The Liquid Limit (LL) is the moisture content at which a fine-grained soil no longer flows like a liquid . • The Plastic Limit (PL) is the moisture content at which a fine-grained soil can no longer be remolded without cracking.
What is liquid limit of a soil?
Liquid limit is the water content where the soil starts to behave as a liquid . Liquid limit is measured by placing a clay sample in a standard cup and making a separation (groove) using a spatula. The cup is dropped till the separation vanishes. The water content of the soil is obtained from this sample.
What is plastic limit?
Plastic limit is defined as the water moisture content at which a thread of soil with 3.2mm diameter begins to crumble .
What is plasticity of soil?
Plasticity of soil is its ability to undergo deformation without cracking or fracturing . Engineering Properties:- The main engineering properties of soils are permeability, compressibility and shear strength.
What is liquid limit and plastic index?
The plasticity index (PI) is a measure of the plasticity of a soil. The plasticity index is the size of the range of water contents where the soil exhibits plastic properties. The PI is the difference between the liquid limit and the plastic limit (PI = LL-PL) .
Why is plastic limit important?
Importance of Plastic Limit Test of Soil
The value of the plastic limit is used to classify the fine-grained soils and evaluating the activities of clayey soil . 2. It indicates the toughness index of soil. ... It gives an idea regarding the consistency of soil.
What does a high plastic limit mean?
In general, the plasticity index depends only on the amount of clay present. 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 .
How do you find the plastic limit of soil?
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 liquid limit of soil Quora?
[1] Liquid Limit: It is defined as the moisture content at which a clayey soil loses its plasticity and changes its behaviour to liquid . [2] Plastic Limit: It is the moisture content at which a clayey soil attains plasticity. Hope this helps.
What is the use of liquid limit test?
The liquid limit is one of the measured parameters of the Atterberg limits test, which is used for differentiating consistency states of finer particles in soil material .
When the plastic limit of a soil is greater than the liquid limit then the plasticity index is?
Plasticity Index = Liquid Limit – Plastic Limit. This parameter cannot be negative if plastic limit, in some exceptions, is larger than the liquid limit, it is considered to be zero and soil is considered non-plastic.
What is cohesion and plasticity?
Cohesion sticking or binding of soil together . nd plasticity helps the soil to attain any shapes that we require. if the cohesive property and plasticity increases it is easy to make any shapes with the soil. Plasticity is a soil property which enables a moist soil to change shape.
What is liquid state of soil?
Liquid Limit (LL) is the water content at which soil changes from a plastic to a liquid state when the soil specimen is just fluid enough for a groove to close when jarred in a specified manner. Plastic Limit (PL) is the water content at the change from a plastic to a semi-solid state.
What is liquid limit formula?
Use the number of drops along with the water content of the samples to calculate the liquid limit. ... Subtract the weight of a dry soil sample from the weight of a wet soil sample and multiply by 100 . Divide the result by the weight of the wet sample to get the percent water content for that sample.
Is code liquid limit?
of Liquid Limit -.
The moisture content corresponding to cone penetration of 20 mm shall be taken as the liquid limit of the soil and shall be expressed to the nearest first decimal place.
Why is plastic limit and liquid limits important?
The plastic limit of soil increases if organic matter is added , without any significant increase in the liquid limit. Therefore soils with high organic content have a low plasticity index. The liquid limit of a soil is an indicator of the compressibility of a soil.
What does low plastic limit mean?
The Plastic Limit, also known as the lower plastic limit, is the water content at which a soil changes from the plastic state to a semisolid state . OR. The soil moisture content at which any increase in the moisture content will cause a semi-solid soil to become plastic.
Can the liquid limit of a soil be greater than 100?
The consistency of fine-grained soil for different moisture content is described by Atterberg’s limits. Liquid limit, plastic limit, shrinkage limit etc are some of the Atterberg’s limits. ... Therefore, the Atterberg’s limits can be greater than 100 .
What is plastic limit PL plastic limit is?
Plastic limit (PL) is the moisture content at which a fine-grained soil cannot be remolded without cracking . ... The PL is expressed as a percentage of the weight of the oven-dry soil, at the boundary of plastic and semi-solid consistency.
What is shrinkage limit?
Shrinkage limit (SL) is the moisture content at which a fine-grained soil does not change the volume on drying ; the moisture loss is compensated by air that enters its pores. It can be determined in a laboratory using a disturbed or undisturbed soil sample.
When the plastic limit of a soil is zero the soil is?
sand .
What is ratio of a soil mass can?
Void ratio (e) is the ratio of the volume of voids to the volume of solid of the soil considered. Since the volume of voids can be less than the volume of solids or it can be greater than the volume of solids. Hence, it can take any value greater than zero.
What is the degree of saturation at shrinkage limit?
At a water content of less than SL′, there is a negligible change in the void ratio due to a further reduction in the water content. If the initial degree of saturation during normal shrinkage is 100% , SL′ equals SL. Fig. 4 describes how the initial degree of saturation affects the shrinkage limit.
What is water retention capacity?
Water Holding Capacity is the ability of a certain soil texture to physically hold water against the force of gravity . It does this by soil particles holding water molecules by the force of cohesion.
What is type AB and C soil?
Type B soil has medium unconfined compressive strength ; between 0.5 and 1.5 tons per square foot. ... Type C soil is the least stable type of soil. Type C includes granular soils in which particles don’t stick together and cohesive soils with a low unconfined compressive strength; 0.5 tons per square foot or less.
What is cohesion and adhesion of soil?
Cohesion causes water molecules to stick to one another and form water droplets . Adhesion Force: This force is responsible for the attraction between water and solid surfaces. For example, a drop of water can stick to a glass surface as the result of adhesion.
