FREE SWELL INDEX TEST OF SOILS

1. DETERMINATION OF FREE SWELL
INDEX OF SOILS
PRESENTED BY- DAVINDERPAL SINGH
ASSISTED BY- AKHILESH KAUSHAL

2. ABOUT TEST
 IT IS A TEST OF SOIL AND COMES UNDER
SOIL MECHANICS TESTS. (GEOTECHNICAL
ENGINEERING)
 CODE USED IS:2720 (PART 40)-1977

3. APPARATUS
 IS SIEVE 425 micron (IS:460)
 100 ml CAPACITY FLASK (IS:878) TWO ARE
REQUIRED
 STIRRER (THIN ROD, CAN BE GLASS ROD)
 OVEN
 ENAMEL TRAY
 WEIGHING BALANCE (accurate upto 0.01 g)

4. PROCEDURE
 Soil sample upto 500 gram is taken from desired site and kept
in oven for 24 hours at (100-110)0C, so that sample becomes
oven dried.
 Then sample is sieved through 425 micron IS SIEVE and
sample passed is taken.
 Sample finer than 425 micron is taken in two flask of 100 ml
capacity, 10 gram in quantity in each flask.

8. PROCEDURE
 In first flask already filled with 10 gram oven dried sample
finer than 425 micron, kerosene oil is added upto 100 ml
mark.
 In second flask which is also filled with 10 gram oven-dried
sample finer than 425 micron, distilled water is added upto
100 ml mark of flask.
 Then sample are stirred well by a stirrer to remove entrapped
air in it.

10. PROCEDURE
 Then two flasks are kept ideal for not less than 24 hours
time allowing sample to swell and settle.
 Atleast Three Readings are taken and their average is
given as a result.

12. FORMULA

13. RESULT
 FREE SWELL INDEX=((VW – VK) / (VK))*100 = ((9 -8) / (8))*100 =
12.5%
 TAKE FURTHER TWO READINGS AND TAKE THEIR
AVERAGE.