Quality Assurance and Specifications for In-Place Recycled Pavements Constructed Using Asphalt-Based Recycling Agents

Pavement recycling offers significant economical savings in reduced material consumption, reduced cost of construction, and reduced user delays. However, there are currently no acceptable rapid quality control/quality assurance (QC/QA) test methods to ensure that the constructed materials comply with commonly specified quality parameters and are ready for surfacing/trafficking. Asphalt-based recycling agents (foamed asphalt or emulsified asphalt) are used in the following pavement recycling processes: cold in-place recycling (CIR), cold central-plant recycling (CCPR), and full-depth reclamation (FDR). These techniques have traditionally been accepted on the basis of moisture content and compaction in the field and strength tests in the laboratory. These tests do not readily lend themselves to assessing the as-constructed quality and ultimate performance of recycled materials, nor do they help determine the proper time that trafficking/surfacing can be applied without causing damage. Many agencies specify a mandatory curing period (ranging from 2 to 14 days) before the recycled layer can be trafficked or surfaced; however, these times are empirically based. If the actual required curing period can be identified, significant construction delays may be avoided. There is a need to develop appropriate test(s), performed on site at the time of construction, that allow an agency to determine the quality of the recycled pavement and its readiness for trafficking/surfacing. This project will develop a new test(s) or modification of an existing test(s) to rapidly assess the in-place quality of the recycled material and compare the output of this method(s) to practices traditionally used to assess quality, develop acceptance criteria, and provide guidelines on time to trafficking/surfacing. Several state departments of transportation (DOTs) and some local government agencies have developed construction specifications for the various forms of in-place recycling. Some of these specifications vary widely from jurisdiction to jurisdiction. Uniform specifications are needed to more easily allow in-place recycling contractors to operate in these various public agencies. Uniform specifications for all types of in-place recycling operations will be a product of this research effort. Many existing in-place recycling specifications are method types of specifications with few QC/QA tests and acceptance criteria. Specifications need to be developed that are aligned to a quality management approach with specific quality control and quality acceptance tests and limits. Development of more end result specifications should be considered as well as warranty/guarantee types of specifications and the inclusion of in-place density requirements and ride quality. Equipment calibration procedures should be considered for inclusion in specifications. The objective of this research is to develop (1) a rapid field-based test(s) for recycled asphalt pavement materials to guide contractors’ quality while providing the transportation agency a basis for acceptance and time to trafficking/surfacing; (2) uniform guide specifications for all forms of in-place recycling; and (3) warranty/guarantee guide specifications for all types of in-place recycling. The following tasks have been identified to complete the work for this project: (1) Conduct a literature search and survey of transportation agencies nationally and internationally to identify current test methodologies used for rapid quality assessment of recycled asphalt pavement materials and summarize the existing practice. (2) Develop new field test(s) or modify an existing test(s) for rapid field assessment of the quality of recycled asphalt pavement materials. Determine if the output from the new or modified test(s) can be related to more traditionally used tests such as unconfined compressive strength, resilient modulus, indirect tensile strength, stability testing, dynamic modulus, etc. (3) Propose and conduct a comprehensive testing program using the identified rapid field test(s), and compare to traditionally used tests, on construction projects with recycled asphalt pavement materials. The testing program must establish test method precision and bias statements as well as acceptance criteria for use with the proposed new field test(s). (4) Develop guide specifications for in-place recycling, including those applicable to projects with warranties or guarantees. (5) Develop a final report and training materials for implementation by agencies. Conduct one train-the-trainer session for the National Cooperative Highway Research Program (NCHRP) project panel and incorporate comments into a final deliverable product. The final technical report shall include a literature review; summary of findings; equipment and test requirements; testing procedure(s), including precision and bias statements; acceptance criteria for the proposed new test(s); and proposed guide specifications. Note: The American Association for State Highway and Transportation Officials (AASHTO) Standing Committee on Research directed that the project panel (1) incorporate problem statement 2017-D-11, “In-Place Recycling Quality Control/Quality Assurance and Specifications,” into the scope of this project, and (2) consider whether any elements of problem statements 2017-D-10 “In-Place Recycling Performance and Life-Cycle Cost Analysis (LCCA),” and 2017-D-09, “In-Place Recycling Project Evaluation and Alternative Selection,” can be accomplished with the available resources.


  • English


  • Status: Proposed
  • Contract Numbers:


  • Sponsor Organizations:

    National Cooperative Highway Research Program

    Transportation Research Board
    500 Fifth Street, NW
    Washington, DC  United States  20001

    American Association of State Highway and Transportation Officials (AASHTO)

    444 North Capitol Street, NW
    Washington, DC  United States  20001

    Federal Highway Administration

    1200 New Jersey Avenue, SE
    Washington, DC  United States  20590
  • Project Managers:

    Harrigan, Edward

  • Start Date: 20160509
  • Expected Completion Date: 0
  • Actual Completion Date: 0
  • Source Data: RiP Project 40809

Subject/Index Terms

Filing Info

  • Accession Number: 01598910
  • Record Type: Research project
  • Source Agency: Transportation Research Board
  • Contract Numbers: 09-62
  • Files: TRB, RiP
  • Created Date: May 8 2016 1:00AM