Theory

Liquid limit (wd) in the water content corresponding to the arbitory limit between liquid and plastic state of consistency of the soil. It is defined as the minimum water content at which the soil in the liquid state but a small shearing strength against flowing.


Apparatus

1.      Mechanical liquid device
2.    Grooving tools
3.    Porcelain evaporating dish about 12cm dia.
4.    Spatula flexible blade 8cm long and 2cm wide
5.     Balance
6.    Airtight container


Procedure

1.  Take 120gm of soil and mix it thoroughly with 20ml of distilled water and more a paste.

2.    Put a paste in a cup above the spot where it rest on the base plate and spread it.

3.  Divide a sample in the cup by grooving tool along the diameter through centre line of cone.

4.    Now lift and drop the cup by turning crank and weight to revolution per sec.

5.  Until the haw’s same in contract with the bottom of the groove along a distance at about 10cm.

6.    Record the no. of blows required to close the groove of approximate length of 10mm.

7.     Determine the moisture content of the sample as already explained.

8.    Repeat the test with the charge water content.


Precaution

1. Highly plastic glazed should be left 24hrs after mixing water so as to unable uniform distribution with in the soil mass because the permeability of clay is very low.

2. Distilled water should be used for making paste as the liquid limit changes with the soil concentration.

3.  The cup should fall freely and should not have to much side lay in the hinge.



 Diagram






Observation


OBS. NO.
DETERMINATION NO.
A1
A2
A3
A4
A5
A6
01
No. of blows
34
23
18
12


02
Mass of container + wet soil (M2)
38.86
46.63
60.36
45.43


03
Mass of container + dry soil (M3)
34.91
39.59
49.02
37.22


04
Mass of water
3.95
7.04
11.34
6.21


05
Mass of container (M1)
26.08
25.30
26.95
66.06


06
Mass of oven dried
8.83
14.29
22.07
11.16


07
Soil water contained
44.6
49.4
51.4
55.6




Calculation


Water content D = M2 – M3 / M3 – M1

1)     (38.86 – 34.91 / 34.91 – 26.08) X 100

= 44.6 %

2)   (46.63 – 39.59 / 39.59 – 25.30) X 100
= 49.26 %

3)   (60.36 – 49.02 / 49.02 – 26.95) X 100

= 51.38 %

4)   (43.43 – 37.22 / 37.22 – 66.06) X 100

= 55.6 %


Conclusion

The increase in the value of liquid indicates the increase in shear strength of the soil the value of the liquid indicates the soil properties such as shear strength permeability and permeability hence in this method determine.


Result

The liquid limit of given soil sample was found to be 49 % and the flow index of the sample found to be 25.5 %