# AnsweredIS 383 - 2016 : Table 7 Coarse aggregates

#### VIDHYA SAGAR

##### Senior Member
Please explain the difference between Single sized aggregate of Nominal size & Graded aggregate of nominal size.

Thanks.
Vidhyasagar.

#### Dnyan Deshmukh

Staff member
Table no 7 in IS 383 contains, Surface characteristics of aggregates.

Table no 02 shows the passing % for graded as well as single size aggregates

what is single size aggregates - most of the aggregates are of that size, say 20mm aggregates will have 85 to 100% passing through 20 mm sieve and retaining on 16mm sieve. and hardly any aggregates goes below it.

Graded aggregates - this aggregates have all size particles in it, in graded 20mm aggregates you will get 20 mm, 10mm and 4.75 mm etc.

So graded aggregates may even have crush sand in it.

The acceptance limits for each type of aggregates are given in Table no 02.

Mostly in concrete, we use single size aggregates and then blend in proportion as per limits given in all in aggregate table for maximum size of aggregates.

Example: for max size of 20mm aggregates, all in aggregate grading have following limits.

20mm - 90 to 100%
4.75 - 30 to 50%
600 micron - 10 to 35%
150 micron - 0 to 6%

While doing mix designing, gradation report of 20mm, 10mm and crush sand / river sand (or its combination) are referred.

Then combine gradation of all sizes is calculated and adjusted to fit in the above limit by doing combination of different %

Say i took 20mm 30%, 10mm 20% and sand 50% so the combine gradation comes within limit of all in aggregate gradation.

When you use graded aggregates the process remains same but your coarse aggregates quantity may get increased.

In general all crusher plant do produce single size aggregates, natural rocks are taken as graded aggregates when they meets the passing requirement.

when i mix 20mm, 10mm and sand all together and supply it to you, it may be termed as graded aggregates and can be accepted as per the passing criteria.

#### SAURAV26

##### Newbie
Okay, I will explain to you in detail later. I will give you vivid details.

VIDHYA SAGAR

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