Fineness Modulus Fineness Modulus dr. rifat (Civil/Environmental) (OP) 22 Mar 17 18:14 Dear Engineer, Why fine aggregates minimum fineness modulus is 0 or 2 and maximum is 5?? RIFAT RE: Fineness Modulus JMackNH (Civil/Environmental) 23 Mar 17 16:59 Fineness modulus, at least in relation to concrete, affects the amount of water used in batching and the workability of the mix. A low FM (fine sand) typically is easier to finish, but requires more cement and water to account for increased particle surface area. A high FM mix (coarse sand) will increase the likelihood of bleeding and decrease the workability. FM for concrete sand, at least here in the Northeast, has to be between 2.3 and 3.1.