Procedures and Guidelines for Validating Contractor Test Data

Many state departments of transportation (DOTs) utilize contractor test data in the acceptance process for construction materials. Although federal regulation 23 CFR 637B permits the use of contractor test data for acceptance of construction materials, DOTs are required to validate the data with independent test results. A combination of hypothesis tests (specifically the F- and t-tests) is commonly used to determine if the contractor and DOT test results are from the same statistical population. However, other statistical approaches may provide a better means for evaluating contractor test data and associated risks. There is a need to identify the procedures currently available for validating contractor test data for construction materials and other applications, and develop procedures for use in validating contractor test data for construction materials. These procedures should address the different applications and related issues, such as sample size, minor deviations, and associated risks. Also, there is need to prepare guidelines for the application of these procedures. These procedures and accompanying guidelines should help construction and materials engineers effectively use contractor-performed tests to aid in the quality assurance process and reduce the risk of incorrect acceptance decisions and pay adjustments. The objectives of this research are to (1) recommend procedures for validating contractor test data for construction materials and (2) prepare guidelines for their application. Accomplishment of the project objectives will require at least the following tasks. Phase will (1) Review literature, ongoing research findings, and current practices relevant to the procedures for validating contractor test data, and identify available procedures. (2). Evaluate the procedures identified in Task 1—with consideration to risks and other factors. Identify potential procedures and recommend modifications of existing procedures and/or new procedures that merit evaluation in Phase II. (3). Develop a research plan for work to be executed in Phase II to (a) further evaluate the potential, modified, and new procedures identified in Task 2; (b) identify/develop recommended procedures for validating contractor test data; and (c) prepare guidelines for applying these procedures. (4). Prepare an interim report that documents the research performed in Tasks 1 through 3. Following review of the interim report by the National Cooperative Highway Research Program (NCHRP), the research team will be required to make a presentation to the project panel. Work on Phase II of the project will not begin until the interim report 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. Phase II will: 1. Execute the plan approved in Task 4. Develop the procedures for validating contractor test data and related guidelines. The guidelines shall also address use of the procedures in situations where contractor test data is not validated. (6). Using the procedures developed in Task 5 prepare examples to illustrate use of the procedures for different scenarios. (7). Prepare presentation material in a PowerPoint or other format to facilitate implementation and use of the developed procedures and guidelines. (8). Prepare a final deliverable that documents the entire research effort. The procedures and guidelines shall be prepared as a stand-alone document suitable for consideration and adoption by the American Association of State Highway and Transportation Officials (AASHTO). Proposals have been received. The project panel will meet in January to select a contractor to perform the work.


  • English


  • Status: Proposed
  • Contract Numbers:

    Project 10-100

  • Sponsor Organizations:

    American Association of State Highway and Transportation Officials (AASHTO)

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

    National Cooperative Highway Research Program

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

    Federal Highway Administration

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

    Hanna, Amir

  • Start Date: 20161211
  • Expected Completion Date: 0
  • Actual Completion Date: 0
  • Source Data: RiP Project 41292

Subject/Index Terms

Filing Info

  • Accession Number: 01618756
  • Record Type: Research project
  • Source Agency: Transportation Research Board
  • Contract Numbers: Project 10-100
  • Files: TRB, RiP
  • Created Date: Dec 11 2016 1:00AM