Statistical Analysis of HMA Production and Construction Data to Improve Quality Assurance and Acceptance Practices in Idaho

The purpose of this project is to examine discrepancies between contractor-produced and Idaho Transportation Department (ITD)-produced quality control/quality assurance (QC/QA) test results associated with hot mix asphalt (HMA) production and testing. During the year 2017, ITD undertook a forensic study on 13 pre-selected projects to identify any possible discrepancies between ITD-produced and contractor-produced test results. Out of the 77 comparisons (based on comparing six key properties) carried out, only 20 (26%) cases were observed where the contractor-produced and ITD-produced test results were in good agreement with each other; 57 (74%) cases were found where the two data sets did not ‘agree’ with each other (due to differences in mean and/or variances). This emphasized the need to review ITD’s practices related to QC/QA of HMA production and construction data. This research will examine sources of such discrepancies, the significance of any discrepancies present, and also their potential effects on construction costs, maintenance costs, and pavement life with the goal of improving the overall condition of asphalt pavements in the state of Idaho. The primary objective of this proposed project is to identify sources of discrepancies/inconsistencies in HMA production and construction data through extensive statistical analysis. The data to be analyzed will include: (1) Contractor-provided mix design data; (2) data from ITD’s mix design verification efforts; (3) Modifications made to the original mix design through the Contractor’s Job Mix Formula (CJMF); (4) Data from QC testing at the HMA plant (contractor-produced); and (5) QA data obtained during the pavement construction.


  • English


  • Status: Completed
  • Funding: $125000
  • Contract Numbers:

    RP 275

  • Sponsor Organizations:

    Idaho Transportation Department

    P.O. Box 7129, 3311 West State Street
    Boise, ID  United States  83707-1129
  • Project Managers:

    Copeland, Michael

  • Performing Organizations:

    Boise State University, Boise

    Department of Civil Engineering
    ET 201B
    Boise, ID  United States  83725
  • Principal Investigators:

    Mishra, Debakanta

  • Start Date: 20180701
  • Expected Completion Date: 20201231
  • Actual Completion Date: 20210630

Subject/Index Terms

Filing Info

  • Accession Number: 01703600
  • Record Type: Research project
  • Source Agency: Idaho Transportation Department
  • Contract Numbers: RP 275
  • Files: RIP, STATEDOT
  • Created Date: Apr 30 2019 10:39AM