Materials

Fineness Modulus

An index of how coarse a fine aggregate is: the sum of cumulative percentages retained on standard sieves, divided by 100.

The fineness modulus is found from a sieve analysis by adding the cumulative percentages retained on the standard sieve series and dividing by 100. A larger number means a coarser sand. Sand for concrete typically falls between about 2.3 and 3.1.

It is used in mix design to choose how much coarse aggregate a mix can carry: a finer sand needs more paste to coat it and allows more coarse aggregate per unit volume of concrete for the same workability.

How much of the FE Civil exam is Materials?