BACKGROUND: 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.
OBJECTIVES: The objectives of this research were to (1) recommend procedures for validating contractor test data for construction materials and (2) prepare guidelines for their application. .