A sieve analysis (or gradation test) is a practice or procedure used (commonly used in civil engineering) to assess the particle size distribution (also called gradation) of a granular material.
The size distribution is often of critical importance to the way the material performs in use. A sieve analysis can be performed on any type of non-organic or organic granular materials including sands, crushed rock, clays, granite, feldspars, coal, soil, a wide range of manufactured powders, grain and seeds, down to a minimum size depending on the exact method. Being such a simple technique of particle sizing, it is probably the most common.[1] Contents * 1 Procedure * 1.1 Preparation * 2 Results * 3 Methods * 3.1 Throw-action sieving * 3.2 Horizontal sieving * 3.3 Tapping sieving * 3.4 Sonic sieving * 3.5 Wet sieving * 3.6 Air Jet Sieving * 4 Types of gradation * 5 Limitations of sieve analysis * 6 Properties * 7 Engineering applications * 8 Forecast * 8.1 "Sieving" with digital image processing * 9 See also * 10 References * 11 External links |
Procedure
Sieves used for gradation test.
A mechanical shaker used for sieve analysis.
A gradation test is performed on a sample of aggregate in a laboratory. A typical sieve analysis involves a nested column of sieves with wire mesh cloth (screen). See the separate Mesh (scale) page for details of sieve sizing.
A representative weighed sample is poured into the top sieve which has the largest screen openings. Each lower sieve in the column has smaller openings than the one above. At the base is a round pan, called the receiver.
The column is typically placed in a mechanical shaker. The shaker shakes the column, usually for some fixed amount of time. After the shaking is complete the material on each sieve is weighed. The weight of the sample of each sieve is then divided by the total weight to give a percentage retained on