Category Archives: AASHTO

Technical Bulletin –  20210118

Deformation Rate & Sprocket Arrangement Pine slowed the specimen deformation rate of the Pine AF850 Test Press by installing the same size sprockets on the motor and the jack to achieve a 1:1 ratio between the motor and the jack because it was found not to comply with the specimen deformation rate of 50 ±…

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Angle Matters

I know that AASHTO T312 requires a gyratory compactor to operate at an internal angle of gyration of 1.16° ±0.02°.  But, what impact does variation in this angle really have? A low angle of gyration leads to less compaction and higher air voids.  A 0.1° drop in the angle of gyration lowers the bulk specific…

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AASHTO Implements ISO 17025 Requirements

AASHTO R18 (2016) Sections 6.2.1.5 and 6.2.1.5.1 include a new requirement—ISO/IEC 17025-certified calibration of measurement standards not manufactured by the calibrating laboratory.  The 2017 edition of R18 reportedly changes Section 6.2.1.5.1 to exclude only proprietary measurement standards from the ISO-certified calibration requirement.  The purpose of this requirement is to build confidence into test results because…

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2016 AASHTO SOM Meeting

Todd Arnold, Division Manager, will attend the AASHTO Subcommittee on Materials Meeting July 31-August 4.  The Subcommittee is responsible for the development of materials and test standards utilized by all of AASHTO member departments.  Todd Arnold along with materials engineers and technical experts from member departments work for consensus on these important documents.  Industry and academia participation…

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