Concrete lab manual - Polytechnics

Lab manual of Government Polytechnic College Manjeri

1. CONCRETE LAB RECORD







Name :
Register Number :
Period :




Department of Civil Engineering
Government Polytechnic College Manjeri
Malappuram, India – 676123

2. LIST OF EXPERIMENTS
No Name of Experiment Date Marks Sign
GENERAL INSTRUCTIONS IN CONCRETE LAB
TESTS ON CEMENT
1 FINENESS OF CEMENT BY DRY SIEVING
2 SPECIFIC GRAVITY OF CEMENT
3 CONSISTENCY TEST ON CEMENT
4 INITIAL & FINAL SETTING TIME OF CEMENT
5 SOUNDNESS TEST ON CEMENT
TESTS ON AGGREGATES
6 BULKING OF SAND
7 SIEVE ANALYSIS OF FINE AGGREGATES
8 SIEVE ANALYSIS OF COARSE AGGREGATES
9 FLAKINESS INDEX AND ELONGATION INDEX
10 PHYSICAL PROPERTIES OF FINE AGGREGATE
11 PHYSICAL PROPERTIES OF COARSE AGGREGATE
TESTS ON CONCRETE
11 WORKABILITY OF CONCRETE BY SLUMP TEST
12 COMPACTION FACTOR TEST
13 COMPRESSIVE STRENGTH OF CONCRETE
14 CONCRETE MIX DESIGN – IS METHOD
Average marks of all experiments

All the ……… experiments are verified.


Lecturer in charge:

3. Exp No: 1 Date:
FINENESS OF CEMENT BY DRY SIEVING
AIM:

To determine the fineness of given sample of cement by dry sieving

APPARATUS USED:

1. Weighing balance (Least Count = 1 g)
2. IS Sieve 90 micron
3. Brush, Tray and Trowel

THEORY:

Cement is in form of powder, which is obtained by grinding various raw
materials. The grinding produces finer particles of cement. The degree to which
the cement is grinded into smaller and smaller particles is called fineness of
cement. The degree of fineness of cement is the measure of the mean size of the
grains in it.
During mixing of cement with water, chemical reaction take place
between them, called as hydration. The strength of cement or mortar develops
with hydration. More the rate of hydration, faster is the development of
strength. This is because finer cement offers greater surface area of particles for
hydration. At the same time the rate of development of heat due to hydration
also increases.
Fineness is defined as the surface area of cement present per unit weight
of cement, which implies that more fineness means more particles in unit
weight.

4. TEST ON CEMENTS
1. Field testing
a. Open the bag and take a good look at the cement - no visible
lumps.
b. Colour = Greenish grey
c. Should get a cool feeling when thrusted
d. When we throw the cement on a bucket full of water, before it
sinks the particle should flow
2. Laboratory testing
a. Fineness test
b. Specific gravity
c. Consistency
d. Setting time
e. Soundness
f. Compressive strength
g. Tensile strength

PROCEDURE:
1. Break down any air-set lumps in the cement sample with fingers.
2. Weigh accurately 100 grams of cement and place it on a standard IS Sieve
of 90 micron
3. Continuously sieve the sample for 15 minutes
4. Weigh the residue left after 15 minutes of sieving. This completes the test.

5. RESULT:



DISCUSSION:

6. Exp No: 2 Date:
SPECIFIC GRAVITY OF CEMENT

AIM:

To determine the specific gravity of given sample of cement by specific gravity
bottle method.

APPARATUS USED:

1. Specific gravity bottle 50 ml
2. Weighing balance

THEORY:

Specific gravity of the cement is the ratio of the weight of a given volume of the
cement and weight of an equal volume of water. The specific gravity of
Portland cement is generally about 3.15. Cement will react with water. So to
determine the specific gravity of cement, kerosene which does not react with
cement is used.
Note:
Specific gravity has no unit

7. PROCEDURE:

1. Clean and dry the density bottle
a. Wash the bottle with water and allow it to drain.
b. Wash it with alcohol and drain it to remove water.
c. Wash it with ether, to remove alcohol and drain ether.
2. Weigh empty specific gravity bottle with its stopper (w1)
3. Fill a sample of cement up to one fourth of the bottle and weigh it (w2)
4. Pour kerosene over the cement to fill the bottle and find the total weight
(w3). Mix thoroughly with glass rod to remove entrapped air.
5. Clean the bottle thoroughly using kerosene and fill the bottle with
kerosene and weigh it (w4)
6. Finally clean the bottle with water. Fill it with water and weigh it (w5)
7. Find specific gravity of cement using the equation

Specific gravity of the cement , Gc =
w2−w1
(�4−�1)−(�3−�2)
x Gk

Where
Gk =
weight of kerosene
��??????�ℎ?????? ??????� �????????????�??????
=
w4−w1
�5−�1


8. Take average of values obtained and report the value.

8. RESULT:



DISCUSSION:

9. Exp No: 3 Date:
CONSISTENCY TEST ON CEMENT
AIM:

To determine the percentage of water for normal or standard consistency

THEORY:
A certain minimum quantity of water is required to be mixed with cement
so as to complete chemical reaction between water and cement, less water than
this quantity would not complete chemical reaction thus resulting in reduction
of strength and more water would increase water cement ratio and so would
reduce its strength. So correct proportion of water to cement is required to be
added to achieve proper strength while using cement in structures. This can be
found out by knowing standard or normal consistency of cement paste.
For finding out the initial setting time, final setting time and soundness of
cement, this standard parameter is used.
The standard consistency of a cement paste is defined as that
consistency (degree of wetness) which will permit the vicat plunger to
penetrate to a point 5 to 7 mm from the bottom of the vicat mould when the
cement paste is tested within 3 – 5 minutes after it is mixed with water.
Since different batches of cement differ in fineness, pastes with same water
content may differ in consistency when first mixed. For this reason the
consistency of the paste is standardized by varying the water content until the
paste has a given resistance to penetration. It is expressed as amount of water as
a percentage [by weight] of dry cement.

10. Gauging time: It is the period observed from the time water is added to cement
for making cement paste till commencing the filling of mould of vicat
apparatus, in this test.
APPARATUS USED:

1. Vicat apparatus with 10 mm dia plunger
2. Vicat mould
3. Non porous plate
4. Weighing balance
5. Measuring jar
6. Trowel

PROCEDURE:

1. Take 400 g of cement and place it in the tray
2. Mix about 25 % water by weight of dry cement thoroughly to get a
cement paste. i.e., 100 gm [100 ml]. Total time taken to obtain
thoroughly mixed water cement paste (Gauging time) should not be more
than 3 to 5 minutes.
3. Calculate percentage of water (P) by weight of dry cement required to
prepare cement paste of standard consistency by following formula
P =
??????
??????
x 100

Where,
W = Quantity of water added
C = Quantity of cement used

11. 4. Fill the vicat mould, resting upon a glass plate, with this cement paste.
5. After filling the mould completely, smoothen the surface of the
paste, making it level with top of the mould
6. Place the whole assembly (i.e. mould + cement paste + glass plate) under
the rod bearing plunger.
7. Lower the plunger gently so as to touch the surface of the test block and
quickly release the plunger allowing it to sink into the paste.
8. Measure the depth of penetration and record it.
9. Prepare trial pastes with varying percentages of water content, increasing
water percentage by 1% each time, until the depth of penetration
becomes 33 to 35 mm [or 5 – 7 mm from bottom of the mould]

12. RESULT:



DISCUSSION:

13. Exp No: 4 Date:
INITIAL AND FINAL SETTING TIME OF CEMENT

AIM:
To determine the initial and final setting time of the cement
APPARATUS USED:
1. Vicat apparatus
2. Weighing balance
3. Measuring jar
4. Trowel

THEORY:
SETTING TIME
Setting means becoming firmer and harder, changing from semi-liquid state to
plastic state and from plastic state to solid state. Mortar or concrete when mixed
is in semi liquid state. The chemical action between cement and water starts,
and the mixture goes into plastic state. Concrete or mortar must be transported,
placed and compacted when in plastic state. After some time [which is the final
setting time] the plasticity is lost and the mortar or concrete cannot be placed or
deposited
INITIAL SETTING TIME:
The time period elapsing between the time water is added to the cement and the
time the needle fails to pierce the test block by 5 ± 0.5 mm measured from the
bottom of the mould is the initial setting time.

14. FINAL SETTING TIME:
The period elapsing between the time water is added to the cement and the time
the needle makes an impression on the surface of the test block while the
attachment fails to do so is the final setting time.
PROCEDURE:
1. Prepare a paste of 300 grams of cement
2. Prepare a neat cement paste by adding 0.85 times the water required to
give a paste of standard consistency
3. Start a stop watch at the instant when water is added to the cement.
4. After completely filling the mould, it should be shaken slightly to expel
the air. Smooth off the surface of the paste making it level with the top of
the mould.

INITIAL SETTING TIME:

5. Lower the needle gently in order to make contact with the surface of the
cement paste and release quickly
6. Repeat the procedure till the needle fails to pierce the test block to a point
5.0 ± 0.5mm measured from the bottom of the mould.

FINAL SETTING TIME:

7. Replace the above needle by the one with an annular attachment.
8. The cement should be considered as finally set when, upon applying the
needle gently to the surface of the test block, the needle makes an
impression

15. RESULT:



DISCUSSION:

16. Exp No: 5 Date:
SOUNDNESS TEST ON CEMENT

AIM:

To determine the soundness of given cement
APPARATUS USED:
1. Le chatelier apparatus
2. Weighing balance

THEORY:

Soundness Test on Cement is carried out to detect the presence of
uncombined lime in cement. This test is performed with the help of Le Chatelier
apparatus. It consists of a brass mould of diameter 30 mm and height 30 mm.
There is a split in mould and it does not exceed 0.50 mm. On either side of split,
there are two indicators with pointed ends. The thickness of mould cylinder is
0.50 mm.

PROCEDURE:

1. Take a sample of 100 grams.
2. Add 0.78 times water required for standard consistency.
3. Make a paste.
4. Fill the mould of Le Chatelier apparatus with cement paste,
keeping the mould on a glass plate, keep the edges of the mould
gently together.

17. 5. Cover the mould with another plate of glass sheet. A small weight
is placed above it. Then immediately submerge the whole assembly
in water at a temperature of 27
0
C ± 2
0
C. Keep it under water for 24
hours.
6. After 24 hours, the mould is taken out of water and the distance
(d1) between the two indicators is measured. Replace the assembly
in the same water.
7. The water is heated and brought to a boiling point of 25 to 30
minutes. Then keep the water boiling for 3 hrs.
8. Remove the mould from the water, allow it to cool and measure the
distance between the indicator points (d2).

18. RESULT:
Familiarized with the procedure for soundness test.

DISCUSSION:

19. Exp No: Date:
BULKING OF SAND
AIM:

To determine the moisture content at which the bulking of sand occurs

APPARATUS USED:
1. Weighing balance
2. Measuring jar
3. Mixing pan, trowel, etc…

20. THEORY:
The volume increase of fine aggregate due to presence of moisture content is
known as bulking. A moisture film around particles which cause increase in
volume. There is no bulking when the sand is dry or when it is fully saturated
with water. Fine sand bulks more than coarse sand. Coarse aggregate does not
bulk. In volumetric batching, if sand is moist, it is necessary to increase the
amount of sand to be added in each batch, to compensate for bulking. ie,
increase in volume of sand which occurs if the sand is moist.
PRINCIPLE:

The principle used in bulking of sand is
Percentage of bulking of sand =
�− �??????
�??????

where, v = volume of bulked sand
va = Actual volume of sand

PROCEDURE:

1. Take 200 ml of sand in a measuring jar and take the weight of sand
2. Add water in 1 % by weight of sand and mix thoroughly
3. Fill the sand in the measuring jar and note the increase in volume
4. Then repeat the experiment for 2 %, 3%, 4 %, 5 %, 6 %, 7 % 8 %, 9%, 10
%, etc.. until the volume starts decreasing. This is the original volume of
sand.
5. Plot the graph by taking percentage of increase in volume and percentage
bulking

21. OBSERVATIONS AND CALCULATIONS

% of water
added
Volume of
water added (ml)
Volume of
bulked sand (ml)
% bulking =

22. RESULT:

The maximum bulking of sand takes place at a moisture content of ……..% and
maximum percentage bulking is obtained as ……….%

DISCUSSION:

Bulking of sand increases with increase in moisture content, up to a certain
limit. Beyond that further increase in moisture content decrease the volume of
bulked sand.

23. Exp No: Date:
SIEVE ANALYSIS OF FINE AGGREGATE

AIM:

To determine the particle size distribution of fine aggregates by conducting dry
sieve analysis and to identify to which the zone belongs to.

APPARATUS USED:
3. Weighing balance

24. 4. IS Sieves of size 10 mm, 4.75 mm, 2.36 mm, 1.18 mm, 600 micron,
300 micron, 150 micron, and pan

THEORY:

Sieve analysis helps to determine the particle size distribution of the coarse and
fine aggregates. Particle size distribution analysis (PSD) means grading or
separation of fine aggregates (sand) into particles of different sizes. This is done
by sieving the aggregates as per IS: 2386 (Part I) – 1963. In this we use
different sieves as standardized by the IS code and then pass aggregates through
them and thus collect different sized particles left over different sieves.

The aggregate which passes through IS 4.75 mm sieve is fine aggregate and that
which retained on it is coarse aggregate. A sample may be well graded, poorly
graded or uniformly graded. The term D10 (Effective size) represents sieve
opening such that 10 % of the particles are finer than this size. Similarly D30 and
D60 can also be obtained from the graph.


Uniformity coefficient, Cu =
D60
D10


Fineness modulus is a term representing the fineness or coarseness of the
material.

PROCEDURE:

1. Take 1 kg of fine aggregate (sand)
2. Weight of each sieve is noted

25. 3. The sample is sieved by using a set of IS Sieves arranged in such a way
that largest sieve on top (i.e., 10 mm to 150 micron). Sieving is done by
shaking the sieve using hands.
4. On completion of sieving, the material on each sieve is weighed.
5. Cumulative weight passing through each sieve is calculated as a
percentage of the total sample weight.
6. Fineness modulus is obtained by adding cumulative percentage of
aggregates retained on each sieve and dividing the sum by 100.










OBSERVATIONS AND CALCULATIONS:

Sieve
size
(mm)
Mass of
sieve
(g)
Mass of
sieve and
aggregate
(g)
Mass
retained
(g)
Percentage of mass
retained on each
sieve
(%)
Cumulative
percentage
weight
retained
(%)
% finer
A B C = B - A D =
??????
??????��??????� ??????����� �� �??????�� ��
??????��� ΣD 100 - ΣD
4.75

2.36

26. Fineness modulus =
cumulative % wt retained
100









1.18

0.600

0.300

0.150

Pan

IS Sieve
size
(mm)
Percentage passing by weight for Grading zone
1 2 3 4
10 100 100 100 100
4.75 90 - 100 90 - 100 90 - 100 95 - 100
2.36 60 - 95 75 – 100 85 - 100 95 - 100
1.18 30 – 70 55 – 90 75 – 100 90 - 100
0.600 15 - 34 35 – 59 60 – 79 80 - 100

27. RESULT:
0.300 5 - 20 8 - 30 12 - 40 15 - 50
0.150 0 - 10 0 - 10 0 - 10 0 - 15
Fineness
modulus
4.0 – 2.41 3.37 – 2.10 2.78 – 1.71 2.25 – 1.35

28. The semi log graph for sieve analysis is plotted.
Effective size, D10 = ……….
Uniformity coefficient, Cu = ……….
Fineness modulus = .………
Grading zone = ……….




DISCUSSION:

Sand classification Fineness modulus
Very fine 0.5 – 2.20
Fine 2.20 – 2.60
Medium 2.60 – 2.90
Coarse 2.90 – 3.5

Fineness modulus is obtained as …. . Hence the given sample is fine / medium /
coarse






Exp No: Date:
SIEVE ANALYSIS OF COARSE AGGREGATE

29. AIM:

To determine the particle size distribution of coarse aggregates by conducting
dry sieve analysis and to identify to which the zone belongs to.

APPARATUS USED:

1. Weighing balance
2. IS Sieves of size 80 mm, 40 mm, 20 mm, 10 mm, 600 micron, 300
micron, 150 micron, and pan

THEORY:

The aggregate which passes through IS 4.75 mm sieve is fine aggregate and that
which retained on it is coarse aggregate. A sample may be well graded, poorly
graded or uniformly graded. The term D10 (Effective size) represents sieve
opening such that 10 % of the particles are finer than this size. Similarly D30 and
D60 can also be obtained from the graph.

Uniformity coefficient, Cu =
D60
D10


Fineness modulus is a term representing the fineness or coarseness of the
material.

PROCEDURE:

1. Take 5 kg of coarse aggregate

30. 2. Weight of each sieve is noted
3. The sample is sieved by using a set of IS Sieves arranged in such a
way that largest sieve on top (i.e., 10 mm to 150 micron). Sieving is
done by shaking the sieve using hands.
4. On completion of sieving, the material on each sieve is weighed.
5. Cumulative weight passing through each sieve is calculated as a
percentage of the total sample weight.
6. Fineness modulus is obtained by adding cumulative percentage of
aggregates retained on each sieve and dividing the sum by 100.
7.
OBSERVATIONS AND CALCULATIONS:

Sieve
size
(mm)
Mass of
sieve
(g)
Mass of
sieve and
aggregate
(g)
Mass
retained
(g)
Percentage of mass
retained on each sieve
(%)
Cumulative
percent
retained
(%)
% finer
A B C = B - A D =
??????
??????��??????� ??????����� �� �??????����
??????��� ΣD 100 - ΣD
80

40

20

10

6.3

4.75

Total


Fineness modulus =
cumulative % wt retained
100

31. RESULT:

Semi log graph of sieve analysis is plotted.
Effective size, D10 = ……….
Uniformity coefficient, Cu = ……….
Fineness modulus = .………
Grading zone = ……….


DISCUSSION:

Fineness modulus of coarse aggregate is usually more than 5.

32. Set of sieves for coarse aggregates














Exp No: Date:

33. FLAKINESS INDEX AND ELONGATION INDEX

AIM:

To determine the flakiness index and elongation index of given aggregate
sample

APPARATUS USED:

1. Weighing balance
2. Metal thickness guage
3. Metal length guage

THEORY:

The shape of aggregate is an important property since it affects the workability
of concrete. The shape of the aggregate depends on the characteristics of the
parent rock, the type of crusher used, and reduction ratio. From economy point
of view, for given water cement ratio, the cement requirement for round
aggregate will be lesser whereas the angular aggregates consumes greater
cement but results in better interlocking resulting in high strength and
durability. Excessive flaky aggregates make a very poor concrete.

The classification of particles based on shape is as below:

1. Rounded
2. Irregular
3. Angular
4. Flaky
The Flakiness index of aggregate is the percentage by weight of particles in it
whose least dimension (thickness) is less than 3/5 of their mean dimension.

34. The Elongation index of aggregate is the percentage by weight of particles in it
whose greatest dimension (length) is greater than 1.8 times their mean
dimension.
Both flakiness index and elongation index cannot be applied for aggregates
having size less than 6.3 mm. The Indian Standard do not specify limits for
flakiness index and elongation index but generally flakiness index shall not
exceed 40 % and the elongation index shall not exceed 15 %.

PROCEDURE:
1- Secure a representative sample of aggregate.
2- The weight of the sample (W total) for each test shall be not less than that in
the table below:

Aggregate size (mm)
Sample
weight
(kg)
Distance between the
Passing from Retained on
bars of elongation scale Passing from Retained on
63 50 50 -
50 37.5 40 78 mm
37.5 28 15 59
28 20 5 43
20 14 2 30.6
14 10 1 21.6
10 6.3 0.5 14.7


3- Sieve analysis is carried using the above mentioned sieves.
4- The weight of each size is recorded. The sizes of less than 5% of the total
weight are not considered in the test. Let (M2) to be the total weight of the
aggregate excluding the weight of the sizes of less 5% of weight.

35. 5- Try to pass the particles of each size in the direction of its length (max.
dimension) between the corresponding bars of the scale.
6- Separate the particles that do not pass in all sizes and weigh (M3).
7- Try to pass the particle of each size in the corresponding opening of the scale.
8- Separate the particles that pass in all sizes and weigh (M4).

36. OBSERVATION AND CALCULATION:



Elongation Index = M3/M2 × 100
Flakiness Index = M4/M2 × 100

37. RESULT:
1. Elongation Index =
2. Flakiness Index =

DISCUSSION:

38. Exp No: Date:
PHYSICAL PROPERTIES OF FINE AGGREGATE

AIM:
To determine bulk density, void ratio, porosity and specific gravity of fine
aggregate.

APPARATUS USED:
1. Cylindrical containers having capacities 3, 15 and 30 litres.
2. 16 mm dia. tamping rod 60 cm long.
3. Weighing balance etc.
THEORY:
Bulk density is the weight of a unit volume of aggregate. In estimating
quantities of materials and in mix compaction, when batching is done on a
volumetric basis, it is necessary to known the conditions under which the
aggregate volume is measured viz a. Loose or compact b. Dry, damp or
incinerated. For general information and for comparison of different aggregate,
the standard conditions are dry and compact. For scheduling volumetric batch
quantities, the unit weight in the loose, damp state should be known.
With respect to a mass of aggregate the term voids refers to the space between
the aggregate particles. Numerically this void is the difference between the
gross or overall volume of the aggregate mass and the space occupied by the
aggregate particle alone.
The specific gravity is the ratio of the weight of the substance to the unit weight
of the water. Applied to aggregate the term specific gravity refers to the density
of the individuals’ particles and not to the aggregate mass as a whole.

39. PROCEDURE:
1. The given container has been cleaned weighted (w1)
2. One third of the container has been filled by the given aggregate and the
content has been tamping 25 strokes with tamping rod.
3. The process is repeated for the next two layers.
4. The surplus of aggregate has been struck by using straight edge.
5. The container with the compacted material is weighed (w2)
6. Water has been poured in to the container until the voids are completely
filled. The weight again note down (w3)
7. The container emptied and again filled with loose aggregate and weighed
(w4)
8. Voids are filled with water and again weight is noted (w5)
9. The container is cleaned and again filled with water and weight is note
down (w6)

40. OBSERVATIONS AND CALCULATIONS:
Fine aggregate
loose compact
1. Weight of container (w1)
2. Weight of container + compacted material (w2)
3. Weight of container +compacted material +water
(w3)


4. Weight of container + loose material (w4)
5. Weight of container +loose material +water (w5)


6. Weight of container + water (w6)
7. Bulk density
For loose = (w4-w1)/(w6-w1)
For compact = (w2-w1)/(w6-w1)

8. Void ratio
For loose = (w5-w4)/(w6-w1)-(w5-w4)
For compact = (w3-w2)/(w6-w1)-(w3-w2)

9. Specific gravity
For loose = (w4-w1)/(w6-w1)-(w5-w1)
For compact = (w2-w1)/(w6-w1)-(w3-w2)

10. Porosity
For loose = (w5-w4)/(w6-w1) *100
For compact = (w3-w2)/(w6-w1) *100

41. RESULT:

Physical properties
Fine aggregate
loose compact
Bulk density
Void ratio
porosity
Specific gravity


DISCUSSION:

42. Exp No: Date:
PHYSICAL PROPERTIES OF COARSE AGGREGATE

AIM:
To determine bulk density, void ratio, porosity and specific gravity of coarse
aggregate.

APPARATUS USED:
4. Cylindrical containers having capacities 3, 15 and 30 litres.
5. 16 mm dia tamping rod 60 cm long.
6. Weighing balance etc.
THEORY:
Bulk density is the weight of a unit volume of aggregate. In estimating
quantities of materials and in mix compaction, when batching is done on a
volumetric basis, it is necessary to known the conditions under which the
aggregate volume is measured viz a. Loose or compact b. Dry, damp or
incinerated. For general information and for comparison of different aggregate,
the standard conditions are dry and compact. For scheduling volumetric batch
quantities, the unit weight in the loose, damp state should be known.
With respect to a mass of aggregate the term voids refers to the space between
the aggregate particles. Numerically this void is the difference between the
gross or overall volume of the aggregate mass and the space occupied by the
aggregate particle alone.
The specific gravity is the ratio of the weight of the substance to the unit weight
of the water. Applied to aggregate the term specific gravity refers to the density
of the individuals’ particles and not to the aggregate mass as a whole.

43. PROCEDURE:
10. The given container has been cleaned weighted (w1)
11. One third of the container has been filled by the given aggregate and the
content has been tamping 25 strokes with tamping rod.
12. The process is repeated for the next two layers.
13. The surplus of aggregate has been struck by using straight edge.
14. The container with the compacted material is weighed (w2)
15. Water has been poured in to the container until the voids are completely
filled. The weight again note down (w3)
16. The container emptied and again filled with loose aggregate and weighed
(w4)
17. Voids are filled with water and again weight is noted (w5)
18. The container is cleaned and again filled with water and weight is note
down (w6)

44. OBSERVATIONS AND CALCULATIONS:
coarse aggregate
loose compact
11. Weight of container (w1)
12. Weight of container + compacted material
(w2)

13. Weight of container +compacted material
+water (w3)


14. Weight of container + loose material (w4)
15. Weight of container +loose material +water
(w5)


16. Weight of container + water (w6)
17. Bulk density
For loose = (w4-w1)/(w6-w1)
For compact = (w2-w1)/(w6-w1)

18. Void ratio
For loose = (w5-w4)/(w6-w1)-(w5-w4)
For compact = (w3-w2)/(w6-w1)-(w3-w2)

19. Specific gravity
For loose = (w4-w1)/(w6-w1)-(w5-w1)
For compact = (w2-w1)/(w6-w1)-(w3-w2)

20. Porosity
For loose = (w5-w4)/(w6-w1) *100
For compact = (w3-w2)/(w6-w1) *100

45. RESULT:

Physical properties
coarse aggregate
loose compact
Bulk density
Void ratio
porosity
Specific gravity


DISCUSSION:

46. Exp No: Date:
WORKABILITY OF CONCRETE BY SLUMP TEST

AIM:

To determine the workability of fresh concrete by slump test.

APPARATUS USED:

4. Slump test apparatus (Slump cone, tamping rod)
5. Concrete mixing sheet
6. Trowels
7. Steel rule
8. Weighing balance

THEORY:

It is the simplest test of all the tests of workability. Unsupported fresh
concrete flows to sides and a sinking in height take place. This vertical
settlement is known as slump. In this test fresh concrete is filled into a mould of
specified shape and dimensions, and the settlement or slump is measured when
supporting mould is removed. Slump increases as water content is increased.
For different works, different slump values have been recommended. The slump
is a measure indicating the consistency or workability of cement concrete. It
gives an idea of water content needed for concrete to be used for different
works.

47. A concrete is said to be workable if it can be easily mixed, placed, compacted
and finished. A workable concrete should not show any segregation or bleeding.

Segregation is said to occur when coarse aggregate tries to separate out from
the finer material and bleeding of concrete is said to occur when excess water
comes up at the surface of concrete. This causes small pores through the mass
of concrete and is undesirable.

By this test we can determine the water content to give specified slump value.
In this test water content is varied and in each case slump value is measured till
we arrive at water content giving the required slump value.
True Slump – True slump is the only slump that can be measured in the test.
The measurement is taken between the top of the cone and the top of the
concrete after the cone has been removed as shown in figure-1.
Zero Slump – Zero slump is the indication of very low water-cement ratio,
which results in dry mixes. These type of concrete is generally used for road
construction.
Collapsed Slump – This is an indication that the water-cement ratio is too high,
i.e. concrete mix is too wet or it is a high workability mix, for which a slump
test is not appropriate.
Shear Slump – The shear slump indicates that the result is incomplete, and
concrete to be retested.

48. PROCEDURE:

1. Three mixes are to be prepared with water-cement ratio 0.50, 0.60, 0.70
respectively, and for each mix take 10 kg of coarse aggregate, 5 kg of sand
and 2.5 kg of cement.
2. Clean the internal surface of the mould and apply oil.
3. Place the mould on a smooth horizontal non- porous base plate.
4. Fill the mould with the prepared concrete mix in 4 approximately equal
layers.
5. Tamp each layer with 25 strokes of the rounded end of the tamping rod in a
uniform manner over the cross section of the mould. For the subsequent
layers, the tamping should penetrate into the underlying layer.
6. Remove the excess concrete and level the surface with a trowel.
7. Clean away the mortar or water leaked out between the mould and the base
plate.
8. Raise the mould from the concrete immediately and slowly in vertical
direction.
9. Measure the slump as the difference between the height of the mould and
that of height point of the specimen being tested.

49. OBSERVATIONS AND CALCULATIONS:











Weight of metal taken =
Weight of sand taken =
Weight of cement taken =
Weight of water taken (w/c ratio 0.5) =
Weight of water taken (w/c ratio 0.6) =
Weight of water taken (w/c ratio 0.7) =

50. RESULT:

Slump obtained for various water-cement ratio are,







DISCUSSION:


SL
NO
Name of works Slump (mm)
Water-cement
ratio
1
Concrete for roads and mass
concrete
25 – 50 0.70
2
Concrete for R.C.C slabs and
beams
50 - 100 0.55
3 Columns and retaining walls 75 - 125 0.45
4 Mass concrete in foundation 25 - 50 0.70







Water-cement ratio Slump (mm)
0.50
0.60
0.70

51. Exp No: Date:
COMPACTION FACTOR TEST

AIM:

To determine the workability of fresh concrete by compaction factor test

APPARATUS USED:

5. Compaction factor apparatus
6. Weighing balance
7. Trowel
8. Graduated cylinder

THEORY:

Compaction Factor Test is designed in such a way that it can be used only in
laboratory but in some cases, it can be used for field concrete tests. This test
works on the principle of determining the degree of compaction achieved by a
standard amount of work done by allowing the concrete to fall through a
standard height. The degree of compaction, called the compacting factor is
measured by the density ratio i.e., the ratio of the density actually achieved in
the test to density of same concrete fully compacted.

52. PROCEDURE:

1. One mix prepared with water-cement ratio is 0.50. And take 10 kg of
coarse aggregate, 5 kg of sand and 2.5 kg of cement.
2. Keep the apparatus on the ground and apply grease on the inner surface
of the cylinders.
3. Weight the empty cylinder – W1
4. With the help of hand scoop/trowel without compacting fill the freshly
mixed concrete in upper hopper part gently and carefully and within two
minutes release the trap door so that the concrete may fall into the lower
hopper such that it bring the concrete into standard compaction.
5. Open the trap door of the lower hopper, so that the concrete falls into the
cylinder below.
6. Remove the excess concrete above the level of the top of the cylinder.
Clean the outside of the cylinder.
7. Weight the concrete in the cylinder. Find the weight of partially
compacted concrete with cylinder - W2
8. Empty the cylinder and refill with concrete in four layers, 25 blows with
tamping rod. Top surface is levelled.
9. Find the weight of this fully compacted concrete with the cylinder - W3
10. Compaction factor can be calculated as
Compaction factor =
w2−w1
w3−w1


W1 = Weight of cylinder
W2 =weight of partially compacted concrete with cylinder
W3 = fully compacted concrete with cylinder

53. OBSERVATIONS AND CALCULATIONS:
Water content=0.5
Weight of partially compacted concrete, W2 = ………….
Weight of fully compacted concrete, W3 = ………….

Compaction factor =
w2−w1
w3−w1

54. RESULT:

Compaction factor of given concrete mix is obtained as ………


DISCUSSION:

55. Exp No: Date:
COMPRESSIVE STRENGTH OF CONCRETE

AIM:

To determine the compressive strength of concrete cubes.

APPARATUS USED:

1. Compression Testing Machine (CTM) or Universal Testing Machine
(UTM)
2. Cube moulds.
3. Trowel

THEORY:
Compressive strength of concrete depends on many factors such as water-
cement ratio, cement strength, quality of concrete material, and quality control
during production of concrete etc. Test for compressive strength is carried out
either on cube or cylinder. Various standard codes recommends concrete
cylinder or concrete cube as the standard specimen for the test. American
Society for Testing Materials ASTM C39/C39M provides Standard Test
Method for Compressive Strength of Cylindrical Concrete Specimens.

56. PROCEDURE
1. Mix the concrete either by hand or in a laboratory batch mixer
2. Clean the mounds and apply oil. Fill the concrete in the moulds in layers
approximately 5 cm thick. Compact each layer with not less than
35strokes per layer using a tamping rod (steel bar 16mm diameter and
60cm long, bullet pointed at lower end).
3. Level the top surface and smoothen it with a trowel
4. Curing - The test specimens are stored in moist air for 24 hours and after
this period the specimens are marked and removed from the moulds and
kept submerged in clear fresh water until taken out prior to test.
5. Remove the specimen from water after specified curing time and wipe
out excess water from the surface.
6. Take the dimension of the specimen to the nearest 0.2 m.
7. Clean the bearing surface of the testing machine
8. Place the specimen in the machine in such a manner that the load shall be
applied to the opposite sides of the cube cast.
9. Align the specimen centrally on the base plate of the machine.
10. Rotate the movable portion gently by hand so that it touches the top
surface of the specimen.
11. Apply the load gradually without shock and continuously at the rate of
140 kg/cm
2
/minute till the specimen fails.
12. Record the maximum load and note any unusual features in the type of
failure.

57. OBSERVATIONS AND CALCULATIONS:

Size of the cube = 15 cm x 15 cm x 15 cm
Area of the specimen = 225 cm
2


Characteristic compressive strength (fck)at 7 days =
Expected maximum load = fck x Area x FOS =
Range to be selected is …………………..

Characteristic compressive strength (fck)at 28 days =
Expected maximum load = fck x Area x FOS =
Range to be selected is …………………..

Maximum load applied =……….tones = ………….N
Compressive strength =……………N/mm
2

58. RESULT:

Average compressive strength (at 7 days) = ………….N/mm
2

Average compressive strength (at 28 days) =………. N/mm
2


DISCUSSION:
The strength of concrete increases with age. Table shows the strength of
concrete at different ages in comparison with the strength at 28 days after
casting.
Age Expected Strength
1 day 16%
3 days 40%
7 days 65%
14 days 90%
28 days 99%

59. Exp No: Date:
CONCRETE MIX DESIGN – IS METHOD
AIM:
To prepare concrete mix design of concrete by IS method

THEORY:

The process of selecting suitable ingredients of concrete and determining their
relative amounts with the objective of producing a concrete of the required,
strength, durability, and workability as economically as possible, is termed the
concrete mix design. For e.g., a concrete mix of proportions 1:2:4 means that
cement, fine and coarse aggregate are in the ratio 1:2:4 or the mix contains one
part of cement, two parts of fine aggregate and four parts of coarse aggregate.
The concrete mix design proportions are either by volume or by mass. The
water-cement ratio is usually expressed in mass.
PROCEDURE:
CONCRETE MIX DESIGN AS PER IS 10262 -2000
A-1

STIPULATIONS FOR PROPORTIONING

a) Grade designation

M40


b) Type of cement

OPC 43 Grade


c) Max nominal size of agg

20


d) Minimum cement content

320


e) Maximum water cement ratio

0.45


f) Workability (Slump)

100


g) Exposure condition

Severe


h) Method of concrete placing

Pumping


i) Degree of supervision

Good

60. j) Type of aggregate

Crushed angular
aggregate


k) Maximum cement content

450


l) Chemical admixture type

Super plasticizer



A-2

TEST DATA FOR MATERIALS

a) Cement used


b) Specific gravity of cement

3.15


c) Chemical admixture

Super plasticizer


d) Specific gravity of :



1) Coarse aggregates

2.74


2) Fine aggregate

2.74


e) Water absorption



1) Coarse aggregates

0.50%


2) Fine aggregate

1%


f) Free (Surface) moisture



1) Coarse aggregates

Nil


2) Fine aggregate

Nil


g) Sieve analysis:



1) Coarse aggregates





IS sieve
sizes mm
Analysis of coarse
aggregate fraction
(Percent passing)
Percentage of different
fractions
Combined


I II I II


20 mm 10 mm 50% 50%


40 100 100 50 50 100


20 97.8 100 48.9 50 98.9


10 1.6 79.3 0.8 39.65 40.45


4.75 9.8 0 4.9 4.9

61. 2) Fine aggregate






IS sieve
size mm
Percent
passing by
weight


10 100


4.75 97.3


2.36 86.8


1.18 65.7


0.6 53.3


0.3 11.9


0.15 3.1


Fineness Modulus 3.18





CALCULATIONS FOR MIX DESIGN


A-3

TARGET STRENGTH FOR MIX PROPORTIONING



Target mean strength of concrete N/mm
2
,


f
1
ck = fck + 1.65 S


= 48.25N/mm²



f
1
ck = Target average compressive strength at 28 days


fck = Characteristic compressive strength at 28 days


S = Standard deviation (Table 1), S = 5 N/mm
2



A-4

SELECTION OF WATER -CEMENT RATIO



From Table 5 of IS 456, maximum water cement ratio of M40 mix = 0.45

Based on experience, adopt water-cement ratio as 0.40

0.40 < 0.45, therefore OK.




A-5

SELECTION OF WATER CONTENT

62. From Table 2, maximum water content = 186 Litre (for 25-50 mm slump range)
for 20 mm aggregate


Estimated water content for 100 mm slump = 186 +6/100 x 186 = 197 Litre


As superplasticizer is used, the water content can be reduced upto 20 % and above.
Based on trials with superplasticizer water content reduction of 29 % has achieved.
Hence the water = 140 Litre

Arrived water content =
197 x
0.71 = 140 litre



A-6



CALCULATION OF CEMENT CONTENT


Water-cement ratio = 0.4



Cement content = 350 kg/m
3



A-7

PROPORTION OF VOLUME OF COARSE AND FINE AGGREGATE PROPORTION


Volume of coarse aggregate = 0.56


Volume of fine aggregate = 0.44



A-8

MIX CALCULATIONS


a) Volume of concrete = 1 m
3



b) Volume of cement = 0.1111 m
3



c) Volume of water = 0.14 m
3



d)
Volume of chemical admixture (@2%by
mass of cementitious material)
= 0.0061 m
3



e) Volume of all in agg = 0.7428 m
3



f) Mass of coarse agg = 1139.7 kg


g) Mass of fine aggregate = 895.49 kg

63. A-9

MIX PROPORTION


Cement = 350 kg/m
3



Water = 140 kg/m
3



Fine aggregate = 895.49 kg


Coarse aggregate = 1139.7 kg


Chemical Admixtures = 7 kg/m
3



Water-cement ratio = 0.4


Cement:Fine:Coarse

=




RESULT:
Mix proportion is obtained as,
Cement =
Water =
Fine aggregate =
Coarse aggregate =
Chemical admixture =
Water-cement ratio =

DISCUSSION: