UCE – THIRUKKUVALAI
DETERMINATION OF SPECIFIC GRAVITY OF SOIL SOLIDS
To determine the specific gravity of given soil solids.
4.75 mm IS sieve
(a). IS Sieve
Dry the pycnometer and weigh it with its cap. (W1)
Take about 200gmof oven dried soil passing through 4.75mm sieve into the pycnometer and
weigh again (W2).
Add sufficient de-aired water to cover the soil and screw on the cap.
Shake the pycnometer well and remove entrapped air if any.
After the air has been removed, fill the pycnometer with water completely.
Thoroughly dry the pycnometer from out side and weigh it (W3).
Clean the pycnometer by washing thoroughly.
Fill the cleaned pycnometer completely with water up to its top with cap screw on.
Weigh the pycnometer after drying it on the outside thoroughly (W4).
Repeat the procedure for three samples and obtain the average value of specific gravity.
The specific gravity of given soil sample (G) = (
(𝑊2 −𝑊1 )
𝑊4 −𝑊1 )−(𝑊3 −𝑊2 )