Although the Casagrande test is widely used across North America, the fall cone test is much more prevalent in Europe due to being less dependent on the operator in determining the Liquid Limit.
12.
The test method also allows running the test at one moisture content where 20 to 30 blows are required to close the groove; then a correction factor is applied to obtain the liquid limit from the moisture content.
13.
The undrained shear strength of remolded soil at the liquid limit is approximately 2 kPa . The Plastic Limit is the water content below which it is not possible to roll by hand the soil into 3 mm diameter cylinders.
14.
When the LI is 1, remolded soil is at the liquid limit and it has an undrained shear strength of about 2 kPa . When the soil is at the plastic limit, the LI is 0 and the undrained shear strength is about 200 kPa.
15.
The "'Plasticity Index "'of a particular soil specimen is defined as the difference between the Liquid Limit and the Plastic Limit of the specimen; it is an indicator of how much water the soil particles in the specimen can absorb, and correlates with many engineering properties.
