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 %
