Table of Contents
Cone Penetrometer Test is the second method of determining the liquid limit test of soil. This test utilizes a cone penetrometer for the test.
1. Apparatus Required
a. Sieve of 425-micron
c. Weighing balance with the accuracy of o.01 gm
d. Cone penetrometer
2. Sample Preparation for Cone Penetrometer Test
Soil passing through the 425-micron sieve is taken and dried in an oven at 60 deg. Celcius. Present molds in the soil sample are broken utilizing a wooden mallet.
3. Procedure of Cone Penetrometer Test
a. 150gm of prepared sample is taken.
b. Uniform paste of sample is made by adding distilled water.
c. The prepared paste is then transferred to the cylindrical cup of the cone penetrometer apparatus. Air should not be trapped in this process.
d. The paste is leveled up to the top of the cup and placed on the base of the cone penetrometer apparatus.
e. The cone penetrometer is adjusted in such a way that the cone point just touches the surface of the soil paste in the cup. Then, the initial reading is taken.
f. Release the vertical clamp allowing the cone to penetrate into soil paste under its own weight for 5 seconds. Note the nearest millimeter after 5 sec.
g. The test is repeated 4 times. Penetration should be in the range of 14 to 28 mm.
h. Determine the moisture content of each trial.
Plot a graph between water content on Y-axis and the cone penetration on X-axis.
The moisture content corresponding to cone penetration of 20 mm is the liquid limit value.
Liquid limit value(at 20 mm penetration) =
|Read Also: Plastic Limit Test|
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