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. Standard test methods for liquid limit, plastic limit, and. The aline may be mathematically represented by equation 1. To determine the value of the liquid limit of a soil sample. Rapid determination of liquid limit of soils by flow index. The method described herein is based upon aashto designation t89 which has been modified for new york state department of transportation use. Determine liquid limit of soil specimen by casagrande method. Liquid limit ll or wl the water content, in percent, of a soil at the arbitrarily defined boundary between the semiliquid and plastic states. Pdf determining casagrande liquid limit values from cone. The casagrande plasticity chart is made by plotting the plasticity index versus the liquid limit.
After we have done the experiment liquid limit and plastic limit tests, we found that the plastic index of the soil is equal to 27 and the liquid limit of the soil is equal to 50. Liquid limit ll or is defined as the arbitrary limit of water content at which the soil is just about to pass from the plastic state into the liquid state. Liquid limit and plastic limit tests lab experiments. Determine the liquid limit of soil civil engineering. The value of liquid limit is used in classification of the soil and it gives an idea about plasticity of the soil. Plastic limit test, procedures, sample calculations. Liquid limit is defined as the minimum water content at which a pat of soil cut by a groove of standard dimension will flow together for a distance of 12 mm 12 inch under an impact of. The liquid limit determination for soils is one of the most important of these tests. Liquid limit, plastic limit, and plasticity index of soils abstract atterberg limits are a basic measure of the critical water contents of a finegrained soil, such as its shrinkage limit, plastic limit, and liquid limit. As the starting procedures of liquid limit test and plastic limit test are.
Place a piece of masking tape across the outside bottom of the cup parallel with the axis of the cup hanger pivot. Report the water content corresponding to 25 blows, read from the flow curve as the liquid limit. What is the significance of taking 25 blows in a liquid. A flow curve shall be plotted on a semilogarithmic graph representing water content on the arithmetical scale and the number of drops on the. 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. These limits are expressed as percent water content. The liquid and plastic limits of soils are often referred the as the atterberg limits. The plasticity chart figure 11 will provide you with a method for determining the type of fines.
Liquid limit is defined at which the water content the soil changes from the liquid state to the plastic state. Plastic limit, pl compute the average of the water contents obtained from the two plastic limit tests. The standard method for determining the liquid limit of soils 1 requires that at least three random trials be made. Used to test resiliency of hard rubber base of liquid limit machines. The onepoint liquid limit, method b, uses the data from two trials at one water content multiplied by a correction factor to determine the liquid limit. Pdf consistency limits are fundamental properties of fine grained soils. Atterberg limit test soil mechanics basic civil engineering. This is the limiting moisture content at which the cohesive soil passes from liquid state to plastic state. The atterberg limits are a basic measure of the critical water contents of a finegrained soil. Liquid limit ll or wl the water content, in percent, of a soil at the arbitrarily defined boundary between the semi liquid and plastic states. They are as follows, solid semi solid liquid plastic. Liquid limit, plastic limit, and plasticity index of soils abstract atterberg limits are a basic.
September 2014 note 2a convenient procedure for adjusting the height of drop is as follows. Liquid limit ll is defined as a limiting water content separating the viscous liquid state and plastic state of soil consistency. The limit is defined as the moisture content, in percent, required to close a distance of 0. Liquid limit is the water content at which soil changes from liquid to plastic state. Set the log base to 2 and set the minimum x value to 6. The atterberg limits which are most useful for engineering purposes are the liquid limit, plastic limit, and shrinkage limit. Determination of liquid limit and plastic limit of soil.
Liquid limit of soil, determination of liquid limit plastic limit, atterberg limit test, cone pentrometer method for more detail visit our website. Plastic limit test is one of the laboratory tests used internationally to differentiate or classify soils into groups. Liquid limit of soil, determination of liquid limit. Astm d 4318 standard test method for liquid limit, plastic limit, and. Features a spirit level for maintaining a level testing position. Atterberg limits reference data sheet reference data sheet 2 liquid limit test multipoint liquid limit method a perform the test from wet to dry. The amount of water in the soil determines the type of soil. For a more accurate calculation of the liquid limit n25, set the x axis to log scale. Rapid methods for determining liquid limits of soils. Liquid limit of soil mixtures article pdf available in geotechnical testing journal 83. Definition liquid limit is defined as the water content at which the soil changes from liquid state to plastic state. Definition liquid limit is defined as the water content at which the soil changes from liquid state to. The calculated liquid limit of the soil sample is 34, its plastic limit as 20, and. Liquid limit is the minimum amount of water required to be added to a soil, expressed as a percentage of the dry weight of the soil, that will just make it to flow like a liquid when.
Draw another line from this point left to the yaxis. Atterberg limits liquid limit testing liquid limit testing determines the water content at which soil changes from a liquid to a plastic state. Liquid limit test indian institute of technology kanpur. Commonly, two approaches, named casagrande apparatus and cone penetrometer methods are used to. Pdf determination of plastic and liquid limits using the reverse. Draw a straight line up from 25 on the xaxis until it reaches your plotted line. The liquid limit ll is one of the essential geotechnical parameter for finegrained soils. Liquid limit is defined as the water content at which the soil changes from liquid. Liquid limit 26 plastic limit 15 plasticity index 11 0 5 10 15 20 25 30 35 0 5 10 15 20 25 30 35 no. The water content at which soil sample change from plastic state to semisolid state. Determination of liquid limit and plastic limit of soil youtube. How to make liquid limit graph in excel spreadsheet hubpages. This lab is performed to determine the plastic and liquid limits of a fine grained soil.
At the liquid limit the clay is practically like a liquid,but possesses a small shearing. Atterbergs limits are liquid limit, plastic limit, and plasticity index. Ruwan rajapakse pe, ccm, cce, avs, in geotechnical engineering calculations and rules of thumb second edition, 2016. Atterberg limits reference data sheet reference data sheet. The plastic limit, pl, is the average of the two water. What is the plastic limit and liquid limit of soil. Determination of liquid limit and plastic limit of soil nctel. The liquid limit of a soil is the water content at which the soil behaves practically like a liquid, but has small shear strength. The edge of the tape away from the cup hanger should bisect the spot on the cup. There soil can be classified into four states depending on the water content of soil. Computational methods may be substituted for the graphical method for fitting a. As the graph suggest, the date acquired falls near the best fit line which means our data were quite consistent. This procedure determines the liquid limit of soils, defined as the water.
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