Siiviläjakautuma

Siiviläjakautuma, also known as sieve analysis or granulometry, is a laboratory method used to determine the particle size distribution of a granular material. This technique is widely employed in various fields, including civil engineering, geology, agriculture, and manufacturing, to characterize materials such as soil, sand, gravel, cement, and even food products.

The process involves using a series of sieves with progressively smaller mesh sizes. A weighed sample of the material is placed on the top sieve, and the stack is shaken vigorously for a specific duration. The shaking action causes smaller particles to fall through the mesh openings, while larger particles are retained on the sieve. After shaking, the material retained on each sieve is weighed separately.

The results of a sieve analysis are typically presented as a particle size distribution curve, which plots the cumulative percentage of material finer than a given particle size against the particle size itself. This curve provides a visual representation of the material's gradation, indicating whether it is well-graded (containing a wide range of particle sizes) or poorly-graded (containing a narrow range of particle sizes). Key parameters derived from the sieve analysis include the effective size, uniformity coefficient, and coefficient of curvature, which are used to assess the material's suitability for specific applications. For example, in civil engineering, the particle size distribution of aggregates significantly influences the strength, permeability, and workability of concrete and asphalt mixtures.