HOW TO CHECK WATER CONTENT OF SOIL BY OVER DRYING METHOD?

WATER CONTENT TEST BY OVER DRYING METHOD

Aim :- To determine the water content present in soil by oven drying method as per IS 2720.

Principle :- The water content (W) of a soil sample is equal to the mass of water divided by the mass of solid.

Apparatus :- 

• Thermostatically controlled electric oven maintained at a temperature of 110 C.
• Weighing balance, with an accuracy of 0.04% of the weight of the soil taken.
• Air-tight container made of non-corrodile material with lid.
• Tongs

Sample :-  The soil specimen should be representative of the soil mass. The quantity of the specimen taken would depend upon the gradation and the maximum size of particles as under.

Size of particles more than              Maximum quantity of 

90 % passing through                     the soil specimen to be

Is sieve                                            taken for test

425 micron                                       25 gm

2.0 mm                                             50 gm

4.75 mm                                           200 gm

9.5 mm                                             300 gm

19 mm                                              500 gm

37.5 mm                                           1000 gm

Procedure :-

1. Clean the container, dry it and weigh it with the lid. Note down the weight as W1. 

2. Take the required quantity of the wet soil specimen in the container and weigh it with the lid. Note down the weight as W2.

3. Place the container with its lid removed in theoven till its weight becomes constant. Normally for 24 hours.

4. When the soil has dried, remove the container from the oven using tongs.

5. Find the weight W3 of the container with the lid and dry soil sample.

Reporting of results :-

The water content W = W2 - W3   x 100 %

                                    W3 - W1

          

An average of three determination should be taken as water content of soil.