|Wed Feb 24, 2016||Post #1|
|S L Gupta (Civil Engg)|
Join date: Mar 2008
For coarse sand see below
Fine aggregate/ coarse sand consists of natural sand, crushed stone
sand or crushed gravel stone dust. It should be hard, durable
chemically inert, clean and free from organic matter, not containing any
appreciable amount of clay balls or pellets and other harmful
impurities i. e. alkaline, salt, mica, decayed vegetation, lumps etc.
It should be passed through I. S. Sieve 4.75 MM. It should have the
finest modulus 2.50 to 3.50 and silt contents should not be more than
4%. Coarse sand should be either river sand or pit sand; or combination
of the two. It should be obtained from Badarpur Sand or Stone dust
obtained by crushing hard stones or gravel. It should also be obtained
from river bed such as Tajewala , Dadupur sand.
In general the sand particle should be coarser and have minimum silt contents. The silt contents should not be more than 4%.
The quality of the sand has more impact on the strength of the structure inspite of the quantity of the cement used.
1) If there is more silt in coarse sand, the strength of cement mortar is reduced from 1 % to 30%.
2) If you take best quality coarse sand, it will give maximum strength.
Quality of Coarse Sand
specification for the quality of coarse sand can be obtained by
laboratory test but in general we can judge the quality of coarse sand
in the field through the following ways.
1. Observe whether
there are any lumps of earth or clay balls, grass and decayed vegetation
etc. in coarse sand to check silt contents.
2. Take some samples of coarse sand in hand and observe
The particles of sand should be coarser.
Silt contents should be less
3. Take some sand in hand and drop it down
can simply check the quality of sand by taking some sand in the hand
and then dropping it down. If some finest material sticks with hand,
the sand has some silt contents and finer sand.
4. Check silts contents with the help of water
empty glass and put some sand and water in the glass and stir it well.
After some time the silt layer will be framed between sand and water
which shows the quantity of the silt contents present in the sand.
|Thu Feb 25, 2016||Post #2|
|K M Sendhil|
Join date: Apr 2015
|Sat Mar 05, 2016||Post #3|
Join date: May 2014
Ground work-Construction Questions (39)