Sand

BUILDING MATERIALS

SAND

Presented by-

Rishabh Dev,Dhir Dhwaj, Anant Nautiyal, Gaurav Soni,

Riya Taneja, Priyvarth Arya

State Institute of Urban Planning and

Architecture

SAND

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.

Classification of sand

Formation

Pit sand

River Sand

Sea Sand

Size of particles

Fine Sand

Coarse Sand

Gravelly Sand

Composition

Clean Sand

Silty Sand

Clayey Sand

Classification on the

basis of formation

PIT SAND

This sand isobtained byforming pits insoils.

It is excavatedfrom a depth ofabout 1-2 m fromthe ground level.

This sand is foundas deposits in soiland it consists ofsharp angulargrains, which arefree from salts.

Pit Sand

It serves as an excellent material for mortar or

concrete work.

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.

RIVER SAND

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.

River sand

The river sand is available in clean conditions.

The river sand is almost white in color.

It is mainly used for plastering. In north India ,

Yamuna banks are a great source of River sand .

River sand

SEA SAND

This is obtained from sea shores.

It is brown in color and it also has the fine

rounded grain.

Sea sand

DREDGED SAND

DESPOSITION

As it is obtained from sea it contains salt, which is

used in attracting moisture from atmosphere.

Such 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.

Sea sand

Crushed Stone Sand / Artificial

Sand

It is a substitute for River Sand, fine aggregates

which manufactured by crushing either granite or

basalt rock using 3 stage crushing process.

Classification on the

basis of size of particles

Fine sand

The sand passing through a sieve with clear openings of 1.5mm is

known as fine sand. Fine sand is mainly used for plastering.

Coarse Sand

The sand passing through a sieve with clear openings of 3.5mm is

known as Coarse Sand. Coarse Sand is generally used for masonry

work.

Gravelly Sand

The sand passing through the sieve of 7.62mm 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. IS Sieve Percentage passing for

Grading Zone

I

Grading

Zone II

Grading

Zone III

Grading

Zone IV

10mm 100 100 100 100

4.75mm 90 – 100 90 – 100 90 – 100 90 – 100

2.36mm 60 – 95 75 – 100 85 – 100 95 – 100

1.18 mm 30 – 70 55 – 90 75 – 100 90 – 100

600 micron 15 – 34 35 – 59 60 – 79 80 – 100

300 microns 5 – 20 8 – 30 12 – 40 15 – 50

150 microns 0 – 10 0 – 10 0 – 10 0 – 15

Classification of Sand

on the basis of

composition

Clean Sand

•These are well graded sand containing mostly quartz

(SiO2)

•It is free from any organic or inorganic impurities

•It is perfect for construction purposes

Silty Sand

•These are poorly graded sand with considerable amount

of Silt

•The size of silt particles are very small and form lump

•Not good for construction purpose

Clayey Sand

This sand have prominent clay fraction and plastic

fines.

Traditionally used for the construction of walls

Also used as mortar for bricks because of its high

adhesive property

Use of sand in

construction

1) Bricks work – Finest modulus of fine sand. The size of grains must be

between 1.2 – 1.5 mm. it is formed by mixing clay and sand with small

quantities of lime magnesia and iron oxide. Sand gives more shapely and

uniform texture to the bricks. An excess of sand, however render the bricks

too brittle and destroys cohesion. 25% of sand is said to be a good

proportion.

2) Plastering work – Finest modulus of fine sand which have grain size not less

than 1.5mm. It is usually mixed with cement in the ratio of 1:3 or 1:4.

- It is the basic material for every construction. Most of the raw material for

construction consists of some ratio of sand.

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

4%. Finest modulus of fine sand. The size of grains

must be between 1.2 – 1.5 mm. it is formed by mixing

clay and sand with small quantities of lime magnesia

and iron oxide. Sand gives more shapely and uniform

texture to the bricks. An excess of sand, however

render the bricks too brittle and destroys cohesion.

25% of sand is said to be a good proportion.

• 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%.

3) Mortars and concrete work – Sand is used in

mortar and concretes for the following purposes :-

a) Strength – It helps in the adjustment of strength

of mortar or concrete by variation of its proportion

with cement or lime. It also increases the

resistance of mortar against crushing.

SOIL BEARING CAPACITY Bearing capacity is the power of foundation soil to

hold the forces from the superstructure without

undergoing shear failure or excessive settlement.

Foundation soil is that portion of ground which is

subjected to additional stresses when foundation and

superstructure are constructed on the ground. The

following are a few important terminologies related to

bearing capacity of soil

Ultimate Bearing Capacity (qf) : It is the maximum

pressure that a foundation soil can withstand without

undergoing shear failure

Net ultimate Bearing Capacity (qn) : It is the maximum

extra pressure (in addition to initial overburden

pressure) that a foundation soil can withstand without

undergoing shear failure

a) Bulk – It act as an adulterant. Hence, the bulk

volume of mortar is increased which results in

reduction of cost.

c) Setting – In the case of fat lime, CO2 is absorbed

through the voids of sand and setting of lime

occurs effectively.

d) Shrinkage – It prevents excessive shrinkage of

mortar in the course of drying. Hence, the

cracking of mortar during setting is avoided.

e) Surface area - It subdivides the paste of the

binding material into a thin film and thus, more

surface area is offered for its spreading and

adhering.

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 grains.

It should not contain salts which attract moisture from the atmosphere.

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 silt.

Tests1) Sieve test – Sand is filtered through sieve of suitable

pore size. If the residue left is more than the filteredsand then the sand is of poor quality.

2) Take some quantity of sand in water. Then, shake itvigorously and allow it to settle down. If the clay andsilt is present in sand , its distinct layer is formed atthe top of water. The sand is acceptable if the amountof clay and silt present is not more than 5% than thetotal mixture.

3) To detect the presence of organic material in thesand, add NaOH or Caustic Soda to it. If the colourchanges to brown, then the sand has organicimpurities.

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

flooded with water have practically the same volume.

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.

Transportation of sand

It is usually transported in trucks or trolleys from the digging

sites to the construction sites as it is required in bulk amount.

It is measured in cubic feet.

length

height

Substitutes of Sand

Sand has now become a scarce material and extraction of

river sand is now said to affect the ecological balance. The

use of substitutes for sand has gained greater importance.

Surkhi, or finely grained burnt clay, is one of the materials

used for this purpose. It can be used in all mortars except

that for plastering.

Processed quarry dust or stone screening is also being

used as substitutes. It is abundantly available and if it is

properly screened, it imparts more strength to the mortar.

This is now being industrially manufactured.

references

http://theconstructor.org/concrete/joints-in-

concrete-structures/970/

http://www.wikihow.com/Make-Concrete

THANK YOU