRP approval of the Phase II work plan is required before proceeding with Phase II tasks.
Phase II shall include, at a minimum, the following deliverables and activities:
- A final report that documents results, summarizes findings, draws conclusions, and makes recommendations.
- A guidance manual for state DOTs, based on the findings of Phase I work and developed as suggested in Task 6 of the research plan. The guide, intended to be an AASHTO recommended practice, will be prepared in an AASHTO manual format.
- A plan for implementing the final guide for adoption by state DOTs as an AASHTO recommended practice.
- Webinars for state DOT, FHWA, and industry personnel. Presentations at the AASHTO committees relevant to materials, pavements, and bridges.
- A draft TRNews article highlighting the products of this research and their implementation.
A. The proposal, including all appendices, shall not exceed 50 single-spaced pages written in 12-point font or larger; the Research Plan, Item 4 of the proposal, shall not exceed 20 single-spaced pages.
B. Proposals should include a task-by-task breakdown of labor hours for each staff member as shown in Figure 4 in the brochure, "Information and Instructions for Preparing Proposals" (http://onlinepubs.trb.org/onlinepubs/crp/docs/ProposalPrep-July2019.pdf). 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.
C. The NCHRP is a practical, applied research program that produces implementable products addressing problems faced by transportation practitioners and managers. The benefits of NCHRP research are realized only when the results are implemented in state DOTs and other agencies. Implementation of the research product must be considered throughout the process, from problem statement development to research contract and beyond completion of the research. Item 4(c), "Anticipated Research Results," must include the following: (a) the "product" expected from the research, (b) the audience or "market" for this product, (c) a realistic assessment of impediments to successful implementation, and (d) the institutions and individuals who might take leadership in deploying the research product. The project panel will develop and maintain an implementation plan throughout the life of the project. 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.
D. Item 5 in the proposal, "Qualifications of the Research Team," must include a section labeled "Disclosure." Information relevant to the NCHRP's need to ensure objectivity and to be aware of possible sources of significant financial or organizational conflict of interest in conducting the research must be presented in this section of the proposal. For example, under certain conditions, ownership of the proposing agency, other organizational relationships, or proprietary rights and interests could be perceived as jeopardizing an objective approach to the research effort, and proposers are asked to disclose any such circumstances and to explain how they will be accounted for in this study. If there are no issues related to objectivity, this should be stated.
E. Proposals are evaluated by the NCHRP staff and project panels consisting of individuals collectively very knowledgeable in the problem area. Selection of an agency is made by the project panel 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.
Note: The proposer's approach to inclusion and diversity as well as participation by Disadvantaged Business Enterprises should be incorporated in Item 12 of the proposal.
F. 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 Academies of Sciences, Engineering, and Medicine. 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 Academies of Sciences, Engineering, and Medicine. 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.