Pakkausaste

Pakkausaste is a Finnish term used to describe the degree to which particles in a material are packed together. It refers to the density of packing within a given volume and is related to, or sometimes used interchangeably with, concepts such as packing density, porosity, and compaction. In practice, pakkautumisaste is a measure of how much of the total volume is occupied by solid particles versus voids.

In geotechnical engineering and soil science, pakkausaste often relates to the compaction state of a soil. It influences properties such as shear strength, stiffness, permeability, and settlement behavior. The degree of packing can be described qualitatively (loose, medium, dense) or quantitatively as a relative density or as a percentage of maximum achievable density in a given soil type or compaction test.

In powder technology and materials processing, pakkausaste describes how densely powders are compacted before forming, sintering, or other processing steps. A higher pakkausaste generally leads to higher green density and different final material properties, while excessive packing can affect flowability and defect formation.

Measuring methods vary by context but commonly include density determinations (based on mass and volume), oven-dry methods for moisture correction, and specialized tests for compaction and porosity. The concept is central to designing processes and structures where the interplay between solid packing, void space, and fluid flow determines performance and stability.

See also: porosity, density, compaction, relative density, packing fraction.