Which statement about SSD conditioning is true?

• A. This procedure requires approximately 1 kg of oven dried sand to begin the test.
• B. Shaking the basket to release any entrapped air as it is placed in the water bath is not recommended due to potential sample loss.
• C. The specified time period for the sand to soak in the water is 24-48 hours.
• D. When performing the cone test to check the condition of the sand, permit the tamper to fall freely from 50 mm over the top of the sand.

Answer: (A)

SSD conditioning centers on bringing the aggregate to a saturated surface-dry state by displacing entrapped air with a measured amount of dry filler. Using approximately 1 kg of oven-dried sand provides a standardized, sufficient quantity to fill the pore spaces and push out trapped air without introducing moisture or overwhelming the sample. This fixed starting mass is what keeps conditioning reproducible from one lab to another and ensures the moisture and surface characteristics of the aggregate are assessed on a consistent basis. The other statements don't align with how SSD conditioning is typically performed: they either describe steps or timeframes not part of the standard procedure or refer to tests (like a cone test with a tamper) that aren’t involved in conditioning the aggregate to SSD.