Manual_ConcreteTech.pdf

7/23/2019 Manual_ConcreteTech.pdf

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Department of Civil Engineering

Sanjay Ghodawat Group of Institutions, Atigre, Kolhapur

1Lab Manual of

Concrete Technology

Prepared By

Chetan S. PatilAssistant Professor


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2

Introduction :

The behavior and properties of structural materials, e.g. concrete, asphalt and steel can be better

understood by detailed, well-designed, first hand experience with these materials. The students will

become familiar with the nature and properties of these materials by conducting laboratory tests.These tests have been selected to illustrate the basic properties and methods of testing of cement,

aggregates, paste, mortar, concrete, asphalt and steel. Test procedures, sometimes simplified because of

time limitation, are mostly those outlined by the Indian Standards.

Course Objectives

1. To prepare the students to effectively link theory with practice and application and to demonstrate

background of the theoretical aspects.

2. To prepare the students to generate and analyze data using experiments and to apply elements of data

statistics.

3. To prepare the students to have hands on experiments and to have exposure to equipment and

machines

4. To prepare the students to solve problems including design elements and related to their course work.

5. To encourage the students to use computers in analyzing the data.

6.

To emphasize the knowledge and application of safety regulations.

Student Responsibilities

1. In the very beginning of the laboratory work, the students will be organized into groups. For this

reason, regular attendance is strictly required.

2. Every laboratory session is divided into two parts. In the first part, the instructor will be lecturing on

the test objective, procedure and data collection. In the second part, the students, organized in groups,

are required to conduct the field work. In order to perform the field work within the assigned period,

and to gain the maximum benefit from the field work, the students must familiarize themselves with

the purpose, objective, and procedure of the experiment before coming to the laboratory. Relevant

lecture notes and laboratory manual should be studied carefully and thoroughly.

3. At the end of the test, every group should submit a draft sheet of the data collected for approval by the

instructor.

4. It should be understood that laboratory facilities and instruments are provided to enhance the learning

process and to give first hand experience of surveying.

5. The instruments and tools must be properly cared and cleaned during and after every laboratory


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3session. Also, students should always take precautions to avoid any possible hazards. Students mustfollow laboratory regulations provided at the end of this section.

Report Writing

Every student is required to submit his own separate report for each test conducted. Reports

should be writing on 8 x 11 in. high-quality paper. In general, the reports should be arranged in the

following order:

Laboratory Regulations

1. Make sure that you know the location of Fire Extinguishers, First Aid Kit and Emergency Exits before

you start your experiments.

2. Get First Aid immediately for any injury, no matter how small it is.

3. Do not wear loose dress

4. Always use close shoes (i.e. safety or boots)

5. Do not play with valves, screws and nuts

6. Do not try to run and operate any machine without permission and knowledge of the lab. personnel

List of Experiment as per Shivaji University Curriculum

Sr.

No.Name of Experiment

Page No

From To

1. Testing of cement: Consistency, fineness, setting time, Specific Gravity,

Soundness and strength.

2. Testing of fine aggregate: Specific Gravity, sieve analysis and zoning, bulking of

fine aggregate, bulk density, silt content.

3. Testing of coarse aggregate: Specific Gravity, sieve analysis, bulk density,

flakiness index, elongation index, water absorption & moisture content, soundness

of aggregate.

4. Concrete Mix design by ACI 211.1-91 method, IS code method as per 10262-

2007 & 456-2000, DOE method

5. Tests on Concrete- Workability tests Slump cone test, compaction factor test,

Vee-bee consistometer test, flow table test, strength tests- compressive strength,

flexural strength, split tensile strength.

6. Effects of Admixture - Accelerator, Retarder, Super Plasticizer.

7. Nondestructive Testing - Rebound Hammer test, Ultrasonic Pulse Velocity test.


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4Experiment No. : 01(a) Date

Title : Determination of Consistency of Standard Cement Paste

Objective : To determine the normal consistency of a given sample of cement.

Reference : IS : 4031 ( Pat 4 ) - 1988, IS : 5513-1976,

Theory :

For finding out initial setting time, final setting time and soundness of cement, and strength a parameter

known as standard consistency has to be used. The standard consistency of a cement paste is defined as

that consistency which will permit a Vicat plunger having 10 mm diameter and 50 mm length to penetrate

to a depth of 33-35 mm from the top of the mould.

Apparatus :

Vicat apparatus conforming to IS : 5513-1976, Balance, Gauging Trowel, Stop Watch, etc.

Procedure :

1.

The standard consistency of a cement paste is defined as that consistency which will permit the Vicat

plunger to penetrate to a point 5 to 7 mm from the bottom of the Vicat mould

2. Initially a cement sample of about 300 g is taken in a tray and is mixed with a known percentage of

water by weight of cement, say starting from 26% and then it is increased by every 2% until the normal

consistency is achieved.

3. Prepare a paste of 300 g of Cement with a weighed quantity of potable or distilled water, taking care

that the time of gauging is not less than 3 minutes, nor more than 5 min, and the gauging shall be

completed before any sign of setting occurs. The gauging time shall be counted from the time of

adding water to the dry cement until commencing to fill the mould.

4. Fill the Vicat mould (E) with this paste, the mould resting upon a non-porous plate. After completely

filling the mould, smoothen the surface of the paste, making it level with the top of the mould. The

mould may be slightly shaken to expel the air.

5. Place the test block in the mould, together with the non-porous resting plate, under the rod bearing the

plunger; lower the plunger gently to touch the surface of the test block, and quickly release, allowing it

to sink into the paste. This operation shall be carried out immediately after filling the mould.

6. Prepare trial pastes with varying percentages of water and test as described above until the amount of


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5water necessary for making up the standard consistency as defined in Step 1 is found.Figure :

Observation :

Express the amount of water as a percentage by mass of the dry cement to the first place of decimal.

Sr. No.Weight of cement

(gms)

Percentage by

water of dry

Cement (%)

Amount of

water added

(ml)

Penetration

(mm)

1

2

3

4

Conclusion / R : The normal consistency of a given sample of cement is _ _ _ _ %


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6Experiment No. : 01(b) Date

Title : Determination of Setting Time of Standard Cement Paste

Objective : To determine the initial and final setting time of a given sample of cement.

Reference : IS : 4031 ( Pat 4 ) -1988, IS : 4031 ( Pat 5 ) - 1988, IS : 5513-1976,

Theory :

For convenience, initial setting time is regarded as the time elapsed between the moments that the water is

added to the cement, to the time that the paste starts losing its plasticity. The final setting time is the time

elapsed between the moment the water is added to the cement, and the time when the paste has completely

lost its plasticity and has attained sufficient firmness to resist certain definite pressure.

Apparatus :

Vicat apparatus conforming to IS : 5513-1976, Balance, Gauging Trowel, Stop Watch, etc.

Procedure :

1.

Preparation of Test Block -Prepare a neat 300 gms cement paste by gauging the cement with 0.85

times the water required to give a paste of standard consistency. Potable or distilled water shall be used

in preparing the paste.

2. Start a stop-watch at the instant when water is added to the cement. Fill the Vicat mould with a cement

paste gauged as above, the mould resting on a nonporous plate. Fill the mould completely and smooth

off the surface of the paste making it level with the top of the mould.

3.

Immediately after moulding, place the test block in the moist closet or moist room and allow it to

remain there except when determinations of time of setting are being made.

4. Determination of Initial Setting Time- Place the test block confined in the mould and resting on the

non-porous plate, under the rod bearing the needle ( C ); lower the needle gently until it comes in

contact with the surface of the test block and quickly release, allowing it to penetrate into the test block

5.

Repeat this procedure until the needle, when brought in contact with the test block and released as

described above, fails to pierce the block beyond 5.0 0.5 mm measured from the bottom of the mould

shall be the initial setting time.

6.

Determination of Final Setting Time -Replace the needle (C) of the Vicat apparatus by the needlewith an annular attachment (F).


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77. The cement shall be considered as finally set when, upon applying the needle gently to the surface ofthe test block, the needle makes an impression thereon, while the attachment fails to do so.

8.

The period elapsing between the time when water is added to the cement and the time at which the

needle makes an impression on the surface of test block while the attachment fails to do so shall be the

final setting time.

Figure :

Observation :

1. Weight of given sample of cement is _ _ _ _ gms

2.

The normal consistency of a given sample of cement is _ _ _ _ %

3.

Volume of water addend (0.85 times the water required to give a paste of standard consistency) for

preparation of test block _ _ _ _ ml

Sr. No.Setting Time

(Sec)

Penetration

(mm)Remark

1

2

3

Conclusion / Result : i) The initial setting time of the cement sample is found to be ..ii) The final setting time of the cement sample is found to be ..


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8Experiment No. : 01(c) Date

Title : Determination of Fineness of Cement by dry sieving

Objective : To determine the normal consistency of a given sample of cement.

Reference : IS : 4031 ( Pat 1 ) - 1988,

Theory :

The fineness of cement has an important bearing on the rate of hydration and hence on the rate of gain of

strength and also on the rate of evolution of heat. Finer cement offers a greater surface area for hydration

and hence faster the development of strength, (Fig. 3). The fineness of grinding has increased over the

years. But now it has got nearly stabilized. Different cements are ground to different fineness. The particle

size fraction below 3 microns has been found to have the predominant effect on the strength at one day

while 3-25 micron fraction has a major influence on the 28 days strength. Increase in fineness of cement is

also found to increase the drying shrinkage of concrete.

Fineness of cement is tested in two ways :

(a) By sieving.

(b) By determination of specific surface (total surface area of all the particles in one gram of cement) by

air-permeability apparatus. Expressed as cm2/gm or m2/kg. Generally Blaine Air permeability apparatus is

used.

Apparatus : Test Sieve 90 microns, Balance, Gauging Trowel, Brush, etc.

Procedure :


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91. Fit the tray under the sieve, weigh approximately 10 g of cement to the nearest 0.01 g and place it onthe sieve, being careful to avoid loss. Fit the lid over the sieve. Agitate the sieve by swirling, planetary

and linear movement until no more fine material passes through it.

2. Remove and weigh the residue. Express its mass as a percentage, R1, of the quantity first placed in the

sieve to the nearest 0.1 percent. Gently brush all the fine material off the base of the sieve into the tray.3. Repeat the whole procedure using a fresh 10 g sample to obtain R2. Then calculate the residue of the

cement R as the mean of R1, and R2, as a percentage, expressed to the nearest 0.1 percent.

4. When the results differ by more than 1 percent absolute, carry out a third sieving and calculate the

mean of the three values.

Conclusion / R : The fineness of a given sample of cement is _ _ _ _ %

Experiment No. : 01(d) Date

Title : Determination of Soundness of Cement by Le-Chatelier method

Objective : To determine the soundness of a given sample of cement by Le-Chatelier

method.

Reference : IS : 4031 ( Pat 3 ) - 1988,

Theory :

It is very important that the cement after setting shall not undergo any appreciable change of volume.

Certain cements have been found to undergo a large expansion after setting causing disruption of the set

and hardened mass. This will cause serious difficulties for the durability of structures when such cement is

used. The unsoundness in cement is due to the presence of excess of lime than that could be combined with

acidic oxide at the kiln. It is also likely that too high a proportion of magnesium content or calcium

sulphate content may cause unsoundness in cement. Soundness of cement may be determined by two

methods, namely Le-Chatelier method and autoclave method

Apparatus :

Le- Chatelier test apparatus conform to IS : 5514-1969, Balance, Gauging Trowel, Water Bath etc.

Procedure :


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101. Place the lightly oiled mould on a lightly oiled glass sheet and fill it with cement paste formed bygauging cement with 0.78 times the water required to give a paste of standard consistency [see IS :

4031 (Part 4)-1988 or experiment No. 1(a) ].

2. The paste shall be gauged in the manner and under the conditions prescribed in experiment No.1,

taking care to keep the edges of the mould gently together while this operation is being performed.

3. Cover the mould with another piece of lightly oiled glass sheet, place a small weight on this covering

glass sheet and immediately submerge the whole assembly in water at a temperature of 27 2C and

keep there for 24 hours.

4. Measure the distance separating the indicator points to the nearest 0.5 mm. Submerge the mould again

in water at the temperature prescribed above.

5. Bring the water to boiling, with the mould kept submerged, in 25 to 30 minutes, and keep it boiling for

three hours. Remove the mould from the water, allow it to cool and measure the distance between the

indicator points.

6. The difference between these two measurements indicates the expansion of the cement. This must not

exceed 10 mm for ordinary, rapid hardening and low heat Portland cements. If in case the expansion is

more than 10 mm as tested above, the cement is said to be unsound.

Figure :

Observation :

Express the amount of water as a percentage by mass of the dry cement to the first place of decimal.


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11

Sr. No.

Distance separating the

indicator submerge in

normal temp water for

24 hours

Distances separating the

indicator submerge in

boiling for three hours.

The difference

between these two

measurements

Remark

1

2

3

4

Conclusion / R : The given cement is said to be sound / unsound.


Title : Determination of Compressive Strength of Cement

Objective : To determine the compressive strength of a given sample of cement.

Reference : IS : 4031 ( Pat 6 ) - 1988, IS : 10080-1982, IS : 650-1966, IS: 269-1976

Theory :

The compressive strength of hardened cement is the most important of all the properties. Therefore, it is

not surprising that the cement is always tested for its strength at the laboratory before the cement is used in

important works. Strength tests are not made on neat cement paste because of difficulties of excessive

shrinkage and subsequent cracking of neat cement.

Apparatus :

The standard sand to be used in the test shall conform to IS : 650-1966, Vibration Machine, Poking Rod,

Cube Mould of 70.6 mm size conforming to IS : 10080-1982, Balance, Gauging Trowel, Stop Watch,Graduated Glass Cylinders, etc.

Procedure :

1. Preparation of test specimens - Clean appliances shall be used for mixing and the temperature of water

and that of the test room at the time when the above operations are being performed shall be 27 2C.

Potable/distilled water shall be used in preparing the cubes.

2.The material for each cube shall be mixed separately and the quantity of cement, standard sand andwater shall be as follows:


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12Cement 200 g and Standard Sand 600 g

Water

3.0

4

Ppercent of combined mass of cement and sand, where P is the percentage of water

required to produce a paste of standard consistency determined as described in IS : 4031 (Part 4)-1988

or Experiment No.1(a).

3. Place on a nonporous plate, a mixture of cement and standard sand. Mix it dry with a trowel for one

minute and then with water until the mixture is of uniform colour. The quantity of water to be used

shall be as specified in step 2. The time of mixing shall in any event be not less than 3 min and should

the time taken to obtain a uniform colour exceed 4 min, the mixture shall be rejected and the operation

repeated with a fresh quantity of cement, sand and water.

4. Moulding Specimens - In assembling the moulds ready for use, treat the interior faces of the mould

with a thin coating of mould oil.

5.

Place the assembled mould on the table of the vibration machine and hold it firmly in position by

means of a suitable clamp. Attach a hopper of suitable size and shape securely at the top of the mould

to facilitate filling and this hopper shall not be removed until the completion of the vibration period.

6. Immediately after mixing the mortar in accordance with step 1 & 2, place the mortar in the cube mould

and prod with the rod. Place the mortar in the hopper of the cube mould and prod again as specified for

the first layer and then compact the mortar by vibration.

7. The period of vibration shall be two minutes at the specified speed of 12 000 400 vibration per

minute.

8. At the end of vibration, remove the mould together with the base plate from the machine and finish the

top surface of the cube in the mould by smoothing the surface with the blade of a trowel.

9. Curing Specimens - keep the filled moulds in moist closet or moist room for 24 1 hour after

completion of vibration. At the end of that period, remove them from the moulds and immediately

submerge in clean fresh water and keep there until taken out just prior to breaking.

10.The water in which the cubes are submerged shall be renewed every 7 days and shall be maintained at

a temperature of 27 2C. After they have been taken out and until they are broken, the cubes shall not

be allowed to become dry.

11.Test three cubes for compressive strength for each period of curing mentioned under the relevant

specifications (i.e. 3 days, 7 days, 28 days)

12.The cubes shall be tested on their sides without any packing between the cube and the steel plattens of

the testing machine. One of the plattens shall be carried on a base and shall be self-adjusting, and the

load shall be steadily and uniformly applied, starting from zero at a rate of 35 N/mm2/min.

Figure :


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13

Observation :

Sr. No.Age of

Cube

Weight of

Cement Cube(gms)

Cross-

Sectionalarea (mm2)

Load (N)

Compressive

strength(N/mm2)

Average

Compressivestrength (MPa)

1

7 Days2

3

4

28 Days5 `

6

Calculation :

The measured compressive strength of the cubes shall be calculated by dividing the maximum load applied

to the cubes during the test by the cross-sectional area, calculated from the mean dimensions of the section

and shall be expressed to the nearest 0.5 N/mm2. In determining the compressive strength, do not consider

specimens that are manifestly faulty, or that give strengths differing by more than 10 percent from the

average value of all the test specimens.

Conclusion / Result :

i) The average 3 Days Compressive Strength of given cement sample is found to be ....

ii) The average 7 Days Compressive Strength of given cement sample is found to be ....

iii) The average 28 Days Compressive Strength of given cement sample is found to be ....


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14

Experiment No. : 02(a) Date

Title : Particle Size Distribution of Fine Aggregates

Objective : To determine fineness modulus of fine aggregate and classifications based on

IS: 383-1970

Reference : IS : 2386 ( Part I)1963, IS: 383-1970, IS : 460-1962

Theory :

This is the name given to the operation of dividing a sample of aggregate into various fractions each

consisting of particles of the same size. The sieve analysis is conducted to determine the particle size

distribution in a sample of aggregate, which we call gradation. Many a time, fine aggregates are designated

as coarse sand, medium sand and fine sand. These classifications do not give any precise meaning. What

the supplier terms as fine sand may be really medium or even coarse sand. To avoid this ambiguity

fineness modulus could be used as a yard stick to indicate the fineness of sand.

The following limits may be taken as guidance: Fine sand : Fineness Modulus : 2.2 - 2.6, Medium sand :

F.M. : 2.6 - 2.9, Coarse sand : F.M. : 2.9 - 3.2Sand having a fineness modulus more than 3.2 will be unsuitable for making satisfactory concrete.


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15

Apparatus :

Test Sieves conforming to IS : 460-1962 Specification of 4.75 mm, 2.36 mm, 1.18 mm, 600 micron, 300

micron, 150 micron, Balance, Gauging Trowel, Stop Watch, etc.

Procedure :

1. The sample shall be brought to an air-dry condition before weighing and sieving. The air-dry sample

shall be weighed and sieved successively on the appropriate sieves starting with the largest. Care shall

be taken to ensure that the sieves are clean before use.

2. The shaking shall be done with a varied motion, backward sand forwards, left to right, circular

clockwise and anti-clockwise, and with frequent jarring, so that the material is kept moving over the

sieve surface in frequently changing directions.

3. Material shall not be forced through the sieve by hand pressure. Lumps of fine material, if present, may

be broken by gentle pressure with fingers against the side of the sieve.

4. Light brushing with a fine camel hair brush may be used on the 150-micron and 75-micron IS Sieves to

prevent aggregation of powder and blinding of apertures.

5. On completion of sieving, the material retained on each sieve, together with any material cleaned from

the mesh, shall be weighed.

Observation :

I S Sieve

Weight

Retained on

Sieve (gms)

Percentage of

Weight Retained

(%)

Percentage of

Weight Passing

(%)

Cumulative

Percentage of

Passing (%)

Remark

4.75 mm

2.36 mm

1.18 mm

600 micron

300 micron

150 micron

Total

Calculation :

Fineness modulus is an empirical factor obtained by adding the cumulative percentages of aggregate

retained on each of the standard sieves ranging from 4.75 mm to 150 micron and dividing this sum by an


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16arbitrary number 100.

100

(%)PassingofPercentageCumulativeofTotalModulusFiness FM,


i) Fineness modulus of a given sample of fine aggregate is .. that indicate Coarse sand/ Medium sand/

Fine sand.

ii) The given sample of fine aggregate is belong to Grading Zones I / II / III / IV

Experiment No. : 02(b) Date

Title : Determination of Bulking of Fine Aggregate

Objective : To determine bulking of a given sample of fine aggregate.

Reference : IS : 2386 ( Part III ) - 1963

Theory :

Free moisture forms a film around each particle. This film of moisture exerts what is known as surface

tension which keeps the neighbouring particles away from it. Similarly, the force exerted by surface

tension keeps every particle away from each other. Therefore, no point contact is possible between the

particles. This causes bulking of the volume. It is interesting to note that the bulking increases with the

increase in moisture content upto a certain limit and beyond that the further increase in the moisture

content results in the decrease in the volume and at a moisture content representing saturation point, the


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17fine aggregate shows no bulking.

Apparatus : Measuring jar, Taping rod etc.

Procedure :

1. Put sufficient quantity of the sand loosely into a container. Level off the top of the sand and pushing

a steel rule vertically down through the sand at the middle to the bottom, measure the height.

Suppose this is h1cm.

2. Empty the sand out of the container into another container where none of it will be lost. Half fill the

first container with water. Put back about half the sand and rod it with a steel rod, about 6 mm in

diameter, so that its volume is reduced to a minimum. Then add the remainder of the sand and rod it

in the same way.

3. The percentage of bulking of the sand due to moisture shall be calculated from the formula:

10011

h

hBulkingPercentage

Conclusion / Result : Bulking of a given sample of fine aggregate is found to be . %

Experiment No. : 02(c) Date

Title : Determination of Silt Content in Fine Aggregate

Objective : To determine silt content in a given sample of fine aggregate by sedimentation

method.

Reference : IS : 2386 ( Part II ) - 1963


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18

Theory :

This is a gravimetric method for determining the clay, fine silt and fine dust, which includes particles up to

20 micron. Differences in the nature and density of materials or in the temperature at the time of testing

may vary the separation point.

Apparatus :

A watertight screw-topped glass jar of dimensions similar to a 1-kg fruit preserving jar, A device for

rotating the jar about its long axis, with this axis horizontal, at a speed of 80 20 rev/min, A sedimentation

pipette, A 1 000-ml measuring cylinder, scale, well-ventilated oven, Taping rod etc.

Chemical :

A solution containing 8 g of sodium oxalate per liter of distilled water shall be taken. For use, this stock

solution is diluted with distilled water to one tenth (that is 100 ml diluted with distilled water to one liter).

Figure :

Procedure :

1.

Approximately 300 g of the sample in the air-dry condition, passing the 4.75-mm IS Sieve, shall be

weighed and placed in the screw-topped glass jar, together with 300 ml of the diluted sodium oxalate


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19solution. The rubber washer and cap shall be fixed, care being taken to ensure water tightness.2. The jar shall then be rotated about its long axis, with this axis horizontal, at a speed of 80 20

rev/min for a period of 15 minutes

3. At the end of 15 minutes, the suspension shall be poured into the 1 000-ml measuring cylinder and

the residue washed by gentle swirling and decantation of successive 150-ml portions of sodiumoxalate solution, the washings being added to the cylinder until the volume is made up to 1000 ml.

4. The suspension in the measuring cylinder shall be thoroughly mixed by inversion and the tube and

contents immediately placed in position under the pipette.

5. The pipette A shall then be gently lowered until the tip touches the surface of the liquid, and then

lowered a further 10 cm into the liquid.

6. Three minutes after placing the tube in position, the pipette A and the bore of tap B shall be filled by

opening B and applying gentle suction at C.

7. A small surplus may be drawn up into the bulb between tap B and tube C, but this shall be allowed to

run away and any solid matter shall be washed out with distilled water from E.

8. The pipette shall then be removed from the measuring cylinder and its contents run into a weighed

container, any adherent solids being washed into the container by distilled water from E through the

tap B.

9. The contents of the container shall be dried at 100 to 110C to constant weight, cooled and weighed.

10.

Calculations The proportion of fine silt and clay or fine dust shall then be calculated from the

following formula:

solutiondilutedtheoflitreoneinoxalatesodiumofgweight in=0.8

andpipette,theofmlinvolume=V

residue,driedtheofgweight in=W

sample,originaltheofgweight in=W

dustfineorsiltfineandclayofPercentage

2

1

8.0

1000100 2

1 V

W

W


The clay, fine silt and fine dust content of given sample of fine aggregate is found to be . %


Title : Determination of Specific Gravity of Fine Aggregate


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20Objective : To determine specific gravity of a given sample of fine aggregate.


Apparatus :Pycnometer, A 1 000-ml measuring cylinder, well-ventilated oven, Taping rod, Filter papers and funnel,

etc.

Figure :

Procedure :

1. A sample of about 500 g shall be placed in the tray and covered with distilled water at a temperature

of 22 to 32C. Soon after immersion, air entrapped in or bubbles on the surface of the aggregate shall

be removed by gentle agitation with a rod. The sample shall remain immersed for 24 l/2 hours.

2.

The water shall then be carefully drained from the sample, by decantation through a filter paper, anymaterial retained being return& to the sample. The fine aggregate including any solid matter retained

on the filter paper shall be exposed to a gentle current of warm air to evaporate surface moisture and

the material just attains a free-running condition. The saturated and surface-dry sample shall be

weighed (weight A).

3. The aggregate shall then be placed in the pycnometer which shall be filled with distilled water. Any

trapped air shall be eliminated by rotating the pycnometer on its side, the hole in the apex of the cone

being covered with a finger. The pycnometer shall be dried on the outside and weighed (weight B).4. The contents of the pycnometer shall be emptied into the tray, care being taken to ensure that all the


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21aggregate is transferred. The pycnometer shall be refilled with distilled water to the same level asbefore, dried on the outside and weighed (weight C).

5. The water shall then be carefully drained from the sample by decantation through a filter paper and

any material retained returned to the sample. The sample shall be placed in the oven in the tray at a

temperature of 100 to 110C for 24 f l/2 hours, during which period it shall be stirred occasionally to

facilitate drying. It shall be cooled in the air-tight container and weighed (weight D).

6. CalculationsSpecific gravity, apparent specific gravity and water &sorption shall be calculated as

follows:

sample.dried-ovenofgweight inD

andonly,waterdistilledwithfilledjaror gaspycnometerofgweight inC

water,distilledwithfilledandsamplecontainingjaror gaspycnometerofgweight inB

sample,dry-surfacesaturatedofgweight inA

rptionWater Abso

GravitySpecifcApparent

GravitySpecifc

D

DA

CBD

D

CBA

D

100


i) The Specific Gravity of a given sample of fine aggregate is found to be .

ii) The Water Absorption of a given sample of fine aggregate is found to be . %

Experiment No. : 03 (a) Date

Title : Determination of Specific Gravity of Course Aggregate

Objective : To determine specific gravity of a given sample of course aggregate.


Apparatus :

A wire basket of not more than 6-3 mm mesh, A stout watertight container in which the basket may befreely suspended, well-ventilated oven, Taping rod, An airtight container of capacity similar to that of the


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22basket, etc.

Figure :

Procedure :

1. A sample of not less than 2000 g of the aggregate shall be thoroughly washed to remove finer

particles and dust, drained and then placed in the wire basket and immersed in distilled water at a

temperature between 22C to 32C with a cover of at least 5 cm of water above the top of the basket.

2. Immediately. after immersion the entrapped air shall be removed from the sample by lifting the

basket containing it 25 mm above the base of the tank and allowing it to drop 25 times at the rate of

about one drop per second. The basket and aggregate shall remain completely immersed during the

operation and for a period of 24 l/2 hours afterwards.

3. The basket and the sample shall then be jolted and weighed in water at a temperature of 22C to

32C (weight A1).

4. The basket and the aggregate shall then be removed from the water and allowed to drain for a few

minutes, after which the, aggregate shall be gently emptied from the basket on to one of the dry

clothes, and the empty basket shall be returned to the water and weighed in water ( weight A 2).

5. The aggregate placed on the dry cloth shall be gently surface dried with the cloth, transferring it to

the second dry cloth when the first will remove no further moisture. The aggregate shall then be

weighed (weight B).

6. The aggregate shall then be placed in the oven in the shallow tray, at a temperature of 100 to 110C

and maintained at this temperature for 24 l/2 hours. It shall then be removed from the oven, cooled

in the airtight container and weighed (weight C).

7. CalculationsSpecific gravity, apparent specific gravity and water &sorption shall be calculated as


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23follows:

in waterbasketemptyofWeightA

in waterbasketandaggregateofWeightA

air.inaggregateovendriedofWeightC

airinaggregatedry-surfacesaturatedtheofWeightB

)A-(Ain wateraggregatesaturatedofWeightA

100AbsorptionWater

GravitySpecifcApparent

GravitySpecifc

2

1

21

CCB

BC

C

BA

C


i) The Specific Gravity of a given sample of course aggregate is found to be .

ii) The Water Absorption of a given sample of course aggregate is found to be . %


Title : Particle Size Distribution of Course Aggregates

Objective : To determination of particle size distribution of coarse aggregates by sieving or

screening.


Theory :

Grading refers to the determination of the particle-size distribution for aggregate. Grading limits and

maximum aggregate size are specified because grading and size affect the amount of aggregate used as

well as cement and water requirements, workability, pumpability, and durability of concrete. In general, if

the water-cement ratio is chosen correctly, a wide range in grading can be used without a major effect on

strength. When gap-graded aggregate are specified, certain particle sizes of aggregate are omitted from the

size continuum. Gap-graded aggregate are used to obtain uniform textures in exposed aggregate concrete.

Close control of mix proportions is necessary to avoid segregation.

Apparatus :


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24Test Sieves conforming to IS : 460-1962 Specification of 80 mm, 40 mm, 20 mm, 10 mm, 4.75 mm,Balance, Gauging Trowel, Stop Watch, etc.

Procedure :

1. The sample shall be brought to an air-dry condition before weighing and sieving. This may be

achieved either by drying at room temperature or by heating at a temperature of 100 to 110C. The

air-dry sample shall be weighed and sieved successively on the appropriate sieves starting with the

largest. Care shall be taken to ensure that the sieves are clean before use.

2. Each sieve shall be shaken separately over a clean tray until not more than a trace passes, but in any

case for a period of not less than two minutes. The shaking shall be done with a varied motion,

backward sand forwards, left to right, circular clockwise and anti-clockwise, and with frequent

jarring, so that the material is kept moving over the sieve surface in frequently changing directions.

3. Material shall not be forced through the sieve by hand pressure. Lumps of fine material, if present,

may be broken by gentle pressure with fingers against the side of the sieve.

4. On completion of sieving, the material retained on each sieve, together with any material cleaned

from the mesh, shall be weighed.

Observation :

I S Sieve

Weight

Retained on

Sieve (gms)

Percentage of

Weight Retained

(%)

Percentage of

Weight Passing

(%)

Cumulative

Percentage of

Passing (%)

Remark

80 mm

40 mm

20 mm

10 mm

4.75 mm

Total



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25


Title : Determination of Flakiness Index and Elongation Index of

Course Aggregates

Objective : To determination of Flakiness Index and Elongation Index of Course

Aggregates.


Theory :

Particle shape and surface texture influence the properties of freshly mixed concrete more than the

properties of hardened concrete. Rough-textured, angular, and elongated particles require more water to

produce workable concrete than smooth, rounded compact aggregate. Consequently, the cement content

must also be increased to maintain the water-cement ratio. Generally, flat and elongated particles are

avoided or are limited to about 15 % by weight of the total aggregate.

Apparatus :

The metal gauge shall be of the pattern shown in Fig. 10.1, Balance, Gauging Trowel, Stop Watch, etc.

Procedure :

1. Sample - A quantity of aggregate shall be taken sufficient to provide the minimum number of 200


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26pieces of any fraction to be tested.2. Sieving - The sample shall be sieved in accordance with the method described in Exp. 3(b) with the

sieves specified in Table 3.18.

3. Separation of Flaky material- Each fraction shall be gauged in turn for thickness on a metal gauge of

the pattern shown in Fig. 11.1, or in bulk on sieves having elongated slots. The width of the slot used

in the gauge or sieve shall be of the dimensions specified in co1 3 of Table 3.18 for the appropriate

size of material.

4.

Weighing of Flaky Material - The total amount passing the gauge shall be weighed to an accuracy of

at least 0.1 percent of the weight of the test sample.

5. The flakiness index is the total weight of the material passing the various thickness gauges or sieves,

expressed as a percentage of the total weight of the sample gauged.

6. Sieving - The sample shall be sieved in accordance with the method described in Exp. 3(b) with the

sieves specified in Table 3.18.

7. Separation of Elongated Material- Each fraction shall be gauged individually for length on a metal

length gauge of the pattern shown in Fig. 11.2. The gauge length used shall be that specified in co1 4

of Table 3.18 for the appropriate size of material.

8. Weighing of Elongated Material - The total amount retained by the length gauge shall be weighed to

an accuracy of at least 0.1 percent of the weight of the test sample.

9. The elongation index is the total weight of the material retained on the various length gauges,

expressed as a percentage of the total weight of the sample gauged.

Figure :


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27

Figure No. 11.1

Figure No. 11.2


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28Observation :1. Total weight of course aggregate. . . . . . . g (Flakiness Index)

Size of Aggregate ThicknessThickness Gauge

mm

Weight

Retained on

Thickness

Gauge

Percentage of

Weight Retained

(%)

RemarkPassing through

IS Sieves

Retained on

IS Sieves

63 mm 50 mm 33.90

50 mm 40 mm 27.00

40 mm 25 mm 19.60

31 mm 25 mm 16.95

25 mm 20 mm 13.50

20 mm 16 mm 10.80

16 mm 12 mm 8.55

12.5 mm 10 mm 6.75

10 mm 6.3 mm 4.89

Total

2. Total weight of course aggregate. . . . . . . g (Elongation Index)

Size of Aggregate Thickness

Length Gaugemm

Weight

Retained on

Length Gauge

Percentage of

Weight Retained

(%)

RemarkPassing through

IS Sieves

Retained on

IS Sieves

63 mm 50 mm --

50 mm 40 mm 81.0

40 mm 25 mm 58.5

31 mm 25 mm --

25 mm 20 mm 40.5

20 mm 16 mm 32.4

16 mm 12 mm 25.6

12.5 mm 10 mm 20.2

10 mm 6.3 mm 14.7

Total

Calculation :

100

(%)GaugeThicknessonRetainedofPercentageofTotalisaggregateanonindexFlakinessThe


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29

100

(%)GaugeLengthonRetainedofPercentageofTotalisaggregateanonindexelongationThe


i) The flakiness index of a given sample of fine aggregate is . %

ii) The elongation index of a given sample of fine aggregate is ..%


Title : Determination of Soundness of Course Aggregates

Objective : To determination of Soundness of Course Aggregates.

Reference : IS : 2386 ( Part V)1963, IS: 383-1970, IS : 460-1962

Theory :

Soundness refers to the ability of aggregate to resist excessive changes in volume as a result of changes in

physical conditions. These physical conditions that affect the soundness of aggregate are the freezing the

thawing, variation in temperature, alternate wetting and drying under normal conditions and wetting and

drying in salt water. Aggregates which are porous, weak and containing any undesirable extraneous

matters undergo excessive volume change when subjected to the above conditions. If concrete is liable to

be exposed to the action of frost, the Soundness refers to the ability of aggregate to resist excessive

changes in volume as a result of changes in physical conditions. Aggregates which are porous, weak and

containing any undesirable extraneous matters undergo excessive volume change when subjected to the

above conditions. Aggregates which undergo more than the specified amount of volume change is said to

be unsound aggregates. If concrete is liable to be exposed to the action of frost, the coarse and fineaggregate which are going to be used should be subjected to soundness test.

Apparatus :

Test Sieves conforming to IS : 460-1962 Specification of 80 mm, 63mm, 50 mm, 40 mm, 31.5 mm, 25

mm, 20 mm, 16 mm, 10 mm, 8.0 mm for Coarse, Drying Oven , Containers, Balance, Gauging Trowel,

Stop Watch, etc.

Chemical :


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301. Sodium Sulphate Solution - Saturated solution of sodium sulphate shall be prepared by dissolvingsodium sulphate, technical grade, conforming to IS : 255 - 1950 Specification for Sodium Sulphate,

Anhydrous, Technical, or an equivalent grade of the salt of either the anhydrous (Na 2SO4) or the

crystalline (Na2SO410H20) form in water at a temperature of 25o to 30C. Sufficient salt shall be added to

ensure not only saturation but also the presence of excess crystals when the solution is ready for use in the

tests. The mixture shall be thoroughly stirred during the addition of the salt and the solution shall be stirred

at frequent intervals until used. The solution shall be cooled to a temperature of 27o2C and maintained at

that temperature for at least 48 hours before use. The solution shall be thoroughly stirred immediately

before use and salt cakes, if any, shall be broken and the specific gravity shall be determined. When used,

the solution shall have a specific gravity of not less than l.151 and not greater than 1.174. Discolored

solution shall be discarded, or filtered and checked for specific gravity.

2. Magnesium Sulphate Solution - The saturated solution of magnesium sulphate shall be made by

dissolving magnesium sulphate, technical grade, conforming to IS : 257 - 1950 Specification for

Magnesium Sulphate (Epsom Salt ), Technical, or an equivalent grade of the salt of either the anhydrous (

MgSO4) or the crystalline ( MgS04.7H2O ) ( epsom salt ) form in water at a temperature of 25 to 30C.

Sufficient quantity of salt shall be added to ensure saturation and the presence of excess crystals when the

solution is ready for use in the tests. The mixture shall be thoroughly stirred during the addition of the salt

and the solution shall be stirred at frequent intervals until used. The solution shall be cooled to a

temperature of 27 1C and maintained at that temperature for at least 48 hours before use. The solution

shall be thoroughly stirred immediately before use and salt cakes, if any, shall be broken up and the

specific gravity shall be determined. When used, the solution shall have a specific gravity of not less than

1.295 and not more than 1.308. Discolored solution shall be discarded, or filtered and checked for specific

gravity.

Procedure :

1. The sample of coarse aggregate shall be thoroughly washed and dried to constant weight at 105C to

110C and shall be separated into different sizes shown in 4.2 by sieving to refusal. The proper

weight of sample for each fraction shall be weighed out and placed in separate containers for the test.

In the case of fractions coarser than the 20-mm IS Sieve, the number of particles shall also be

counted.

2. The samples shall be immersed in the prepared solution of sodium sulphate or magnesium sulphate

for not less than 16 hours nor more than 18 hours in such a manner that the solution covers them to a

depth of at least 15 mm. The samples immersed in the solution shall be maintained at a temperature

of 27 1C for the immersion period.

3. After the immersion period, the aggregate sample shall be removed from the solution, permitted to


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31drain for 15 5 minutes, and placed in the drying oven. The temperature of the oven shall have beenbrought previously to 105 to 110C. During the drying period, the samples shall be removed from

the oven, cooled to room temperature and weighed at intervals of not less than 4 hours nor more than

18 hours. Constant weight may be considered to have been achieved when two successive weights

for any one sample differ by by less than 1.0 g in the case of coarse aggregate samples.

4. After constant weight has been achieved the samples shall be allowed to cool to room temperature,

then they shall again be immersed in the prepared solution as described in step 2.

5. The process of alternate immersion and drying shall be repeated until the specified number of cycles

as agreed to between the purchaser and the vendor is obtained.

Observation :

Nos of Cycle

Weight of aggregate

before in immersed in the

prepared solution

Weight of oven dry aggregate

after in immersed in the

prepared solution

% weight loss of

aggregate after

complete of cycle

1

2

3

4

56

7

8

9

10

Total Weight loss:


As a general guide, it can be taken that the average loss of weight after 10 cycles should not exceed 12 per

cent and 18 per cent when tested with sodium sulphate and magnesium sulphate respectively.

Given sample of aggregate is sound/unsound


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32Experiment No. : 3(e) Date

Title : Determination of Aggregate Crushing value

Objective : This method of test covers the procedure for determining the aggregate crushing

value of coarse aggregate.

Reference : IS : 2386 ( Part IV)1963, IS: 383-1970

Theory :

The aggregate crushing value gives a relative measure of the resistanceof an aggregate to crushing under

a gradually applied compressive load. With aggregate of aggregate crushing value 30 or higher, the result

may be anomalous, and in such cases the ten percent fines value should be determined instead.

Apparatus :

A 15-cm diameter open-ended steel cylinder, with plunger and base-plate, of the general form and

dimensions shown in Fig. ,A straight metal tamping rod, A balance of capacity 3 kg, readable and accurate

to one gram, IS Sieves of sizes 12.5, 10 and 2.36 mm, For measuring the sample, cylindrical metal

measure of sufficient rigidity to retain its form under rough usage and of the following internaldimensions: Diameter 11.5 cm and Height 18.0 cm

Figure :

Procedure :

1. The material for the standard test shall consist of aggregate passing a 12.5 mm IS Sieve and retained

on a 10 mm IS Sieve, and shall be thoroughly separated on these sieves before testing.

2. The aggregate shall be tested in a surface-dry condition. If dried by heating, the period of drying shall


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33not exceed four hours, the temperature shall be 100 to 110C and the aggregate shall be cooled toroom temperature before testing.

3. The appropriate quantity may be found conveniently by filling the cylindrical measure in three layers

of approximately equal depth, each layer being tamped 25 times with the rounded end of the tamping

rod and finally leveled off, using the tamping rod as a straight-edge.

4. The weight of material comprising the test sample shall be determined (Weight A) and the same

weight of sample shall be taken for the repeat test.

5. The apparatus, with the test sample and plunger in position, shall then be placed between the platens

of the testing machine and loaded at as uniform a rate as possible so that the total load is reached in

10 minutes. The total load shall be 400 kN.

6. The load shall be released and the whole of the material removed from the cylinder and sieved on a

2.36 mm IS Sieve for the standard test. The fraction passing the sieve shall be weighed (Weight B).

Calculation :

The ratio of the weight of fines formed to the total sample weight in each test shall be expressed as a

percentage, the result being recorded to the first decimal place:

sievseappropriatthroughpassingfractionofginweightB

sample,dry-surfacesaturatedofginweightA

100ValueCrushingAggregate

A

B


The aggregate crushing value of given sample of coarse aggregate is .. %

The aggregate crushing value should not be more than 45 per cent for aggregate used for concrete other

than for wearing surfaces, and 30 per cent for concrete used for wearing surfaces such a runways, roads

and air field pavements.

Experiment No. : 3(e) Date

Title : Determination of Aggregate Impact Value

Objective : This method of test covers the procedure for determining the aggregate impact

value of coarse aggregate.



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34Theory :The aggregate impact value gives a relative measure of the resistance ofan aggregate to sudden shock or

impact, which in some aggregates differs from its resistance to a slow compressive load.

Apparatus :

An impact testing machine of the general form shown in Fig. 2 and complying with the following:

1. A cylindrical steel cup of internal dimensions: Diameter 102 mm, Depth 50 mm and not less than 6.3

mm thick

2. A metal hammer weighing 13.5 to 14.0 kg, the lower end of which shall be cylindrical in shape,

100.0 mm in diameter and 5 cm long, with a 2 mm chamfer at the lower edge, and case-hardened.

The hammer shall slide freely between vertical guides so arranged that the lower (cylindrical) part of

the hammer is above and concentric with the cup.

3. Means for raising the hammer and allowing it to fall freely between the vertical guides from a height

of 380.0 mm on to the test sample in the cup, and means for adjusting the height of fall within 5 mm.

Sieves-The IS Sieves of sizes 12.5, 10 and 2.36 mm, Tamping Rod, balance of capacity not less than 500

g, Oven etc.

Figure :

Procedure :

1. The test sample shall consist of aggregate the whole of which passes a 12.5 mm IS Sieve and is

retained on a 10 mm IS Sieve. The aggregate comprising the test sample shall be dried in an oven for

a period of four hours at a temperature of 100 to 110C and cooled.

2. The measure shall be filled about one-third full with the aggregate and tamped with 25 strokes of the


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35rounded end of the tamping rod. The net weight of aggregate in the measure shall be determined tothe nearest gram (Weight A)

3. The impact machine shall rest without wedging or packing upon the level plate, block or floor, so

that it is rigid and the hammer guide columns are vertical.

4. The cup shall be fixed firmly in position on the base of the machine and the whole of the test sample

placed in it and compacted by a single tamping of 25 strokes of the tamping rod.

5. The hammer shall be raised until its lower face is 380 mm above the upper surface of the aggregate

in the cup, and allowed to fall freely on to the aggregate. The test sample shall be subjected to a total

of 15 such blows each being delivered at an interval of not less than one second.

6. The crushed aggregate shall then be removed from the cup and the whole of it sieved on the 2.36

mm IS Sieve until no further significant amount passes in one minute. The fraction passing the sieve

shall be weighed to an accuracy of 0.1 g (Weight. B).

7. The fraction retained on the sieve shall also be weighed (Weight C) and, if the total weight (C+B) is

less than the initial weight (Weight A) by more than one gram, the result shall be discarded and a

fresh test made. Two tests shall be made.

Calculation :

The ratio of the weight of fines formed to the total sample weight in each test shall he expressed as a

percentage, the result being recorded to the first decimal place:

SievsISmm2.36throughpassingfractionofginweightB


100ValueImpactAggregate

A

B


The aggregate Impact value of given sample of coarse aggregate is .. %

The aggregate impact value should not be more than 45 per cent for aggregate used for concrete other than

for wearing surfaces, and 30 per cent for concrete used for wearing surfaces such a runways, roads and air

field pavements.

Experiment No. : 3(f) Date

Title : Determination of Aggregate Abrasion Value

Objective : This method of test methods of determining the abrasion value of coarse

aggregate By the use of Los Angeles machine.


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36


Theory :

Abrasive Charge-The abrasive charge shall consist of cast iron spheres or steel spheres approximately 48mm in. diameter and each weight between 390 and 445 g.

The test sample consist of clean aggregate which has been dried in an oven at 105C to 110C and it

should conform to one of the gradings shown in Table 3.22.

Apparatus :

Los Angeles machine - The Los Angeles abrasion testing machine shall consist of a hollow steel cylinder,

closed at both ends, having an inside diameter of 700 mm and an inside length of 500 mm. The cylinder

shall be mounted on stub shafts attached to the ends of the cylinders but not entering it, and shall be


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37mounted in such, a manner that it may be rotated about its axis in a horizontal position. An opening in thecylinder shall be provided for the introduction of the test sample. A removable steel shelf, projecting

radially 88 mm into the cylinder and extending its full length, shall be mounted along one element of the

interior surface of the cylinder. The shelf shall be of such thickness and so mounted, by bolts or other

approved means, as to be firm and rigid. The 1.70 mm IS Sieve.

Figure :

Procedure :

1. The test sample shall consist of clean aggregate which has been dried in an oven at 105 to 110C to

substantially constant weight and shall conform to one of the gradings shown in Table 3.22. The

grading or gradings used shall be those most nearly representing the aggregate furnished for the

work.

2. The test sample and the abrasive charge shall be placed in the Los Angeles abrasion testing machine

and the machine rotated at a speed of 20 to 33 rev/min. For gradings A, B, C and D, the machine

shall be rotated for 500 revolutions; for gradings E, F and G, it shall be rotated for 1 000 revolutions.

3. The machine shall be so driven and so counter-balanced as to maintain a substantially uniform

peripheral speed. If an angle is used as the shelf, the machine shall be rotated in such a direction that

the charge is caught on the outside surface of the angle.

4. At the completion of the test, the material shall be discharged from the machine and a preliminary

separation of the sample made on a sieve coarser than the l.70 mm IS Sieve.

5. The material coarser than the 1.70 mm IS Sieve shall be washed dried in an oven at 105 to 110C to a

substantially constant weight, and accurately weighed to the nearest gram.

Calculation :

The difference between the original weight and the final weight of the test sample is expressed as a

percentage of the original weight of the test sample. This value is reported as the percentage of wear.


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38

SievsISmm1.70throughpassingfractionofginweightB


100ValueAbrassionAggregate

A

B


The aggregate Abrasion Value of given sample of coarse aggregate is .. %

The percentage of wear should not be more than 16 per cent for concrete aggregates.


Title : Concrete Mix Design by ACI Committee 211.1 of 1991 Method

Objective : To determine the concrete mix proportion by American Concrete Institute

Method of Mix Design (ACI Committee 211.1 of 1991) Method.

Reference : ACI Committee 211.1 of 1991


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39Theory :Data to be collected :

(i) Fineness modulus of selected F.A.

(ii) Unit weight of dry rodded coarse aggregate.

(iii) Sp. gravity of coarse and fine aggregates in SSD condition

(iv) Absorption characteristics of both coarse and fine aggregates.

(v) Specific gravity of cement.

Apparatus :

(1) Concrete mixer, (2) Balance, (3) Molds (or forms) for casting of the test specimens for future testing.

Procedure :

1. From the minimum strength specified, estimate the average design strength either by using standard

deviation or by using coefficient of variation.

ksffm minstrength,meanThe

2. Find the water/cement ratio from the strength point of view from Table 11.5. Find also the water/

cement ratio from durability point of view from Table 11.6. Adopt lower value out of strength

consideration and durability consideration.


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40

3. Decide maximum size of aggregate to be used. Generally for RCC work 20 mm and prestressed

concrete 10 mm size are used.

4. Decide workability in terms of slump for the type of job in hand. General guidance can be taken from

table 11.7.

5. The total water in kg/m3 of concrete is read from table 11.8 entering the table with the selected

slump and selected maximum size of aggregate. Table 11.8 also gives the approximate amount of

accidentally entrapped air in non-air-entrained concrete.


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41

6. Cement content is computed by dividing the total water content by the water/cement ratio.

2StepfromRatioCementWater /

/inWaterTotalcontentcementrequiredThe

3mkg

7. From table 11.4 the bulk volume of dry rodded coarse aggregate per unit volume of concrete is

selected, for the particular maximum size of coarse aggregate and fineness modulus of fine

aggregate.

8. The weight of C.A. per cubic meter of concrete is calculated by multiplying the bulk volume with

bulk density.


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42C.A.ofDensityBulk11.4)TAble(From

ConcreteofVolumePer UnitC.A.ofVolumeBulkDry/inC.A.ofweighttheTherefore 3

mkg

9. From Table 11.9, the first estimate of density of fresh concrete for 20 mm maximum size of

aggregate and for non-air-entrained concrete

10.The solid volume of coarse aggregate in one cubic meter of concrete is calculated by knowing the

specific gravity of C.A.

11.Similarly the solid volume of cement, water and volume of air is calculated in one cubic meter of

concrete.

12.The solid volume of sand is computed by subtracting from the total volume of concrete the solid

volume of cement, coarse aggregate, water and entrapped air.

Item Ingredients Weight Absolute volume

1 Cement From Step 633 1010

CementofgravitySp.

CementofWeight

2 Water From Step 533 1010

WaterofgravitySp.

WaterofWeight

3 Coarse Aggregate From Step 833 1010

C.A.ofgravitySp.

C.A.ofWeight

4 Air ---36 1010

100

VoidsAirof%

Total absolute volume =

13.Wight of fine aggregate is calculated by multiplying the solid volume of fine aggregate by specific

gravity of F.A.

3

10Volume)AbsoluteTotal-(1000F.A.ofvolumeAbsolute

F.A.ofGravitySp.F.A.ofvolumeAabsoluteF.A.ofWeight


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43Result/ Conclusion :Final Mix Proportion by American Concrete Institute Method of Mix Design (ACI Committee 211.1 of

1991) Method

Ingredients CementFine

Aggregate

Coarse

AggregateWater

Chemical

Quantity3/ mkg

300.00 870.95 1423.90 135.00 NM

Ratio 1.00 2.90 4.75 0.45 NM


Title : Concrete Mix Design by DOE Method of Concrete Mix Design

Objective : To determine the concrete mix proportion by DOE Method of Concrete Mix

Design Method.

Reference : DOE Method of Concrete Mix Design Method.

Theory :

The DOE method was first published in 1975 and then revised in 1988. While Road Note No 4 or Grading

Curve Method was specifically developed for concrete pavements, the DOE method is applicable to

concrete for most purposes, including roads. The method can be used for concrete containing fly ash (in

U.K. it is called pulverized fuel ash, PFA) or GGBFS. Since DOE method presently is the standard British

method of concrete mix design, the procedure involved in this method is described instead of out dated

Road Note No 4 method.

Data to be collected :

(i) Fineness modulus of selected F.A.

(ii) Unit weight of dry rodded coarse aggregate.

(iii) Sp. gravity of coarse and fine aggregates in SSD condition

(iv) Absorption characteristics of both coarse and fine aggregates.

(v) Specific gravity of cement.

Apparatus :


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44(1) Concrete mixer, (2) Balance, (3) Molds (or forms) for casting of the test specimens for future testing.

Procedure :

1. Find the target mean strength from the specified characteristic strength Target mean strength =

specified characteristic strength + Standard deviation x risk factor. (Risk factor is on the assumptionthat 5 percent of results are allowed to fall less than the specified characteristic strength).

ksffm minstrength,meanThe

2. Step 2: Calculate the water/cement ratio. This is done in a rather round about method, using Table

11.11 and Fig. 11.3.

3.

Next decide water content for the required workability, expressed in terms of slump or Vebe time,

taking into consideration the size of aggregate and its type from Table 11.12.


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45

4. Find the cement content knowing the water/cement ratio and water content. Cement content is

calculated simply dividing the water content by W/C ratio.


/inWaterTotalcontentcementrequiredThe3mkg

The cement content so calculated should be compared with the minimum cement content specified

from the durability consideration as given in Table 9.20 or Table 9.21 and higher of the two should

be adopted. Sometime maximum cement content is also specified. The calculated cement content

must be less than the specified maximum cement content.


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46

5. Next find out the total aggregate content. This requires an estimate of the wet density of the fully

compacted concrete. This can be found out from Fig. 11.4 for approximate water content and specific

gravity of aggregate. The aggregate content is obtained by subtracting the weight of cement and

water content from weight of fresh concrete.


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473)StepfromWaterofWeight4StepfromCement

of(Weight-Fig)(fromConcreteofdensitywetThe/inAggregateTotalofweightThe 3

mkg

6. Then, proportion of fine aggregate is determined in the total aggregate using Fig. 11.5. Fig. 11.5(a) is

for 10 mm size, 11.5(b) is for 20 mm size and Fig. 11.5(c) is for 40 mm size coarse aggregate. The

parameters involved in Fig. 11.5 are maximum size of coarse aggregate, the level of workability, the

water/cement ratio, and the percentage of fines passing 600 sieves. Once the proportion of F.A. is

obtained, multiplying by the weight of total aggregate gives the weight of fine aggregate. Then the

weight of the C.A. can be found out. Course aggregate can be further divided into different fractions

depending on the shape of aggregate. As a general guidance the figures given in Table 11.14 can be

used.


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48

Wight of fine aggregate is calculated by multiplying the solid volume of fine aggregate by specific


49/72



49gravity of F.A.310Volume)AbsoluteTotal-(1000F.A.ofvolumeAbsolute

F.A.ofGravitySp.F.A.ofvolumeAabsoluteF.A.ofWeight

Result/ Conclusion :

Final Mix Proportion by DOE Method of Concrete Mix Design Method.


Aggregate

Coarse

AggregateWater

Chemical

Quantity3/ mkg

300.00 870.95 1423.90 135.00 NM

Ratio 1.00 2.90 4.75 0.45 NM


Title : Concrete Mix Design by Indian standard method IS 10262-2009

Objective : To determine the concrete mix proportion by Indian standard Recommended

method IS 10262-2009

Reference : IS 10262-2009, IS 456 -2000

Theory :

Data to be collected :

1. Characteristic compressive strength ( that is, below which only a specified proportion of test results

are allowed to fall ) of concrete at 28 days (fck)

2. Degree of workability desired

3. Limitations on the water-cement ratio and the minimum cement content to ensure adequate durability

4. Type and maximum size of aggregate to be used

5. Standard deviation (S) of compressive strength of concrete.

Apparatus :

(1) Concrete mixer, (2) Balance, (3) Molds (or forms) for casting of the test specimens for future testing.

Procedure :


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501. According to IS: 4562000 and IS: 134380, the characteristic strength is defined as that valuebelow which not more than 5 per cent results are expected to fall, in which case the Target mean

strength for mix design

deviation.standardtheisSdays.28atstrengthecompressivsticcharacteriwhere

65.1Strength,MeanTargetThe

ck

ckck

f

Sff

Table No. 2 Assumed Standard Deviation

Sr. No.Nominal Maximum Size of

Aggregate

Assumed Standard Deviation

N/mm2

1 M 103.50

2 M 15

3 M 204.004 M 25

5 M 30

5.00

6 M 35

7 M 40

8 M 45

9 M 50

10 M 50

2.

Selection of Water / Content Ratio consider from the specified table (Table-5) of IS: 456 for desired

exposure condition as preliminary w/c ratio that has to be further checked for limiting value ensuring

durability.

3. Calculation of Water Content. IS: 10262-2009 allows use of water reducers/ super plasticizers and

also specifies the alteration in water content accordingly. Further water adjustment was specified in


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51terms of variation of compaction factor in the older version whereas the same has been remolded interms of slump variation (+3% for every 25mm slump over 50mm) in the revised one.

Table No. 2 Maximum Water Content per Cubic Meter of Concrete for Nominal

Maximum Size of Aggregate

Sr. No.Nominal Maximum Size of

Aggregate

Maximum Water Content3/ mkg

1 10 208

2 20 189

3 40 165

4. Calculation of Cement Content. The cement content per unit volume of concrete may be calculated

from free water-cement ratio and the quantity of water per unit volume of concrete (cement by mass

= Water content/Water cement ratio).


/inWaterTotalContentCementrequiredThe

3mkg

The cement content so calculated shall be checked against the minimum cement content for the

requirement of durability and the greater of the two values to be adopted.

5. Calculation of Coarse Aggregate Proportion: For the desired workability, the quantity of mixing

water per unit volume of concrete and the ratio of coarse aggregate to total aggregate by absolute

volume are to be estimated from Tables 3

Table No. 3 Volume of Coarse Aggregate per Unit Volume of Total Aggregate for

Different Zones of Fine Aggregate

Sr. No.Nominal Size

of AggregateZone IV Zone III Zone II Zone I

1 10 0.50 0.48 0.46 0.442 20 0.66 0.64 0.62 0.60

3 40 0.75 0.73 0.71 0.69

6. Calculation of aggregate content. Aggregate content can be determined from the following equations

ca

fa

aa

ca

a

C

S

SC

Pf

S

C

PS

CWV

1

1

1


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52

ly.respectiveaggregate

eand coarsaggregatee dry fineed, surfacof saturatgravitiesSpecific, SS

ively andte respectof concre) per mand CA (kgses of FATotal masCf

lumebsolute voegate by atotal aggrregate toCoarse aggRatio ofP

cementgravity ofSpecificS

teof concreper mement (kg)Mass of cC

teof concreper mater (kg)Mass of wW

air,entrappedvolume of

us the)volume (mto grossh is equalrete, whicfresh concvolume ofabsoluteV

cafa

aa,

c

min

where

3

3

3

3

7. Combination of Different Coarse Aggregate Fractions: The coarse aggregate used shall conform to IS

3831970. Coarse aggregate of different sizes may be combined in suitable proportions so as result

in an overall grading conforming to Table 2 of IS 383 1970 for nominal maximum size of

aggregate.

Result/ Conclusion :

Final Mix Proportion by American Concrete Institute Method of Mix Design (ACI Committee 211.1 of

1991) Method


Aggregate

Coarse

AggregateWater

Chemical

Quantity3/ mkg

300.00 870.95 1423.90 135.00 NM

Ratio 1.00 2.90 4.75 0.45 NM


53/72



53


Title : Making and Curing Concrete Test Specimens in the Laboratory

Objective : This practice cover procedures for making and curing test specimens of

concrete in the laboratory under accurate control of materials and test conditions

using concrete that can be consolidated by rodding or vibration .

Reference : IS 456 : 2000, SP : 23-1982,IS: 1199-1959

Procedure :

Weighing:

1. The quantities of cement, each size of aggregate, and water for each batch shall be determined by

weight, to an accuracy of 0.1 percent of the total weight of the batch

Procedure for mixing Concrete :

Machine Mixing:

1. Put the coarse aggregate in the mixer, add some of the mixing water and the solution of admixture,

when required, [add with water].

2. Start the mixer, then add the fine aggregate, cement and water with the mixer running .If it is

impractical to add the fine aggregate, cement and water with the mixer is running, these components

may be added to the stopped mixer after permitting it to turn a few revolutions following charging

with coarse aggregate and some of the water.

3. Mix the concrete, after all integrates are in the mixer, for 3 minutes followed by 3 minutes rest,

following by 2-minutes final mixing.

Hand Mixing:-

1. The cement and fine aggregate shall be mixed dry until the mixture is thoroughly blended and is

uniform in colour,

2. The coarse aggregate shall then be added and mixed with the cement and fine aggregate until the

coarse aggregate is uniformly distributed throughout the batch, and

3. The water shall then be added and the entire batch mixed until the concrete appears to be

homogeneous and has the desired consistency.

4.

If repeated mixing is necessary, because of the addition of water in increments while adjusting theconsistency, the batch shall be discarded and a fresh batch made without interrupting the mixing to


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54make trial consistency tests.Making Specimens:

Place of Molding:

1. Mold specimens as near as practicable to the place where they are to be stored during the first 24

hours.

2. Place molds on a rigid surface free from vibration and other disturbances

3. If it is not practicable to mold the specimens where they will be stored, move them to the place of

storage immediately after being struck off.

Placing:

1. Place the concrete in the molds using a scoop, blunted trowel, or shovel. Select each scoopful,

trowelful, or shovelful of concrete from the mixing pan to ensure that it is representative of the batch.

2. It may be necessary to remix the concrete in the mixing pan with a shovel to prevent segregation

during the molding of specimens.

3. Move the scoop or trowel a round the top edge of the mold as the concrete is discharged in order to

ensure symmetrical distribution of the concrete and for minimize segregation of coarse aggregate

within the mold.

4. Further distribute the concrete by use of a tamping rod prior to the start of consolidation.

Methods of consolidation :

Preparation of satisfactory specimens requires different methods of consolidation. The methods of

consolidation are: a) Rodding, b) Internal vibration, c) External vibration.

Rodding:

1. Place the concrete in the mold in the required number of layers of approximately equal volume .Rod

each layer with the rounded end of the rod using the number of strokes.

2. Rod the bottom layer throughout its depth. Distribute the strokes uniformly over the cross-section of

the mold and for each upper layer allow the rod to penetrate about 12mm into the underlying layer

when the depth of the layer is less than 100mm and about (25mm) when the depth is (100mm) or

more.

3. After each layer is rodded, tap the outside of the mold lightly 10-15 times with the mallet to close

any holes left by rodding.

Vibration:

1. The duration of vibration required will depend upon the workability of the concrete and the

effectiveness of the vibrator. Continue vibration only long enough to achieve proper consolidation of

the concrete.

2.

Fill the molds and vibrate in the required number of approximately equal layers. Place all the

concrete for each layer in the mold before starting vibration of that layer.


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553. Add the final layer, so as to avoid over filling by more than (6 mm). Then finish the surface.Finishing:

After consolidation, strike off the surface of the concrete and float or trowel it with a wood or

magnesium float.

Curing:

1. The test specimens shall be stored in a place, free from vibration, in moist air of at least 90 percent

relative humidity and at a temperature of 27 2C for 24 hours hour from the time of addition

of water to the dry ingredients.

2. After this period, the specimens shall be marked and removed from the moulds and, unless required

for test within 24 hours, immediately submerged in clean, fresh water or saturated lime solution and

kept there until taken out just prior to test.

3. The water or solution in which the specimens are submerged shall be renewed every seven days and

shall be maintained at a temperature of 27 2C. The specimens shall not be allowed to become dry

at any time until they have been tested.


Title : Determination Workability of Fresh Concrete By Slump Cone

Test

Objective : To determine the relative consistency of freshly mixed concrete by the use of

Slump Test.

Reference : IS: 7320-1974, IS: 1199-1959, SP : 23-1982

Theory :

The word workability or workable concrete signifies much wider and deeper meaning than the other

terminology consistency often used loosely for workability. Consistency is a general term to indicate the

degree of fluidity or the degree of mobility.

The factors helping concrete to have more lubricating effect to reduce internal friction for helping easy

compaction are given below:

(a) Water Content (b) Mix Proportions (c) Size of Aggregates (d) Shape of Aggregates (e) Surface Texture

of Aggregate (f) Grading of Aggregate (g) Use of Admixtures.

Measurement of Workability

The following tests are commonly employed to measure workability.


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56(a) Slump Test (b) Compacting Factor Test (c) Flow Test (d) Kelly Ball Test (e) Vee Bee ConsistometerTest.

Slump Test: Slump test is the most commonly used method of measuring consistency of concrete which

can be employed either in laboratory or at site of work. It is not a suitable method for very wet or very dry

concrete. It does not measure all factors contributing to workability, nor is it always

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