Short Notes on Fineness modulus

 Fineness modulus:- 

Fineness modulus of an aggregate in an index number which gives an average size of particle in the aggregate. Fineness modulus is roughly proportional to the average size of particle in the aggregate. Coarser the aggregate higher the fineness modulus and vice versa. It is determined by adding the cumulative percentage of material coarser than each of the following test sieves and dividing the sum by 100. Test sieves 3.35 mm, 2.36mm,1.8 mm,600 micron,300 micron,150 micron and 75 micron