Civil and Building Engineering.

A soil sample is known to be saturated when it is weighed in the laboratory and its total weight is W. The sample is then placed in an oven at a temperature of 110 C and dried completely. The dry weight is measured as Wd. The loss in weight of the soil sample is the weight of water (Ww W Wd) that was in the original sample of soil. From this test, it is possible to compute the water content using

where water content is expressed as a percentage. Water contents are determined for almost every sample tested in a soils laboratory because soil properties are found to be sensitive to changes in water content.
The void ratio is defined as the volume of voids in a soil divided by the volume of the solid materials in a soil. The void ratio is convenient to use when calculating unit weights and strains due to consolidation. The symbol
used for void ratio is e and is computed as