What is entrained water?

Entrapped water is water that is held within the pores or spaces of a material or substance, such as soil or rock. It is held in place by capillary forces and can be removed by mechanical means, such as centrifugation, or by thermal means, such as drying or heating. Entrapped water is often found in fine-grained materials, such as clays, silts, and organic matter. It can also be found in larger-grained materials, such as sand and gravel, if the pores or spaces between the particles are small enough to hold water.

The composition and properties of entrained water can vary depending on the source of the water and the material in which it is entrapped. It may contain dissolved ions and minerals, and it may be contaminated with organic matter or pollutants. The amount of entrained water present in a material can affect its physical properties, such as its strength, density, and thermal conductivity.

Entrapped water is important in a variety of environmental and engineering applications. For example, the amount of entrained water in soil can affect its ability to store and transmit water, as well as its susceptibility to erosion. The presence of entrapped water in rock can affect its strength, durability, and resistance to weathering. In engineering applications, entrapped water can affect the performance of materials used in construction, such as concrete and asphalt, as well as the design of structures and systems that involve the movement or control of water.