Question

According to standard test method ASTM D-4318, the moisture content (the liquid limit of soil) is determined by Casagrande’s liquid device, at which a groove closure of _______ occurs at _____ blows.

1. 11.7 mm, 20
2. 12.7 mm, 20
3. 11.7 mm, 25
4. 12.7 mm, 25

Answer 1

Correct Answer - Option 4 : 12.7 mm, 25

Explanation:

According to standard test method ASTM D-4318, the moisture content (the liquid limit of soil) is determined by Casagrande’s liquid device, at which a groove closure of 12.7 mm occurs at 25 blows.

Liquid limit:

• Liquid limit is defined as the minimum water content at which soil has a tendency to flow.
• At liquid limit soil posses from the liquid stage of consistency to the plastic stage of consistency and vice versa.
• All soils at liquid limit possess the same negligible shear strength of 2.7 kN/m2, which can be just measured.
• Liquid limit is found out by the following two methods:
  • Cassagrande's apparatus
  • Cone penetration test