In the SSD cone test, if the sand slumps on the first trial, what is the correct procedure?

• A. Increase drying temperature to 140 °F and dry for additional 15 minutes.
• B. Let it dry without adding moisture.
• C. Add a few milliliters of moisture and allow water to soak into the sample for 30 minutes, and then repeat the drying process.
• D. Discard the sample and start over.

Answer: (C)

When you’re performing the SSD cone test, the goal is to have the sand at saturated surface-dry conditions so it can form a stable cone. If the sand slumps on the first trial, that means it’s too dry to hold its shape. The correct fix is to add a small amount of moisture and let it soak in so the water distributes evenly and the grains have just enough cohesion to support the cone. After about 30 minutes of soaking, you dry the sample again to reach SSD and then repeat the cone test. This approach restores the proper moisture balance without over-drying or over-wetting, ensuring accurate and reproducible results.