The AASHTO Accreditation Program (AAP) was established in 1988 as a means of formally recognizing the competence of testing laboratories to perform specific tests on construction materials. AAP is a voluntary program that is available to all testing laboratories including government, commercial, university, and research facilities. There are nearly 1,500 individual laboratories that are currently accredited through AAP, making it the largest accrediting body of construction materials testing laboratories. AAP utilizes laboratory assessment and proficiency sample services provided by the AASHTO Materials Reference Laboratory (AMRL) and the Cement and Concrete Reference Laboratory (CCRL
). AMRL provides administrative coordination and technical support for AAP.
AASHTO accreditation is important in many ways. Accredited laboratories can demonstrate that their testing services not only conform to specific national and international standards, but are also of the highest quality. Accreditation can also enhance a customer’s confidence in the testing provided by the laboratory. Accredited laboratories have been subjected to vigorous on-site, third party assessments. During these assessments, each test method is demonstrated in its entirety by the laboratory’s technical staff, and the testing apparatus associated with each test is evaluated. The assessment also includes a thorough review of the laboratory’s quality management system, including records of technician training and competency evaluations as well as equipment calibration and check records. Additionally, a detailed review of all accreditation requirements, including participation in the AMRL and CCRL proficiency sample programs, is conducted for each accredited laboratory at least once per year.
AASHTO will accredit laboratories for the following fields of testing: asphalt cement, hot mix asphalt, emulsified asphalt, aggregate, soil, sprayed fire-resistive materials (SFRM), Portland cement concrete, hydraulic cement, unit masonry, and metals. Accreditation is available for the specific AASHTO and ASTM test methods that were included in the scope of the laboratory’s most recent AMRL and/ or CCRL on-site assessment(s).
The AAP Procedures Manual
includes specific requirements for laboratories that wish to be accredited. Each accredited laboratory must have a quality management system that meets the requirements of AASHTO R18
. Accredited laboratories must also receive regularly scheduled on-site assessments by AMRL and/or CCRL, and actively participate in the applicable proficiency sample programs provided by these agencies. All nonconformities noted on the laboratory’s most recent assessment report(s) must be adequately resolved within 90 days of the issuance of the final report. Laboratories that receive poor ratings for proficiency sample testing are required to conduct a root cause analysis to determine the reason(s) for the low ratings.
Directory of Accredited Laboratories
The AMRL website includes an electronic directory of accredited laboratories
. The directory includes the following information for each accredited laboratory: laboratory name, address, contact information, accredited test methods, and date(s) of initial accreditation for each testing field. Website users can search for specific laboratories by city or state/country using this directory. The directory is updated frequently and is the sole source for current accreditation information.