This test method covers the determination of bulk specific gravity (G mb ) of specimens of compacted asphalt mixtures. This method should not be used with specimens that contain open or interconnecting voids or absorb more than 2.0 percent of water by volume. If the specimen contains open or interconnecting voids or absorbs more than 2.0 percent of water by volume, then T 275 or T 331 should be used. The bulk specific gravity (G mb ) of the compacted asphalt mixture may be used in calculating the unit mass of the mixture. Note – The values for bulk specific gravity (G mb ) obtained from T 275 or T 331 may differ. Care should be exercised when comparing test results from T 275 and T 331.