PACKAGE : I Bid Document VOLUME : II - Public Health Engineering

) Gradation:
(I) Unless otherwise directed or approved by the Engineer, the grading of
sand shall be within the limits indicated under here:
IS Sieve
Percentage passing for
Grading Grading Grading Grading
Designation Zone – I Zone – II Zone – III Zone AVE
10mm 100 100 100 100
4.75mm 90 – 100 90 – 100 90 – 100 95– 100
2.36mm 60 – 95 75 – 100 85 – 100 95 – 100
1.18mm 30 – 70 55 – 90 75 – 100 90 – 100
600micron 15 – 34 35 – 59 60 – 79 80 – 100
300micron 5 – 20 8 – 30 12 – 40 15 – 50
150micron 0 – 10 0 – 10 0 – 10 0 - 15
(II) Where the grading falls outside the limits of any particular grading zone of
sieves, other than 600 micron I.S. sieve, by total amount not exceeding
5 percent, it shall be regarded as falling within that grading zone. This
tolerance shall not be applied to percentage passing the 600 micron I.S.
sieve or to percentage passing any other sieve size on the coarser limit of
Grading Zone I or the finer limit of Grading Zone AVE. Fine aggregates
conforming to Grading Zone AVE shall be used. Mix designs and
preliminary tests shall show its suitability for producing concrete of
specified strength and workability.
c) Fineness modulus:
The sand shall have a fineness modulus of not less than 2.2 or more than 4.2. The
fineness modulus is determined by adding the cumulative percentages retained on
the following I.S. sieve sizes (4.75mm, 2.36mm, 1.18mm, 600micron, 300micron
and 150micron) and dividing the sum by 100.
GTS : General Technical Specification. Page 51