For coarse aggregate samples, the requirement is that the sample remains on the suspension for at least 60 minutes and the immersed mass is recorded.

For coarse aggregate samples, the requirement is that the sample remains on the suspension for at least 60 minutes and the immersed mass is recorded.

• A. True
• B. Only if the sample is dry
• C. False
• D. 30 minutes

Answer: (C)

Understanding how coarse aggregate specific gravity and absorption are determined helps explain why this statement isn’t correct. In this test, you determine how heavy the aggregate is in air, in a saturated surface-dry state, and when submerged in water. The key is ensuring the sample is properly saturated and that its immersed (submerged) mass is measured under stable, fully submerged conditions so buoyancy is accurate. The requirement to keep the sample on a suspension for a fixed 60 minutes does not match the standard procedure; the soaking times are governed by achieving saturated surface-dry conditions and full immersion, typically requiring longer soaking (often around 24 hours) rather than a 60-minute limit. So the notion that the sample must stay suspended for at least 60 minutes before recording the immersed mass is not correct.

Understanding how coarse aggregate specific gravity and absorption are determined helps explain why this statement isn’t correct. In this test, you determine how heavy the aggregate is in air, in a saturated surface-dry state, and when submerged in water. The key is ensuring the sample is properly saturated and that its immersed (submerged) mass is measured under stable, fully submerged conditions so buoyancy is accurate. The requirement to keep the sample on a suspension for a fixed 60 minutes does not match the standard procedure; the soaking times are governed by achieving saturated surface-dry conditions and full immersion, typically requiring longer soaking (often around 24 hours) rather than a 60-minute limit. So the notion that the sample must stay suspended for at least 60 minutes before recording the immersed mass is not correct.