The maximum bulking of sand is likely to occur at a moisture content of
- A5%Correct
- B8%
- C11%
- D15%
Solution
Concept
Thin water films around sand grains push them apart and increase volume. The increase is largest at about 4-6% moisture.
Formula
Bulking (%) = (hdamp - hsaturated) / hsaturated × 100
Step-by-step solution
1. Dry sand shows no bulking. 2. As moisture increases, water films form around the particles and the volume increases. 3. Maximum bulking (about 20-40%) happens at about 4-6% moisture content. 4. With more water, the films join and bulking reduces. Fully saturated sand shows almost no bulking. 5. From the options, 5% is the closest. So the answer is A.
Explanation
Moist sand occupies more volume than dry sand because of water films around the grains. Bulking is maximum at about 4-6% moisture. Fine sand bulks more than coarse sand.
Why the other options are wrong
8%: past the usual peak, so bulking starts to reduce. 11% and 15%: films join and bulking falls a lot. It becomes nearly zero at saturation.
Shortcut
Max bulking near 5% moisture. Zero bulking for dry and saturated sand.
Common mistake
Thinking that more water always gives more bulking.
Correct answer: A) 5%