Field identification — Which observation most reliably indicates good quality cement during a quick site check?

Introduction / Context:
On construction sites, quick checks help identify obviously defective cement. While full lab tests are definitive, simple field observations can flag moisture-damaged or adulterated cement before use.

Given Data / Assumptions:

• Ordinary Portland-type cement stored properly.
• Simple, qualitative checks only.

Concept / Approach:
Fresh cement should be free-flowing, cool to the touch, and sink in water, dispersing without floating. Floating or lumping can indicate excessive aeration, moisture uptake, or partial carbonation/hydration.

Step-by-Step Solution:
Visual and tactile check: uniform greenish-grey color and smooth feel are typical of good cement.Water test: a handful should sink and disperse rather than float.Therefore the most reliable single indicator here is sinking in water.

Verification / Alternative check:
IS/ASTM guides mention simple field checks including “feel,” absence of lumps, and sink test as quick screens.

Why Other Options Are Wrong:
Not greenish grey: good cement is typically greenish grey; saying “not” is misleading.Feels rough: fresh cement generally feels smooth, not gritty.Hard lumps: indicate moisture ingress and deterioration.Cool feel can occur but is less decisive than the sink-and-disperse behavior.

Common Pitfalls:
Relying solely on color; brand and composition can vary slightly.

Final Answer:
A handful thrown into a bucket of water does not float (it sinks and disperses)