Quick Answer: What Does Liquid Limit Tell You?

What is the purpose of the liquid limit test?

Atterberg limits tests establish the moisture contents at which fine-grained clay and silt soils transition between solid, semi-solid, plastic, and liquid states..

What does the plastic limit tell you?

The Liquid Limit (LL or wLL), also known as the upper plastic limit, is the water content at which the soil changes from the liquid state to a plastic state. It is the minimum moisture content at which a soil flows upon application of very small shear force.

What is the significance of Atterberg limits?

This is very important when trying to build with or build on these type of materials. The two commonly determined Atterberg Limits represent the moisture contents at which a specific soil’s behavior changes from solid to plastic (Plastic Limit) and from plastic to liquid (Liquid Limit).

How do you find the liquid limit?

Calculate the liquid limit from only one soil sample test by dividing the number of blows by 25, raising the result to the power of 0.121 and multiplying by the percent water content.

Can you have a negative plasticity index?

Yes 🙂 it can have have a negative value. A negative liquidity index means that the soil is drier that the plastic limit. It merely describes the moisture condition of a soil with respect to its index limits. It shows in what part of its plastic range a given sample of soil lies.

How do you find the plastic limit and liquid limit?

Calculate the plastic limit wp by dividing the “weight of moisture” by the “dry weight of sample” and multiply by 100. Plasticity Index (Ip) of a soil is the numerical difference between its Liquid Limit and its Plastic Limit.

What is a plasticity?

Plasticity, ability of certain solids to flow or to change shape permanently when subjected to stresses of intermediate magnitude between those producing temporary deformation, or elastic behaviour, and those causing failure of the material, or rupture (see yield point).

What is liquid limit plastic limit and shrinkage limit?

There are three important Atterberg limits: shrinkage limit (SL), plastic limit (PL), and liquid limit (LL). The shrinkage limit is the water content at which the volume of the soil starts to increase. It is also at the point where the soil is 100% saturated.

What is a good plasticity index?

It indicates the fineness of the soil and its capacity to change shape without altering its volume. A high PI indicates an excess of clay or colloids in the soil. Its value is zero whenever the PL is greater or equal to the LL. The plasticity index also gives a good indication of compressibility (see Section 10.3).

What is liquid limit in soil mechanics?

The liquid limit is the moisture content at which the groove, formed by a standard tool into the sample of soil taken in the standard cup, closes for 10 mm on being given 25 blows in a standard manner. At this limit the soil possess low shear strength.

What is a high liquid limit?

A high liquid limit normally indicates a high compressibility and a high shrinkage/swelling potential. A high-plasticity index Ip generally results in a low shear strength. A low Ip means that a soil used as foundation will change significantly in consistency even with a small change in water content.

What is Atterberg limit of soil?

The Atterberg limits are a basic measure of the critical water contents of a fine-grained soil: its shrinkage limit, plastic limit, and liquid limit. Depending on its water content, a soil may appear in one of four states: solid, semi-solid, plastic and liquid.

Why do we do the plastic limit test?

Plastic limit test is one of the laboratory tests used internationally to differentiate or classify soils into groups. … The boundary of soil between the plastic and solid state means, the limit at which the soil starts to behave as a plastic.

Is code for liquid limit of soil?

STANDARD • IS: 2720 (Part 5) 1985. DEFINITION • Liquid Limit is defined as the water content at which the soil changes from liquid state to plastic state. APPARATUS • Casagrande apparatus confirming to IS: 9259-1979. Grooving tool.