If the depth of moist sand in a cylinder is 15 cm and the depth of the sand when fully inundated with water is 12 cm, what is the bulking of the moist sand?
Correct Answer: D. 0.25
📚 Detailed Explanation: Calculating Bulking from Cylinder Test
Why D (0.25) is correct: The cylinder test for bulking measures the apparent volume increase of moist sand compared to the same sand when fully inundated. When fully submerged, water eliminates surface tension effects, so the sand settles to its “true” packed volume. The ratio of the increase to the inundated depth gives the bulking factor.
Depth of moist sand (Hmoist) = 15 cm
Depth when inundated (Hwet) = 12 cm
Depth when inundated (Hwet) = 12 cm
Bulking = (Hmoist − Hwet) / Hwet
= (15 − 12) / 12
= 3 / 12 = 0.25 = 25%
Cylinder Test for Bulking (IS 2386 Part 3)
| Step | Procedure |
|---|---|
| 1 | Fill graduated cylinder loosely with moist sand to a depth Hmoist |
| 2 | Pour water to fully inundate the sand and measure depth Hwet |
| 3 | Bulking = (Hmoist − Hwet) / Hwet |
| Result | (15−12)/12 = 0.25 = 25% bulking |
- Bulking formula: (Hmoist − Hwet) / Hwet = 3/12 = 0.25 (25%).
- This test gives the bulking fraction used to correct volume batching of moist sand.