During the fall of 1995, FHWA's Office of Acquisition Management signed a new 5-year cooperative agreement which extends one of the Office of Research and Development's longest partnerships. Since 1965, FHWA, 52 State highway agencies, and two other governmental agencies have jointly financed the basic operations of the AASHTO Materials Reference Laboratory (AMRL).
The AMRL was established to promote adherence to standards in the testing
of construction materials, particularly by the State and FHWA laboratories.
The AMRL staff inspects laboratories at roughly 24-month intervals -- and
regularly distributes proficiency samples -- to assess each laboratory's capabilities
for performing standard tests on soils, aggregates, asphalts, and mixtures
of these materials. The AMRL also uses the resources of a parallel organization,
the Cement and Concrete Reference Laboratory (CCRL), to evaluate laboratory
performance on tests on cement and concrete.
Results of AMRL assessments provide FHWA with its only independent evaluation of States' (and its own laboratories') testing prowess. FHWA's division offices rely on the results of the AMRL program before approving the expenditure of Federal funds for highway construction. As a side benefit, AMRL evaluations improve the quality of testing for non-Federal construction within each State. With new Federal regulations permitting contractors' test results to be used much more widely in the States' quality assurance decisions, AMRL will need to further expand its programs.
The organization's staff, which operates out of laboratory space at the National Institute of Standards and Technology (NIST) in Gaithersburg, Maryland, conducted inspections of 295 laboratories during the most recent 24-month tour and distributed more than 6,000 proficiency samples each year. The AMRL also provides the technical support for the AASHTO Accreditation Program, which has accredited over 200 laboratories across the United States.