particular specifications (road works) - CIDCO Maharashtra Ltd.

CIDCO OF MAHARASHTRA LTD
C.A.No.01/CIDCO/SE(KHR)/EE(KHR-I)/2010–11 Pg. No. 492
iv) The specific gravity of sand shall not be less than 2.6.
v) In no case shall fine aggregate be accepted, containing more than
2% by dry weight not more than 3½% by dry volume, not more
than 5% by dry volume of clay, loam or silt. If any sample of fine
aggregate shown more than 5% of clay, loam, silt in one hour’s
settlement after shaking in excess of water, the lot represented by
the sample shall be rejected.
vi) The following two field tests are recommended for ascertaining the
percentage of clay lumps and impervious organic material and the
contractors shall carry out the same if the Engineer deems
necessary.
1. Test for determining silt in sand
Fill a calibrated tumbler with sand to half its volume and
water there to until the tumbler is three quarters full. Shake up
the mixture vigorously and allow it to settle for about an hour.
The volume of silt visible on top of the sand shall be measure.
If the volume of the silt standing over the sand exceeds 5% of
total volume of sand. The same shall be rejected.
2. Colorometric test for organic impurities
The sample of sand shall be mixed with equal volume of 3%
solution (about one ounce, in a quarter of water) of caustic
soda/sodium hydrauxide taken in a plain glass and the
mixture shall be allowed to stand for 24 hours. The liquid
standing above the sand shall not be darker than lights straw
(pale yellow) colour. If the colour is marked yellow or brown,
the test would indicate presence of organic material in
excessive amount.