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The AASHTO Accreditation Program: Serving the HMA Industry



Robert A. Lutz, J B. Hewston, D Savage, Peter Spellerberg


The American Association of State Highway and Transportation Officials (AASHTO) has been accrediting hot mix asphalt testing laboratories under the AASHTO Accreditation Program (AAP) since 1988. Laboratories must satisfy many quality system criteria, as well as participate in the AASHTO Materials Reference Laboratory (AMRL) on-site assessment and proficiency sample programs, in order to receive accreditation from AASHTO. The number of laboratories accredited by AASHTO for HMA has grown from just a few in 1988 to more than 200 in 1998. Satisfying the requirements of the growing list of agencies specifying accreditation, often in various forms, made the first ten years a challenging experience for both the AAP and its accredited laboratories. AMRL and the testing laboratories involved in the AAP have dealt not only with multiple quality system standards (AASHTO, ASTM and ISO) but also with their evolving criteria as well.The development of the National Cooperation for Laboratory Accreditation (NACLA) will present more demands as the AAP moves into its second decade as an accrediting body. Analysis of AMRL proficiency sample data indicates that accreditation is beneficial to the construction industry and that the AAP meets its objective of promoting uniformity in the testing of construction materials. This paper describes the scope of the AASHTO Accreditation Program, its general accreditation criteria and the status of the program. Experiences and observations from the first ten years of the program are summarized. Examples of hot mix asphalt related tests in which the repeatability and reproducibility of accredited laboratories is noticeably better than nonaccredited laboratories are provided. Possible explanations for this conclusion are examined. Lastly, this paper explores the future of the AASHTO Accreditation Program and offers some recommendations for change.
Proceedings Title
Proceedings of the ASTM D4 Symposium on Hot Mix Asphalt Construction: Certification and Accreditation Programs
Conference Dates
December 1, 1998
Conference Location
Conference Title
Hot Mix Asphalt Construction Symposium


accreditation, asphalt, building technology, laboratory testing, quality


Lutz, R. , Hewston, J. , Savage, D. and Spellerberg, P. (2017), The AASHTO Accreditation Program: Serving the HMA Industry, Proceedings of the ASTM D4 Symposium on Hot Mix Asphalt Construction: Certification and Accreditation Programs, Undefined (Accessed April 13, 2024)
Created February 19, 2017