ASTM D6752/D6752M-23 PDF

SIGNIFICANCE AND USE 4.1 The results obtained from this method can be used to determine the unit weight of compacted asphalt mixtures, and in conjunction with Test Method D3203/D3203M, to obtain percent air voids. These values in turn may be used in determining the relative degree of compaction. 4.2 Since specific gravity has no units, it must be converted to density in order to do calculations that require units. This conversion is made by multiplying the specific gravity at a given temperature by the density of water at the same temperature. 4.3 This method can be used for 100 mm [4 in.] and 150 mm [6 in.] diameter cylindrical as well as cubical asphalt mixture specimens to correct for inconsistencies in sample weight determinations resulting from drainage of water from samples and inaccuracy in saturated surface dry weight of absorptive coarse and open-graded mixes. Asphalt mixes such as stone matrix asphalt (SMA), porous friction course, and coarse-graded mixes with significant surface texture and interconnected voids can be tested with this method. Follow manufacturer recommendation for appropriate bag sizes to be utilized with cubical and abnormally shaped samples.4 Note 1: 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 test method covers the determination of bulk specific gravity of compacted asphalt mixtures by the vacuum sealing method. 1.2 This method can be used for compacted cylindrical and cubical laboratory and field asphalt mixture specimens. 1.3 The bulk specific gravity of the compacted asphalt mixtures may be used in calculating the unit weight of the mixture. 1.4 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in nonconformance with the standard. 1.5 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. 1.6 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. 1.7 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.