Consistency Limit Tests

• Construction
• Further Education (Key Stage 5)

Consistency limit tests 

CIV142 Geology & Soil Mechanics

Learning Outcomes

By the end of this lesson you will be able to:

• Describe the terms Liquid, Plastic and Shrinkage Limit
• Describe and calculate the Plasticity, Liquidity and Consistency Indexes
• Determine the Volume Change Potential of a Soil
• Calculate from results the Liquid and Plastic limits of a soil
• Classify a fine soil

Which of these best describes
'Liquid Limit'?

1. The water content at which the soil stops acting as a plastic and starts acting as a solid
2. The water content at which the soil no longer displays permanent deformation and simply fractures when shearing stresses are applied
3. A cohesive soil with an extremely high water content – behaves as a liquid with continual deformation
4. The water content at which the soil stops acting as a liquid and starts acting as a plastic solid

Which of these best describes
'Plastic Limit'?

1. A cohesive soil that behaves as a plastic and displays permanent deformation
2. The water content at which the soil no longer displays permanent deformation and simply fractures when shearing stresses are applied
3. A cohesive soil with an extremely high water content – behaves as a liquid with continual deformation
4. The water content at which the soil stops acting as a liquid and starts acting as a plastic solid

A soil has a Plastic Limit of 22% and a Liquid limit of 48%, what is it's Plasticity Index?

1. 70%
2. 26%
3. 24%
4. 2.2%

Consistency limit tests on a sample of soil indicate a Plasticity Index of 45%, with 95% passing a 425 micron sieve.
What is it's Volume Change Potential?

1. 50% - High
2. 43% - High
3. 37% - Medium
4. 18% - Low

A soil has a natural water content of 28%, a Plastic limit of 19% and a Liquid Limit of 55%. Calculate it's Liquidity Index.

1. 0.25
2. 0.36
3. 0.48
4. 0.63

Which of these best describes
'Shrinkage Limit'?

1. A cohesive soil that shrinks in volume with a reduction in water content
2. The water content at which a soil exhibits no further change in volume with decreasing water content
3. A cohesive soil in which it's shrinkage is limited to the volume of the soil being sampled.
4. The water content at which a soil continues to shrink in volume with decreasing water content

A soil has a natural water content of 28%, a Plastic limit of 19% and a Liquid Limit of 55%. Calculate it's Consistency Index.

1. 0.37
2. 0.56
3. 0.62
4. 0.75

Learning Outcomes

By the end of this lesson you will be able to:

• Describe the terms Liquid, Plastic and Shrinkage Limit
• Describe and calculate the Plasticity, Liquidity and Consistency Indexes
• Determine the Volume Change Potential of a Soil
• Calculate from results the Liquid and Plastic limits of a soil
• Classify a fine soil