Standard Active Last Updated: Mar 19, 2020
ASTM D7981-20

Standard Practice for Compaction of Prismatic Asphalt Specimens by Means of the Shear Box Compactor

Significance and Use

5.1 Asphalt prisms compacted with the shear box compactor can be used to obtain specimens for further testing, including bulk specific gravity following Test Methods D6752/D6752M and D2726/D2726M; dynamic modulus following AASHTO T 342; dynamic modulus, flow number, and flow time following AASHTO T 378; and fatigue performance characteristics following AASHTO T 321.

5.2 Specimens to perform other standard tests could also be obtained, as long as their volume is contained within the volume of a prism having maximum width, length, and height (W × L × H) of 150 mm, 450 mm, and 185 mm, respectively. The maximum prism height depends on the mix type, the target air voids, and the equipment limitations.

Note 1: The aggregate orientation in the samples produced by this method may be different from samples produced by other laboratory compaction methods. This should be considered when comparing mechanical test results from different compaction methods.

Note 2: The quality of the results produced by this standard are dependent on the competence of the personnel performing the procedure and the capability, calibration, and maintenance of the equipment used. Agencies that meet the criteria of Specification D3666 are generally considered capable of competent and objective testing, sampling, inspection, etc. Users of this standard are cautioned that compliance with Specification D3666 alone does not completely ensure reliable results. Reliable results depend on many factors. Following the suggestions of Specification D3666 or some similar acceptable guideline provides a means of evaluating and controlling some of those factors.

Scope

1.1 This practice covers the fabrication of prismatic specimens of asphalt mixture using the shear box compactor (SBC). Compacted specimens are suitable for volumetric and physical property testing. This standard practice should not be used for acceptance or rejection of a material or for purchasing purposes.

1.2 Units—The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard with exception of degrees (°) where angle is specified.

1.3 The text of this standard references notes and footnotes which provide explanatory material. These notes and footnotes (excluding those in tables and figures) shall not be considered as requirements of the standard.

1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.

1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

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Details
Book of Standards Volume: 04.03
Developed by Subcommittee: D04.20
Pages: 5
DOI: 10.1520/D7981-20
ICS Code: 93.080.20