Particle Size Distribution (Gradation):

The particle size distribution is determined by passing the aggregates through a set of standard IS sieves (Figure) and determining the percentage passing the sieve.

Figure: Sieve Analysis of an Aggregate Sample

The result is expressed as in Table below.

Table: Typical Gradation of Aggregates

Generally, coarse aggregates are those that are retained substantially on 4.75 mm sieve, and fine aggregates are those passing substantially 4.75 mm sieve.