Ar. Ravindra Patnayaka
B.Arch, M.Tech (Planning)
Assistant Professor in Architecture
Sand is a naturally
occurring granular material composed of finely
divided rock and mineral particles.
the most common constituent of sand is silica (silicon
dioxide, or SiO2), usually in the form of quartz.
SOURCES OF SAND
Sand is formed by the weathering of rocks. Based
on the natural sources from which sand is
obtained, it is classified as follows:
forming pits in
It is excavated
from a depth of
about 1-2 m from
the ground level.
This sand is found
as deposits in soil
and it consists of
grains, which are
free from salts.
It serves as an excellent material for mortar or
Pit sand must be made free from clay and other
organic materials before it can be used in mortar.
A coating of oxide of iron over the sand grains
should be removed.
This sand is widely used for all purposes. It is
obtained from the banks or beds of rivers and it
consists of fine rounded grains. The presence of
fine rounded grains is due to mutual attrition
under the action of water current.
The river sand is available in clean conditions.
The river sand is almost white in color.
As it is obtained from sea it contains salt, which is
used in attracting moisture from atmosphere.
absorption causes dampness and
disintegration of work.
It is generally not used for engineering purpose
due to its retards setting action of cement. It is
normally used for non structural purposes.
Crushed Stone Sand / Artificial
It is a substitute for River Sand, fine aggregates
which manufactured by crushing either granite or
basalt rock using 3 stage crushing process.
This sand is manufactured in conformance to IS
Codes and is an effective alternative to river
CLASSIFICATION OF SAND
Based on the grain size distribution
Fine sand: The sand passing through a sieve with
clear openings of 1.5875 mm is known as fine sand.
Fine sand is mainly used for plastering. .
Coarse sand: The sand passing through a sieve with
clear openings of 3.175 mm is known as coarse sand.
It is generally used for masonry work.
Gravelly sand: The sand passing through a sieve with
clear openings of 7.62 mm is known as gravelly sand.
It is generally used for concrete work.
Grading of sand:
On the basis of particle size, fine aggregate is
graded into four zones.
Percentage passing for
Grading Zone Grading
90 – 100
90 – 100
90 – 100
90 – 100
60 – 95
75 – 100
85 – 100
95 – 100
30 – 70
55 – 90
75 – 100
90 – 100
15 – 34
35 – 59
60 – 79
80 – 100
5 – 20
8 – 30
12 – 40
15 – 50
0 – 10
0 – 10
0 – 10
0 – 15
Sand for Construction Works
Different construction works require different
standards of sand for construction.
• Brick Works: finest modulus of fine sand should be
1.2 to 1.5 and silt contents should not be more than
• Plastering Works: finest modulus of fine sand should
not be more than 1.5 and silt contents should not be
more than 4%.
• Concreting Works: coarse sand should be used with
finest modulus 2.5 to 3.5 and silt contents should not
be more than 4%.
PROPERTIES OF GOOD SAND
It should be clean and coarse.
It should be free from any organic or vegetable
matter; usually 3-4 per cent clay is permitted.
It should be chemically inert.
It should contain sharp, angular, coarse and durable
It should not contain salts which attract moisture from
It should be well graded, i.e., it should contain
particles of various sizes in suitable proportions.
It should be strong and durable.
It should be clean and free from coatings of clay and
To check the quality of fine aggregates or sand;
put some quantity of sand in a glass of water.
Then it is vigorously shaken and allowed to settle.
If the clay is present in sand, its distinct layer is
formed at the top of sand.
To detect the presence of organic impurities in
sand, a solution of sodium hydroxide or caustic
soda is added to sand and stirred. If the color of
solution changes into brown, it shows presence of
BULKING OF SAND
The increase in the volume of sand due to the
presence of moisture is known as bulking of sand.
This is due to the fact that moisture forms a film of
water around the sand particles and this results in an
increase in the volume of sand. The extent of bulking
depends on the grading of sand. The finer the
material the more will be the increase in volume for
the given moisture content.
For a moisture content of 5–8 per cent, the increase
in volume may be about 20–40 per cent depending
upon the gradation of sand. When the moisture
content is further increased, the sand particles pack
near each other and the amount of bulking is
decreased. Hence, dry sand and the sand completely
Deleterious materials in sand
Sand shall not contain any harmful impurities such as
iron, pyrites, alaklies, salts, coal or other organic
impurities, mica, shale or similar laminated materials,
soft fragments, sea shale in such form or in such
quantities as to affect adversely the hardening,
strength or durability of the mortar. The maximum
quantities of clay, fine silt, fine dust and organic
impurities in the sand / marble dust shall not exceed
the following limits:
(a) Clay, fine silt and fine dust when determined in
accordance within not more than 5% by mass in IS
2386 (Part-II), natural sand or crushed gravel sand
and crushed stone sand.
(b) Organic impurities when determined in color of the
liquid shall be lighter in lighter in accordance with IS
2386 (Part –II) than that specified in the code.