The moisture content test is to determine the amount of water present in soil expressed as a percentage of the mass of dry soil. The moisture content of a soil is assumed to be the amount of water within the pore space between the soil grains which is removable by oven-drying at a temperature not exceeding 110°C. The moisture content has a profound effect on soil behaviour.
The oven-drying method is regarded as standard laboratory practice.
• a drying oven with temperature of 105°C to 110°C
• a balance readable to 0.1 g
• a metal container
- Clean and dry the container, then weigh it to the nearest 0.1 g (m1)
- A representative sample shall be crumbled and loosely placed in the container.
- For fine-grained soils, the sample weight shall be min. 30 g.
- For medium-grained soils, the sample weight shall be min. 300 g.
- For coarse-grained soils, the sample weight shall be min. 3 kg.
- The container with the sample shall immediately be weighed (m2) and placed in the oven to dry at 105°C for a minimum of 12 hours.
- After drying, weigh the container and the contents (m3)
Calculate the Moisture Content of the soil specimen, w, as a percentage of the dry soil mass to the nearest 0.1%, from the equation:
m1 is the mass of the container (in g)
m2 is the mass of the container and wet soil (in g)
m3 is the mass of the container and dry soil (in g)
The United Republic of Tanzania ministry of works, Laboratory Testing Manual 2000, Novum Grafisk AS, Skjetten Norway