WHAT IS THE GRADING LIMITS FOR FINE AGGREGATES?

Grading Limit For Zone-1

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.
6 Comments

Add a Comment

Your email address will not be published. Required fields are marked *