Objective:

To determine the particle size distribution of coarse aggregates by sieving and finding the fineness modulus.

Apparatus used:

Mechanical shaker, Trays, Set of fine sieves with pan, Weighing scale etc.

 DescriptionFineness Modulus of Coarse Aggregate is a measure of size of particles of coarse aggregate. It is an imperial factor obtained by adding the cumulative percentages of coarse aggregate retained on each of the standard sieves and dividing the sum by an arbitrary number 100.

STEP  1 

 Take coarse aggregate in a pan and measure it to 1Kg using the weighing scale.

0.000 g

1000.00 g

STEP    2 

 Arrange the sieves in the decreasing order of their size and place the pan at the bottom and then add weighed quantity of fine aggregate to the top most sieve and close the lid.

STEP   3 

 Place the set of sieves in the mechanical shaker and allow to shake for 10 minutes.

STEP   4 

 Collect the soil fraction retained on each sieve in a separate container and weigh it.

0.000 g

STEP    6 

Observations:

Coarse Aggregate(Weight of coarse aggregate taken=3000g)

Sieve size(mm)	Weight retained(g)	Percentge weight retainedWeight retained x 100⁄Weight of coarse aggregate taken	Cumulative percentage weight retained (Cumulative % weight retained of sieven + % weight retained of sieven-1)	Cumulative percentage finer 100 - Cumulative % weight retained of sieven	Fineness modulusSum of cumulative % weight retained⁄100
80	0
40	0
20	2622.5
16	349.25
10	28.25
4.75	0
2.36	0
1.18	0
0.6	0
0.3	0
0.15	0
Pan	0
	3000

*Hover on the table headings to know the formula

Inference: