OBJECTIVE
Determine the natural content of the given soil sample.
NEED AND SCOPE OF THE EXPERIMENT
In almost all soil tests natural moisture content of the soil is to be determined. The knowledge of the natural moisture content is essential in all studies of soil mechanics. To sight a few, natural moisture content is used in determining the bearing capacity and settlement. The natural moisture content will give an idea of the state of soil in the field.
DEFINITION
The natural water content also called the natural moisture content is the ratio of the weight of water to the weight of the solids in a given mass of soil. This ratio is usually expressed as percentage.
APPARATUS REQUIRED
- Non-corrodible air-tight container.
- Electric oven, maintain the temperature between 1050 C to 1100 C.
- Desiccator
- Balance of sufficient sensitivity.
PROCEDURE
Clean the container with lid, dry it and weigh it (W1).
Take a specimen of the sample in the container and weigh with lid (W2). 3. Keep the container in the oven with lid removed. Dry the specimen to constant weight maintaining the temperature between 1050 C to 1100 C for a period varying with the type of soil but usually 16 to 24 hours.
4. Record the final constant weight (W3) of the container with dried soil sample. Peat and other organic soils are to be dried at lower temperature (say 600 ) possibly for a longer period.
Certain soils contain gypsum which on heating loses its water if crystallization. If itb is suspected that gypsum is present in the soil sample used for moisture content determination it shall be dried at not more than 800 C and possibly for a longer time.
OBSERVATIONS AND RECORDING
Data and observation sheet for water content determination
