SONARGAON UNIVERSITY

COURSE TEACHER: GROUP LEDER ……..…………………………… ……………………………………

WELCOME TO THE PRESENTATIO ON

CE - DETAILS OF CONSTRUCTION

TOPICS: SAND

SL NAME ID E-mail

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02 Md.Nurul islma 1601007174 md.nurul976@gamal.com

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GROUP: 02

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.

SAND

Sand is formed by the weathering of rocks. Based on the natural sources from which sand is obtained, it is classified as follwos:

Pit sand River sand Sea sand

SOURCES OF SAND

PIT SAN

D

This sand is obtained by forming pits in soils. 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 sharp angular grains, which are free from salts.

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 mortal. A coating of oxide of iron over the sand grains should be

removed.

PIT SAN

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This sand is widely used for all purpose. 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.

RIVER SAND

This is obtained from sea shores. It is brown in color and it also has the fine

rounded grain.

SEA SAND

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.

SEA SAND

Based on the grain size distribution Fine sand: The sand passing through a sieve with

clear opening of 1.5875 mm is known as fine sand. Coarse Sand: The sand passing through a sieve with

clear opening of 3.175 mm is known as coarse sand. Gravelly sand: The sand passing through a sieve with

clear opening of 7.62 mm is known as Gravelly sand. It is generally used for concrete work

CLASSIFICATION OF SAND

Grading of sand:

IS Sieve Percentage passing for

Grading Zone I Grading Zone II Grading Zone III

Grading Zone IV

10mm 100 100 100 100

4.75 mm 90-100 90-100 90-100 90-100

2.36 mm 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 micron 5-20 8-30 12-40 15-50

150 micron 0-10 0-10 0-10 0-15

• 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 the

atmophere.• 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.

PROPERTIES OF GOOD 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%.

• 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%.

Functions of sand in Mortar/Concrete:

• Offers requisite surface area for the film of binding material to adhere and spread.

• Increases the volume of mortar & consequently makes mortar more economical.

• A well-graded sand adds to the density of mortars and concrete.

• Prevents excessive shrinkage of mortar. • Since inert material, it renders structure more

resistant against atmospheric agencies.

Tests for sand:

If present in sand, it can be ascertained by determining the percentage loss in weight of a sample of sand after washing the same with clean water and then sieving through #200 opening size.

However, field test can be performed by rubbing a small amount of sand between finger tips. If clay spots are left on finger tips, it indicates the existence of clay in the considerable amount.

Test for silt and clay:

Test for silt:Can be tested by putting some amount in mouth. The test will reflect the presence of any salt

Test for Organic matter: Make 3% solution of NaOH and put some sand into the solution. Close the bottle for 24-hrs and meanwhile shake the solution vigorously. The color of the liquid turns brown if any organic matter is present in sand. The darkness of color gives the estimation of the amount of organic matter exists in the salt

Substitute for sand: • If good sand is not available in the nearby of the site, the substitutes may be

used. • Stone screenings: Fine particles obtained by screening crushed stones. The

grains are sharp and strong, and hence impart better strength to the concrete if used.

• Surkhi: Obtained from finely powdered burnt clay (brick). Also obtained by grinding slightly under-burnt bricks. It disintegrates under the action of air & humidity; not used for external mortar.

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, alkalis, salts, coal or other organic impurities, mica, shale or similar laminated materials, soft fragments, sea shale in such quantities as to affect adversely the hardening, strength of 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 nor more than 5% by mass in IS 2386, 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, Than that specified in the code.

THE ENDTHANKS TO ALL