For full course visit our website : https://www.machenlink.com/course/soil-mehcanics/ Methods of determining water content 1. Oven drying Method 2. Sand Bath Method 3. Alcohol Method https://www.youtube.com/watch?v=KgrKaUgohHw&index=4&list=PLjNHcF09jOW0y3RNIZyvha_IDmIxpCDVB 4. Pycnometer Method https://www.youtube.com/watch?v=BCyfa8vawmw&list=PLjNHcF09jOW0y3RNIZyvha_IDmIxpCDVB&index=5 5. Calcium Carbide Method 6. Radiation Method 7. Torsional Balance Method For full course visit our website : https://www.machenlink.com/course/soil-mehcanics/

1. SOIL
MECHANICS
Determination of
Water Content

2. For full course visit our website,…
This is the excerpt from
Lecture 04
of
Soil Mechanics
www.machenlink.com

3. 5. Calcium Carbide Method
L. 04 Determination of Water Content
Procedure :
• One of the quickest method 5-7 minutes.
• Also known as rapid moisture method.
 4-6 gm of moist sample is placed in moisture meter
CaC2 + H2O = C2H2 + Ca(OH)2
𝐶𝐶2 𝐻𝐻2
Moist Sample
+
Ca𝐶𝐶2
Moisture meter
Dial gauge
added with calcium carbide (Ca𝑪𝑪𝟐𝟐)
that exert the pressure over the calibrated gauge given
moisture content of soil in terms of total weight of soil (w).
which react with water present in sample resulting in the
formation of acetylene gas (𝑪𝑪𝟐𝟐 𝑯𝑯𝟐𝟐)

4. 6. Radiation Method
L. 04 Determination of Water Content
• In this method two steel casing are lowered in the ground where the moisture content is to be determined.
• One of the casing consist of radio active material ( C-60 ) and other consist of detector.
• When radioactive material is activated it emits neutron
• These neutron strike with hydrogen atom present in the water molecule resulting in loss in energy of the
neutron, that is being detected by detector and is further calibrated to give the water content of soil.
Radioactive material
Detector
Steel casing
𝐻𝐻2OC60
Neutron

5. 7. Torsional Method
L. 04 Determination of Water Content
Procedure :
• In this method infrared radiation are use for drying of the moist sample.
• In this method weighing and drying is being carried out simultaneously hence is used for soil
that quickly reabsorb the moisture from atmosphere.
Infrared radiation
250W
220-230V
50 Hz
Moist
soil
sample