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AASHTO T326 – Standard Method of Test for Uncompacted Void Content of Coarse Aggregate (As Influenced by Particle Shape, Surface Texture, and Grading)


This method describes the determination of the loose uncompacted void content of a sample of coarse aggregate.

When measured on any aggregate of a known grading, void content provides an indication of the aggregate’s angularity, sphericity, and surface texture compared with other coarse aggregates tested in the same grading.

Three procedures are included for the measurement of void content. Two use graded coarse aggregate (standard grading or as-received grading), and the other uses several individual size fractions for void content determinations:

  1. Standard Graded Sample (Method A)
  2. Individual Size Fractions (Method B)
  3. As-Received Grading (Method C)


angularity; coarse aggregate; particle shape; surface texture; void content