MOISTURE CONTENT OF SOIL
STANDARD FOLLOWED :
As Per IS: 2720 (Part 2) – 1973 (Reaffirmed 2015)
OBJECT :
To Determine the Natural Moisture Content of Soil.
THEORY :
The ratio of the weight of water present to the weight of dry soil in a given soil mass. It is usually expressed as percentage of the dry mass.
APPARATUS :
1.Metal container with lid (air tight non-corrodible)
2.Drying oven
3.Desiccator
4.Balance (of sufficient sensitivity to weigh the soil samples to an accuracy of 0.04 percent of the weight of the soil taken for the test)
5. Tong (one pair)
PROCEDURE :
•Clean, dry the metal container and weigh with lid. Take about 25 g of soil specimen of fine grained soil, or 200 g specimen for medium grained soil.
•Place the soil specimen loosely in the container and weigh with lid. Remove the lid of the container and place it in the oven. Maintain the oven temperature at 105 - 110°C. Completely dry the soil specimen in the oven till its mass is constant.
•The drying period of the soil specimen is 24 hours.
•After drying, take the container out of the oven, keep the lid on it and place it in desiccator for cooling. Weigh the container with dry soil and lid.
Note :-
Oven drying at 110 ± 50c does not result in reliable water content values for soil containing gypsum or other minerals having loosely bound water of hydration or for soil containing significant amounts of organic material. Reliable water content values for these soil can be obtained by drying in an oven at approximately 60 to 800c.
PRECAUTIONS & MAINTENANCE:
The wet soil specimen should be kept loosely in the metal container Care should be taken to avoid over heating of the soil.