Engineering Materials·MCQ explained

Pick up the correct statement from the following regarding bulking of sand:

Try it first: pick an option, then read the explanation.

Correct answer: D. All options are correct

Detailed Explanation: Three Correct Statements on Sand Bulking

Why D (All options correct) is correct:

Verification of Each Statement

StatementVerdictDetail
A. 5–6% moisture → 18–38% bulkingCorrectPeak bulking occurs around 4–6% moisture; finer sands can bulk up to 38%
B. Fine sand bulks more than coarseCorrectFiner particles have larger specific surface area → more water film per unit volume → greater bulking
C. >10% moisture → bulking starts decreasingCorrectExcess water floods voids and “drowns” the surface tension effect; particles settle closer

Bulking vs. Moisture Content (Typical Behaviour)

Moisture Content (%)Fine Sand Bulking (%)Coarse Sand Bulking (%)
0 (dry)00
2~15~8
4–6 (peak)25–3815–20
10~15 (decreasing)~8 (decreasing)
Saturated/submerged~0~0
  • All three statements accurately describe bulking behaviour — answer is All of these.