oven drying method

Oven Drying Method of Soil : Lab Procedure, Observation & Calculations

 

The Oven Drying Method is used for determining the amount of water content in a specific soil.

It is necessary for understanding the bearing capacity as well as the probable settlement of the soil. It is carried out in the laboratory itself.

 


 

  1. Apparatus Required  

i. Thermostatically controlled oven maintained at a temperature of 110 ± 5oC

oven drying method

ii. Weighing balance, with an accuracy of 0.04% of the weight of the soil taken 

iii. Air-tight container made of non-corrodible material with a lid

iv. Tongs

 


 

  2. Quantity of Soil Required for Water Content Determination  

Size of particles more than 90% of passingMinimum Quantity ( grams)
425-micron sieve25
2 mm sieve50
4.25 mm sieve200
10 mm sieve300
20 mm sieve500
40 mm sieve1000

 


 

  3. Procedures in Oven Drying Method of Soil  

The procedure for the oven drying method can be listed as follows:

i. The air-tight container along with its lid must be first weighed(W1).

ii. The specimen sample is then taken in the container and the container along with its lid and the sample is weighed(W2).

iii. Then, the container is left in the oven. The specimen is dried to a constant weight at a temperature ranging from 105 degrees Celsius to 110 degrees Celsius for a period of about 16 to 24 hours.

iv. The container along with the lid and dried sample is finally weighed(W3).

v. The moisture content is then calculated using the following formula:

W= [ (W2-W3) / (W3-W1) ] * 100

Where,

W1= Weight of the container with a lid in grams

W2= Weight of the container with lid and wet sample in grams

W3= Weight of the container with lid and dry sample in grams

Note: To get an accurate value; a minimum of three soil samples should be taken to test and average water content should be taken as a result. 

 


 

  4. Observations and Calculations of Oven Dry Method  

Sl. No.Observations and CalculationsDetermination No.
123
Observation
1Container No.
2Weight of empty container (W1)
3Weight of container + soil (W2)
4Weight of container + dry soil (W3)
Calculations
5Weight of water Mw= M2 – M3
6Weight of solids, Ms= M3 – M1
7Water content= (5)/(6)x100

 


 

  5. Result of Oven Dry Method  

Water content of the given soil sample = ______%

 


 

  6. Precautions in Oven Drying Method  

a. Temperature of the oven should be maintained between (105°-110°)C.

b. Wait to cool for the dry soil in a container to remove from the oven ( or use tongs).

c. For accurate calibration, the thermostat should be kept on checking on a regular basis.

 

Read Also: Liquid Limit Test of Soil