WHAT IS THE GRADING LIMITS FOR FINE AGGREGATES?

To describe an aggregate by its maximum and minimum size is not sufficient. It has to be graded from its minimum to maximum size. IS-383 recommends the following grading limit for fine aggregates.

GRADING LIMITS FOR FINE AGGREGATES

Sieve Size	Percentage of Passing For
	Grading Zone-I	Grading Zone-II	Grading Zone-III	Grading Zone-IV
10 mm	100	100	100	100
4.75 mm	90 – 100	90 – 100	90 – 100	95 – 100
2.36 mm	60 – 95	75 – 100	85 – 100	95 – 100
1.18 mm	30 – 70	55 – 90	75 – 100	90 – 1000
600 micron	15 – 34	35 – 59	60 – 79	80 – 100
300 micron	5 – 20	8 – 30	12 – 40	15 – 50
150 micron	0 – 10	0 – 10	0 – 10	0 – 15

IMPORTANT NOTES

• Since the values for 600 micron size are not overlapping for different zones, it is used for confirming the zone of a sample of fine aggregate.
• Zone-I represents the coarse sand and zone-IV represents the finer sand in all the four zones.
• Fine aggregate belonging to zone-IV should not be used in RCC work unless tests have been made for suitability of mix proportion.