In india -Delhi
the sand available is Fine Jamuna. In the Sand mica particles are
Pl. tell,what will be the affect of mica particles on the
especially for plaster work. Can we measure the quanity of the mica
asked by Mr
Sanjay Kumar Deedwania)
being flaky & laminated affects strength & durability of mortar
/concrete in the same way as other such particles do. The effect
& strength is more for leaner mixes.
sands, mica content could be as
high as 12%. The problem is further aggravated if the sand is of
variety (Ganges sand could have
modulus as low as 0.6) .
variety of mica is more harmful than the mica biotite variety. Jamuna
mainly biotite with small percentage of muscovite particles; whereas Ganga sand is mainly muscovite with small
Indian Standards do not prescribe any test
for measuring the quantity of
mica. You can, however, measure the mica content by Floatation/Density
separation method or the Wind
blowing method; former being more accurate."