Grading of Aggregates and Grading Limits

Grading of aggregates are determination of particle size distribution of aggregates. Grading of aggregates is an important factor for concrete mix design. These affect the concrete strength as well as durability.

Proper grading is important for concrete construction. Following tables provides details for grading limits of aggregates.

 Grading Limit for Single Sized CoarseAggregates

(Based on Clause 4.1 and 4.2 of IS: 383- 1970)

IS Sieve	Percentage passing for single sized aggregates of nominal size(mm)
	63 mm	40 mm	20 mm	16 mm	12.5 mm	10 mm
80 mm	100	–	–	–	–	–
63 mm	85 – 100	100	–	–	–	–
40 mm	0 – 30	85 – 100	100	–	–	–
20 mm	0 – 5	0 – 20	85 – 100	100	–	–
16 mm	–	–	–	85 – 100	100	–
12.5 mm	–	–	–	–	85 – 100	100
10 mm	0 – 5	0 – 5	0 – 20	0 – 30	0 – 45	85 – 100
4.75 mm	–	–	0 – 5	0 – 5	0 – 10	0 – 20
2.36 mm	–	–	–	–	–	0 – 5

Grading Limits for Fine Aggregates

(Based on Clause 4.3 of IS: 383 – 1970)

IS Sieve Designation	Percentage Passing
	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 – 100
600 microns	15 – 34	35 – 59	60 – 79	80 – 100
300 microns	5 – 20	8 – 30	12 – 40	15 – 50
150 microns	0 – 10	0 – 10	0 – 10	0 – 15