Which statement about SSD conditioning is true?

Which statement about SSD conditioning is true?

• A. Samples dried past the SSD condition must be immersed in water for 30 minutes prior to resuming the process of surface-drying.
• B. A current of warm air may be used to assist getting the sand to an SSD condition.
• C. The sample is covered with water either by complete immersion or by adding approximately 6 % moisture.
• D. Shaking the basket to release any entrapped air as it is placed in the water bath is not recommended due to potential sample loss.

Answer: (A)

The key idea is how to get and maintain the saturated surface-dry (SSD) condition for aggregate used in asphalt processes. SSD means the pores are filled with water but the surface isn’t wet, so the material is neither fully dry nor actively waterlogged. If you happen to dry the sample beyond SSD (oven-dry), the correct way to bring it back to SSD is to immerse it in water for about 30 minutes and then resume surface-drying. This restores the proper moisture state so measurements like absorption and specific gravity aren’t distorted by being too dry or too wet. So this option is correct because it matches that re-wetting step to return to SSD after overs drying. The other ideas don’t fit the standard SSD approach: using warm air would dry more, not re-wet to SSD; simply covering with water or aiming for a fixed moisture percentage doesn’t achieve the SSD surface condition; and preventing air release during immersion isn’t aligned with how you ensure complete wetting of internal pores.

The key idea is how to get and maintain the saturated surface-dry (SSD) condition for aggregate used in asphalt processes. SSD means the pores are filled with water but the surface isn’t wet, so the material is neither fully dry nor actively waterlogged. If you happen to dry the sample beyond SSD (oven-dry), the correct way to bring it back to SSD is to immerse it in water for about 30 minutes and then resume surface-drying. This restores the proper moisture state so measurements like absorption and specific gravity aren’t distorted by being too dry or too wet.

So this option is correct because it matches that re-wetting step to return to SSD after overs drying. The other ideas don’t fit the standard SSD approach: using warm air would dry more, not re-wet to SSD; simply covering with water or aiming for a fixed moisture percentage doesn’t achieve the SSD surface condition; and preventing air release during immersion isn’t aligned with how you ensure complete wetting of internal pores.