written 5.3 years ago by |
The given sand sample has a fineness modulus 1.95, which is less than prescribed limit i.e.2.2-3.2. It indicates that sand particles are finer, which is not suitable for satisfactory concreting work.
Procedure to bring FM in prescribed limits:
i. The cumulative % retained of tested sand sample should be increased by adding sand particles which are having lesser % retained in the calculation.
ii. When quantity of such sand particles are increased, then FM of sand will be in the above mentioned range, which is also considered as well graded sand sample.
Importance of FM:
i. Fineness modulus of sand should be 2.2 to 2.6 for fine sand, which is helpful for minimizing voids ratio and increasing density of concrete mass.
ii. Well graded sand is also useful for good bonding of particles and related strength criteria of concrete.