Precision Estimates of AASHTO T 304, AASHTO T 96, and AASHTO T 11 and Investigation of the Effect of Manual and Mechanical Methods of Washing on Sieve Analysis of Aggregates. Research Results Digest 389

摘要

Under NCHRP Project 10-87, the AASHTO Materials Reference Laboratory (AMRL) is conducting a multi-phase research project to improve estimates of precision in AASHTO test methods for a wide range of construction materials. AMRL has an extensive database of test results for the broad range of construction materials collected through its Proficiency Sample Program (PSP) that are used for developing precision estimates. Laboratories participating in the AMRL PSP receive annual or biannual shipments of paired proficiency samples, which are tested according to specified AASHTO test methods. The results of the testing are returned to AMRL for analysis, summarization, and reporting back to the laboratories. The number of participants in the AMRL PSP program is sufficiently large enough to ensure a statistically sound basis for determination of estimates of precision for standard test methods.