**AASHTO T269**:2014 Standard Method of Test for Percent Air Voids in Compacted Dense and Open Asphalt Mixtures.

3.2. Definitions:

3.2.1. air voids (Va)—the pockets of air between the asphalt-coated aggregate particles in a compacted asphalt mixture.

3.2.2. dense asphalt mixture—asphalt mixtures in which the air voids (Va) are less than 10 percent when compacted.

3.2.3. open asphalt mixture—asphalt mixtures in which the air voids are 10 percent or more when compacted.

3.2.3.1. For borderline cases, an asphalt mixture shall be designated as an open asphalt mixture if the calculated percent air voids, based on either Section 6.1 or 6.2. are 10 percent or more.

4. SIGNIFICANCE AND USE

4.1. The percent air voids in an asphalt mixture is used as one of the criteria in the design methods and for evaluation of the compaction achieved on asphalt paving projects.

6. PROCEDURE

6.1. For dense asphalt mixtures, determine the bulk specific gravity (G,b) of the compacted mixture by either T 166. T 275. or T 331. Determine the theoretical maximum specific gravity (Gm,n) in accordance with T 209 on a comparable asphalt mixture to avoid the influence of differences in gradation, asphalt content, etc.

6.2. For open asphalt mixtures, use either oftliefi.!lowing methods:

6.2.1. Automatic Vacuum Sealing Method— Determine the bulk specific gravity (Gmh) of the compacted mixture by T 331. Determine the theoretical maximum specific gravity (Gn,m) in accordance with T 209 on a comparable asphalt mixture to avoid the influence of differences in gradation, asphalt content, etc.

6.2.2. Volwne Method—Determine the density of a regularly shaped specimen of compacted mixture from its dry mass (in grams) and its volume (in cubic centimeters). Obtain the height of the specimen by ASTM D 3549/D 3549M. Measure the diameter of the specimen at Ibur locations, and average the measurements. Calculate the volume of the specimen based on the average height and diameter measurement. Convert the density to bulk specific gravity (Gmh) by dividing by 0.99707 g/cm3 or 997 kgJrn3, the density of water at 25°C (77°F). Determine the theoretical maximum specific gravity (Gmm) in accordance with T 209 on a comparable asphalt mixture to avoid the influence of differences in gradation, asphalt content, etc.

For reference purposes, determine both the bulk specific gravity (Gmh) and the theoretical maximum specific gravity on portions of the same sample of compacted asphalt mixture.AASHTO T269 pdf download.