Civil engineering materials lab manual revised

OBJECTIVES:
The objective of this course is to introduce the students with the various test necessary for Civil
Engineering Construction Materials. The primary emphasis of the course is on fundamental
understanding of the underlying principles of the topics that have been discussed in the lectures
using various experimental techniques, instruments and apparatus. This laboratory course
involves the study of instrumentation and philosophical content that should help to serve as a
foundation for the future professional career of Civil engineers. In general, there might not be a
single unique answer to the laboratory problems. Then, the student may determine the best
'answer' possible within the framework of the equipment available, the estimated errors, etc. The
teaching staff have all solved similar problems before and can assist with the procedures and
techniques required for the successful completion of the experiment. Hence, success in the
course will depend upon the student's own initiative and ideas toward the problem solving in a
given experiment. The experimentation work is divided into four groups.
 Tests for Cement
 Tests for Fine Aggregates
 Tests for Coarse Aggregates
 Tests for Compressive Strength
This laboratory manual available to all students at the beginning of the semester contains the
detailed information about the experiment objectives with each having a brief introduction, a
short description of the facility, suggestions for summary and a few references. Students must
prepare themselves for the next scheduled experiment following the appropriate hand-out.
Teaching Assistants conduct brief quizzes before students are allowed access to the experimental
set-up to make sure students are ready. Students will not be allowed to perform the experiment
without satisfactory knowledge of the expected work in the laboratory.

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LIST OF EXPERIMENTS:
SR.NO EXPERIMENTS Specification
PAGE
NO
1 Gradation of Concrete Fine Aggregates ASTM C-136 4
2
Gradation of Concrete Coarse Aggregates ASTM C-136 8
+
3
Fineness of Hydraulic Cement by the Sieve #200
ASTM C-430
11
4
Standard Test Method for Density, Specific Gravity and
Absorption of Fine Aggregate
ASTM C-128 13
5
Absorption of Coarse Aggregate
ASTM C-127 17
6
Standard Test Method for Bulk Density (Unit Weight) in
Aggregate ASTM C-29 19
7 Impact Value Test for coarse Aggregate ASTM C-535 21
8
Standard Test Method for Normal Consistency of Hydraulic
Cement ASTM C-187 24
9
Standard Test Methods for Time of Setting of Hydraulic
Cement by Vicat Needle
ASTM C-191 26
10 Standard test method for slump of hydraulic cement concrete ASTM C-143 29
11 To determine the compressive strength of cement mortar ASTM C-109 35
12 Standard Test Methods for Water Absorption of Bricks ASTM C-67 38

3
EXPERIMENT No #1
Gradation of Fine Aggregate by Sieve analysis (ASTM C-136)
OBJECTIVE:
This test method covers the determination of the particle size distribution of fine aggregates by
sieving.
APPARATUS
Weighing machine, ASTM Standard sieve set, pan & electric sieve shaker.
Figure1: ASTM Standard sieve set
THEORETICALBACKGROUND:
The purpose of the sieve analysis is to check the aggregate that we are using is suitable for use
and fulfill our requirement or not. If the requirements come between fines range then the
aggregate is suitable for use in any construction work. It also gives information about the
maximum number of size aggregates present in the sample. For fine aggregate the fines modulus
must be between 2.3 and 3.2.is recommended by ASTM. If else this value then the fine aggregate
is not suitable for use in any construction work

4
PROCEDURE:
1. Place the sieves on top of each other (#4, #8, #16, #30, #50, #100 and pan).
2. Place the highest Sieve No. on top and place below it the decreasing No of Sieve.
3. Now take sample as you required.
4. Take minimum 300g sample of fine aggregate.
5. Put the entire sample on top sieve and shake it.
6. The least time for shaking is 10 minutes.
7. After suitable shaking place the sample in the pan and weight it.
8. Continue the process till the last sieve.
9. Find the sample retained on each sieve.
RESULTS & CALCULATION
Now find the sample retained on each sieve by using formula:
Calculate % retained on sieve =Retained weight * 100
Total weight
Then calculate the cumulative % passing and cumulative % retained.
Finally calculate fines modulus by using formula = ∑Cumulative % retained
100
Plot the particle size distribution against the ASTM limits

5
Figure 1: ASTM Maximum & Minimum Limitations

6
Observation Table:
Sieve analysis of Fine Aggregate
Sieve
#
Sieve
size
Weight
Retained
(gm)
%
retained
%
passing
Cumulative
% passing
Cumulative
%
Retained
ASTM Specs %
passing
Minimum Maximum
Pan 0 0
#100 2 10
#50 10 30
#30 25 60
#16 50 85
#8 80 100
#4 95 100
Fineness Modulus = ______________

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EXPERIMENT No #2
Gradation of Coarse Aggregate by Sieve analysis
(ASTM C-136)
OBJECTIVE:
This test method covers the determination of the particle size distribution of coarse aggregates by
sieving.
APPARATUS
Weighting machine, ASTM Standard sieve set, pan & electric sieve shaker.
Figure 2: ASTM Standard sieve set
The purpose of the sieve analysis is to check the aggregate that we are using is suitable for use
and fulfill our requirement or not. It also gives information about the maximum number of size
aggregates present in the sample.

8
PROCEDURE:
1. First place the sieves on top of each other.
2. Place the highest Sieve No. on top and place below it the decreasing no of Sieve No.
3. Now take sample as you required.
4. Take minimum 2000g sample of fine aggregate.
5. Put the entire sample on top sieve and shake it.
6. The least time for shaking is 10 minutes.
7. After suitable shaking place the sample in the pan and weight it.
8. Continue the process till the last sieve.
9. Find the sample retained on each sieve.
Now find the sample retained on each sieve by using formula:
% retained on sieve = retained weight * 100
Total weight
Then calculate the cumulative % passing and cumulative % retained.
Plot the particle size distribution against the ASTM limits

Sieve analysis of Coarse Aggregate
Sieve
#
Sieve
size
Weight
Retained
(gm)
%
retained
%
passing
Cumulative
% passing
Cumulative
%
Retained
ASTM Specs %
passing
Minimum Maximum

10
EXPERIMENT No #3
Standard Test Method for Fineness of Hydraulic Cement by
the Sieve # (No. 200) (ASTM C-430)
OBJECTIVE:
This test method covers the determination of the fineness of hydraulic cement by means of the
45-μm (No. 325) sieve.
APPARATUS
Weighting machine, sieve # 200, pan & electric sieve shaker.
Figure 1: ASTM sieve # 200
PROCEDURE:
1. Take 100g sample of cement and put it in a sieve # 200.
2. Shake for 15 minutes.
3. After that weight the sample retained on the sieve.
4. If it comes 10g i.e. 10% of given sample weight then it is fresh because 90% has passed
through sieve # 200, otherwise not.

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Weight of Cement sample taken (W1) = ______________
Weight retained on Sieve (W2) = ______________
% of fines of Cement
)
100
W1
W2
-
W1
( 
= ______________

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EXPERIMENT No # 4
Absorption of Fine Aggregate (ASTM C-128)
OBJECTIVE:
This test method covers the determination of the average density of a quantity of fine aggregate
particles (not including the volume of voids between the particles), the relative density (specific
gravity), and the absorption of the fine aggregate.
APPARATUS:
Weighting machine, Water tank, Sieves, Oven
Depending on the procedure used, the density, in kg/m3 or lb/ft3 is expressed as oven-dry (OD),
saturated-surface-dry (SSD), or as apparent density. Likewise, relative density (specific gravity),
a dimensionless quality, is expressed as OD, SSD, or as apparent relative density (apparent
specific gravity). The OD density and OD relative density are determined after drying the
aggregate. The SSD density, SSD relative density, and absorption are determined after soaking
the aggregate in water for a prescribed duration.
Figure 1: Moisture Conditions of Aggregates
DAMP OR WET:
Aggregate in which the pores are filled with water and with free water also on their
surface.

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SATURATED SURFACE DRY (SSD):
Aggregate in which the pores are filled with water but with no free water on the surface.
AIR DRY (AD):
Aggregate that has a dry surface but contains some water in the pores.
OVEN DRY (OD):
Aggregate that contains no water in the pores or on the surface.
DENSITY:
Density of material is defined as mass per unit volume. Density of water is 1000kg/m3,
1g/cc or 62.4lb/ft3.
SIGNIFICANCE OF DENSITY:
If a minimum density is specified, for example, in heavy weight concrete for nuclear
radiation shielding and the aggregates used in concrete have density less than the specified value
then the concrete used for nuclear radiation shielding will not be able to absorb nuclear
radiations and it will not fulfill its purpose.
SPECIFIC GRAVITY:
The specific gravity of an aggregate is the mass of the aggregate in air divided by the
mass of an equal volume of water.
SPECIFIC GRAVITY (OVEN DRY):
Specific gravity (oven dry) of an aggregate is the oven dry mass divided by the mass of a
volume of water equal to the saturated surface dry aggregate volume.
SPECIFIC GRAVITY (SATURATED SURFACE DRY):
Specific gravity (saturated surface dry) of an aggregate is the saturated surface dry mass
divided by the mass of a volume of water equal to the saturated surface dry aggregate volume.
SPECIFIC GRAVITY (APPARENT):
Specific gravity (apparent) of an aggregate is the oven dry mass divided by the mass of a
volume of water equal to that of the solid including the impermeable pores.
SIGNIFICANCE OF SPECIFIC GRAVITY:
The specific gravity of an aggregate is used in mixture proportioning calculations to find
the absolute volume that a given mass of material will occupy in the mixture. Absolute volume

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of an aggregate is the volume of solid matter and internal pores excluding the spaces between the
particles. The absolute volume is used to calculate the volume of a batch of concrete.
In a given concrete mixture, substituting one aggregate with another of a different specific
gravity will cause the volume of concrete to change for the same batch mass. Because concrete is
often sold by volume, this change means that either the purchaser is receiving less concrete than
ordered or the producer is supplying more concrete than purchased. Specific gravity can also
indicate possible material contamination. Deleterious particle are often lighter than aggregate
particles and therefore a large amount of deleterious material in an aggregate sample may result
in an abnormally low specific gravity.
Absorption:
The increase in mass of aggregate due to water penetration into the pores of the particles
is called absorption.
Significance of Absorption:
To calculate the amount of mixing water in a concrete batch, it is necessary to know the
amount of water absorbed by the aggregates. If absorption value is not known then the total
water needed for concrete cannot be determined accurately.
PROCEDURE:
1. Partially fill the graduated cylinder with water.
2. Add 500g of saturated surface dry (SSD) fine aggregate in graduated cylinder.
3. Agitate the graduated cylinder to eliminate all air bubbles.
4. After eliminating air bubbles bring the water level in graduated cylinder to its calibrated
capacity.
5. Determine the total mass of the graduated cylinder, specimen and water.
6. Remove the fine aggregate from the graduated cylinder, dry in the oven at a temperature
of 110 degree centigrade, allow cooling in air at room temperature for 1 hour and
determining it’s mass.
7. Fill the graduated cylinder to its calibrated capacity with water and determine it’s mass.
Specific gravity (oven dry) = A/ (B + S – C)
Specific gravity (saturated surface dry) = S/(B+S – C)
Specific gravity (apparent) = A/ (B+A-C)

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Absorption % = (S-A)/A x 100
Where
S = mass of saturated surface dry specimen (g)
A = mass of oven dry specimen (g)
B = mass of graduated cylinder filled with water to its calibrated mark (g)
C = mass of graduated cylinder filled with specimen and water to calibration mark (g)

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EXPERIMENT No # 5
Absorption of coarse aggregate (ASTM C-127)
OBJECTIVE:
This test method covers the determination of the average density of a quantity of coarse
aggregate particles (not including the volume of voids between the particles), the relative density
(specific gravity), and the absorption of the coarse aggregate.
APPARATUS
Weighting machine, Water tank, Sieves, Oven
Depending on the procedure used, the density (kg/m3or lb/ft3) is expressed as oven-dry (OD),
saturated surface-dry (SSD), or as apparent density. Likewise, relative density (specific gravity),
a dimensionless quantity, is expressed as OD, SSD, or as apparent relative density (apparent
specific gravity). The OD density and OD relative density are determined after drying the
aggregate. The SSD density, SSD relative density, and absorption are determined after soaking
the aggregate in water for a prescribed duration.
PROCEDURE:
1. Dry the test sample in the oven to constant mass at a temperature of 110 ± 5 degree
centigrade. Then cool it in air at room temperature for 1 to 3 h or until the aggregate has
reached a temperature that is comfortable to handle.
2. Immerse the coarse aggregate in water for 24 hours.
3. Remove the test sample from water and roll it in a large absorbent cloth to remove water
from surface.
4. Determine the mass of the test sample in saturated surface dry condition.
5. After determining the mass place the saturated surface dry sample in sample container,
determine its apparent mass in water.
6. Remove all entrapped air before determining its mass by shaking the container while
immersed.
7. Dry the test sample in oven at temperature of 110 degree centigrade, cool in air at room
for 1 to 3 hours or until the aggregate is comfortable to handle and determine its mass.

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Specific gravity (oven dry) = A/(B-C)
Specific gravity (saturated surface dry) = B/(B-C)
Specific gravity (apparent) = A/(A-C)
Absorption % = (B-A)/B x 100
Where
A= mass of oven dry test sample in air (g)
B= mass of saturated surface dry test sample in air (g)
C= apparent mass of saturated test sample in water (g)

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EXPERIMENT No # 6
Standard Test Method for Bulk Density (Unit
Weight) in Aggregate (ASTM C-29)
OBJECTIVE:
This test method covers the determination of bulk density ("unit weight") of aggregate in a compacted or
loose condition and calculated voids in fine, coarse, or mixed aggregates based on the same
determination.
APPARATUS:
Weight Balance, Unit Mould, Tamping Rod, Scoop
This test method is often used to determine bulk density values that are necessary for use for
many methods of selecting proportions for concrete mixtures. The bulk density also may be used
for determining mass/volume relationships for conversions in purchase agreements. However,
the relationship between degree of compaction of aggregates in a hauling unit or stockpile and
that achieved in this test method is unknown. Further, aggregates in hauling units and stockpiles
usually contain absorbed and surface moisture (the latter affecting bulking), while this test
method determines the bulk density on a dry basis.
PROCEDURE:
1. Find the empty weight of the metal measure.
2. Fill the measure one-third full with the dry sample.
3. Rod the layer of aggregate with 25 strokes. (Do not allow the rod to strike the bottom of
the measure)
4. Fill the measure two-thirds full, level, and rod as in step 3.
5. Fill the measure overflowing and rod as in step 3.
5. Level the surface of the aggregate with a finger and tamping rod such that any slight
projection of the larger pieces of the coarse aggregate approximately balances the larger
voids in the surface below the top of the measure.
7. Weigh the measure with the aggregate and find the net weight of the aggregate: A.
8. Calculate the unit weight B:
Unit eight or bulk density, B = (A/V) lb/ft3 or kg/m3
where V is the volume of the measure.

19
9. Calculate the void content or percent void.
Void % = (S x W – B)/(S x W) x 100
Where S is the bulk specific gravity (dry basis from the specific gravity of coarse
aggregate experiment) and W is the unit weight of water (62.4 pcf or 999 kg/m3)
Report: Calculate unit weight for the aggregate. Comment on the results.

20
EXPERIMENT No # 7
Impact Factor Test for Coarse Aggregates
OBJECTIVE:
This determines the toughness of stones i.e., the resistance of the fracture under repeated impacts
may be called an impact test for aggregate.
APPARATUS:
Impact testing machine, cylindrical metal measure having internal diameter 75mm and depth
50mm for measuring impact value of aggregates. Tamping rod: 10mm in diameter and 230mm
long, rounded at one end. Sieve of sizes 12.5mm, 10mm, and 2.36mm for sieving the
aggregates, Balance& Oven with constant temperature between 100C to110C.
Figure 1: Impact value Test

21
Toughness is the property of a material to resist impact. Due to loads, the aggregate are subjected
to the pounding action or impact and there is possibility of stones breaking into smaller pieces.
And so it should therefore be tough enough to resist fracture under impact.
PROCEDURE:
1. Take a test sample consisting of aggregates passing 12.5mm (0.5in) sieve and retained on
10mm (0.375in) sieve and dried in an oven for four hours at a temperature 100oC to
110oC and cooled.
2. Test aggregates are filled up to about one-third full in the cylindrical measure and tamped
25 times with rounded end of the tamping rod.
3. Further quantity of aggregates is then added up to two-third full in the cylinder and 25
stocks of the tamping rod are given.
4. The measure is now filled with the aggregates to over flow, tamped 25 times.
5. The surplus aggregates are struck off using the tamping rod as straight edge.
6. The net weight of the aggregates in the measure is determined to the nearest gram and
this weight of the aggregates is used for carrying out duplicate test on the same material.
7. The impact machine is placed with its bottom plate flat on the floor so that the hammer
guide columns are vertical.
8. The cup is fixed firmly in position on the base of the machine and the whole of the test
sample from the cylindrical measure is transferred to the cup and compacted by tamping
with 25 strokes.
9. The hammer is raised until its lower face is 380mm above the upper surface of the
aggregates in the cup, and allowed to fall freely on the aggregates.
10. The test sample is subjected to a total 15 such blows, each being delivered at an interval
of not less than one second.
11. The crushed aggregate is then removed from the cup and the whole of it sieved on the
2.36mm sieve (sieve no 8) until no further significant amount passes.
12. The fraction passing the sieve is weighed accurate to 0.1gm.
13. The fraction retained on the sieve is also weighed and if the total weight of the fractions
passing and retained on the sieve is added, it should not be less the original weight of the
specimen by more than one gram.
14. If the total weight is less than the original by over one gram the results should be
discarded and a fresh test made.

22
CALCULATIONS:
The aggregate impact value is expressed as the percentage of the fines formed in terms of the
total weight of the sample. .
Aggregate Impact Value = W2/W1 X 100
W2= Weight of sample Passing through Sieve # 2.36mm
W1= Total Weight of Sample Taken for test
LIMITATIONS
< 10% exceptionally strong,
10–20% Strong,
20–30% Satisfactory for road surfacing
> 35%Weak for road surfacing

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EXPERIMENT No # 8
Standard Test Method for Normal Consistency of
Hydraulic Cement (ASTM C-187)
OBJECTIVE:
To determine the quantity of water for cement paste for normal consistency.
APPARATUS:
Vicat needle apparatus with plunger of 10mm dia, trowel, balance, etc.

24
The percentage of water by weight of cement which produces a consistency which permits
plunger having diameter 10 mm, to penetrate up to depth of 5 to 7 mm above the bottom of
mould is called the normal consistency of cement paste.
PROCEDURE:
1. Take 400 gm of cement and place it in an enamel trough.
2. Add 25% of water in dry cement and mix it. The gauging time should not be less than 3
minutes and not more than 5 minutes. The gauging time is time consumed from adding of
water in dry cement to commencing to fill the mould.
3. After mixing properly, fill the Vicat mould with this paste.
4. Level the surface of cement with the top of the mould.
5. Place the mould on the non-porous plate under the plunger of apparatus and adjust the
indicator in such a way that it shows zero reading when plunger touches the bottom of
mould (i.e., non-porous plate.)
6. Release the plunger and note down the reading.
7. If the penetration is less than the desired one then make another trial sample by
increasing water content and find the penetration.
8. Repeat the step 7 until the desired penetration, i.e. penetration up to 5 to 7 mm, above the
bottom is achieved.
OBSERVATIONS:
S.No
Quantity of
Cement
Quantity of
Water
% of water by
weight
Penetration above
from bottom
Results
Normal Consistency of cement paste=
Brand of Cement used : ___________________________
Normal Consistency : ___________________________

25
EXPERIMENT No #9
Standard Test Methods for Time of Setting of Hydraulic
Cement by Vicat Needle(ASTM C-191)
OBJECTIVE:
To determine the initial and final setting time of cement.
APPARATUS
Vicat’s needle apparatus, balance, stop watch, etc.
Figure 3: Vicat Apparatus with needle
Initial setting time is the time consumed from addition of water into dry cement to the instant at
which needle of 1 mm2 section fails to pierce the test sample to a depth of 5 mm from the
bottom. Final setting time is time consumed from addition of water into dry cement to the instant
at which needle of 1 mm2 with 5 mm dia attachment makes an impression on the sample but
attachments fails to make it.

26
PROCEDURE:
1. Weigh 400 gm of cement and place it in an enamel trough.
2. Add 0.85 P % water by weight of cement and mix it thoroughly, where P is the normal
consistency of cement.
3. Fill the mould with cement paste and level off the cement surface with the top of mould.
The gauging time should not be less than 3 minutes and should not be more than 5
minutes.
4. Place the mould on non-porous plate under the needle of apparatus.
5. Bring the needle in contact with the cement surface and release it.
6. Repeat the step (5) after every 2 minutes until the needle fails to pierce the sample for
about 5 mm measured from the bottom of the mould, note down this time. It is initial
setting time.
7. Replace the needle by needle with an annular attachment.
8. Bring the needle with attachment near the surface of cement and release it.
9. Repeat the step (8) until the needle makes an impression on surface and attachment does
not make impression.
10. Note down this time also.
OBSERVATIONS:
Quantity of cement=
Normal Consistency=
Quantity of water=
Initial setting time=
Final setting time=
CALCULATION
Quantity of water required = 0.85 x P x wt. of cement/100=
RESULT:
Initial setting time=
Final setting time=

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Brand of Cement used : ___________________________
Initial Setting Time (IST) : ___________________________
Final Setting Time (FST) : ___________________________

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EXPERIMENT No # 10
Determine the SLUMP of concrete by SLUMP-TEST (ASTM C-
143)
OBJECTIVE:
This test is performed to check the workability of freshly made concrete.
APPARATUS:
Slump test apparatus, 5/8” tampering rod, Measuring Balance
Mold in the form of the lateral surface of the frustum of a cone with the base 8 inch in diameter,
the top 4 inch in diameter and the height 12 inch. Tamping rod: A round, straight steel rod 5/8
inch in diameter and approximately 24 inch in length, having the tamping end or both ends
rounded to a hemispherical tip, the diameter of which is 5/8 inch.
Consistency is a term very closely related to workability. It is a term which describes the state of
fresh concrete. It refers to the ease with which the concrete flows. It is used to indicate the degree
of wetness. Workability of concrete is mainly affected by consistency i.e. wetter mixes will be
more workable than drier mixes, but concrete of the same consistency may vary in workability.
It can also be defined as the relative plasticity of freshly mixed concrete as indicative of its
workability. So concrete may have the following types of consistency:
PLASTIC CONSISTENCY:
When it can be shaped into a ball between the palms of hands and adheres to the skin.
SEMI-FLUID CONSISTENCY:
This cannot be rolled into a ball but spreads out without affecting the cohesion of the
constituents so that segregation doesn’t take place.
FLUID CONSISTENCY:
Which spreads out rapidly and segregation takes place.
Thus different degree of workability is required at different occasions. If the structure is RCC
and the steel bars too much close to each other than high workability is required i.e. fluid
consistency. While where the inter bars space is large than concrete of semi-fluid or plastic
consistency is required

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Figure 1: Slump Apparatus
PROCEDURE:
1. Prepare a mixture of concrete having ratio of 1:2:4. That is one part of cement, two parts
sand, and four parts of crush.
2. For this first of all determine the volume of the cone in cubic feet.
3. It is determined by taking the mean diameter of the cone and with it finding the area of
the cross section of cone.
4. Then multiplying it with the height of the cone which is 1 foot, will give the volume of
the cone.
5. This is the volume of concrete which have to be prepared so that the cone is fully
compacted.
6. Then determine the total weight of the concrete, as the specific weight of concrete is 150
lb/ft3.
7. Then determine the weight of cement by multiplying the weight of concrete by 1/7, as
cement is one part out of total 7 parts.
8. Then determine the weight of sand by multiplying the weight of concrete by 2/7, as sand
is two parts out of total 7 parts.
9. Then determine the weight of crush by multiplying the weight of concrete by 4/7, as
crush is four parts out of total 7 parts.
10. After calculation of dry ingredients, calculate the amount of water as is given in the
ASTM Standard water-cement ratio. For 1:2:4 mixture the water-cement ratio is 0.6, so
for weight of water to be added, multiply this ratio with weight of cement.
11. After calculation of weights make a homogeneous mixture of dry ingredients, and then
add water carefully to make a paste.

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12. Then take the slump-test apparatus and clean it from inside also apply oil to it and to the
bottom surface.
13. Then place it on the smooth metallic surface, and fix it firmly.
14. Then put one third of the concrete in the cone and press it with the help of a 5/8 inch,
round-ended, tampering rod.
15. It should be tampered 25 times.
16. Then add the second one-third portion of concrete, and also tamper it 25 times with the
help of tampering rod.
17. At last add the remaining one-third portion, and also tamper it 25 times.
18. For the upper surface to be smooth work it with float, so that during measurement of
slump it is easy to take correct readings.
19. Immediately after filling the cone is slowly lifted, and the unsupported concrete will now
slump, hence the name of the test. “The decrease in the height of the centre of the
slumped concrete is called slump”.
Figure 2: Slump measurement
RESULTS:
The slump test gives the following three results:
 TRUE-SLUMP: if the concrete subsides evenly then it is called true-slump, and is aimed
to be calculated.
 SHEAR-SLUMP: If one half of the cone slides down, it is called shear-slump and is
difficult to measure. It occurs in harsh mixes (mixes deficient in fine aggregate).
 COLLAPSE-SLUMP: If the concrete slides down as soon as the mould is removed, it is
known as collapse-slump. It occurs in very wet mix.

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Figure 3: Type of Slump
CALCULATIONS:
Ratio of the concrete = 1:2:4
Sum of the ratio of concrete =1+2+4 = 7
Volume of the cone:
Mean diameter of the cone = Dm = 4+8/2 = 6 inch
Area of the cone =Ac = π*( Dm) 2 / 4
= π/4 *(6/12)2
= 0.1963 ft2
Volume of the cone = VC = 0.1963 ft2 * 1 ft
= 0.1963 ft3
Specific weight of concrete = γcon = 150 lb/ ft3
Weight of concrete = Wcon = γcon * Vc
= 150 * 0.1963
= 29.44 lb
Weights of dry materials:
Weight of cement = Wcem = 1/7 * Wcon
=1/7 * 29.4 = 4.2 lb ≈ 4 lb

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Weight of sand = Wsand = 2/7 * Wcon
= 2/7 * 29.4 = 8.44 lb ≈ 8 lb
Weight of crush = Wcrush = 4/7 * Wcon
= 4/7 *29.4 = 16.82 lb ≈ 16 lb
Weight of water:
Ratio of concrete = 1:2:4
ASTM-Standard water-cement ratio = w/c = 0.6
Weight of water = Water = 0.6 * Wcem
= 0.6 * 4
= 2.4 lb
Standard values of slump:
Description Slump in inches
Concrete for road construction ¾ to 1.5
Slabs 1 to 2
Normal RCC sections, e.g. slabs, beams, columns,
walls etc.
2 to 6
Thin RCC structures 4 to 7
Vibrated concrete ½ to 1
Mass concrete 1 to 3
OBSERVATIONS:
Slump of the concrete = ______ inch

33
COMMENTS:
_____________________________________________________________________________________

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EXPERIMENT No # 11
To Determine the Compressive Strength of cement mortar
(ASTM C-109)
OBJECTIVE:
To determine the compressive strength of concrete.
APPARATUS:
Compression Testing Machine, Measuring Balance, Steel Moulds
Cement is usually subjected to compressive stresses when used in the form of concrete or mortar.
Mortar is a mixture of cement and sand in a specified ratio on which the strength of the mortar
depends. If the mortar is weak then also its compressive strength is very low but if the mortar is a
strong one then its compressive strength is also very high. The mixture of sand and cement in
water is generally weak in tension and is strong in compression that is why when the concrete is
subjected to tensile forces then it is provided with steel rods in area of tension that is why it is
then called as reinforced concrete. Therefore it is obvious the mortar will be strong in
compression as compared to tension.
Mortar is generally used for brick masonry and plastering. In first case the mortar is subjected to
very high compressive loads such as the load of the wall above it, therefore it is very much
necessary to test the mortar for its compressive strength. For this purpose required cement-sand
mixture is prepared before its use and after a certain period of curing it is tested. The strength of
the mortar depends upon the fineness of cement, the gradation of sand and the most important
factor which water-cement ratio. If any one of the above factors be not according to the ASTM-
Standard then the strength of mortar is badly affected.
The standards of ASTM are provided for different ratios of mixture with which the test results
are compared and then decided for its use. These values are taken when the mortar is just
removed from curing.
PROCEDURE:
1. Prepare a mixture of cement and sand having ratio of: 1:3. That is one part of cement and
three parts sand.
2. We take the weight of cement equal to 200 grams and therefore the weight of sand equal
to 300 grams. This will make a 1:3 mortar.
3. Then calculate the amount of water for this ratio according to the ASTM standards.

35
4. This is 10% of the weight of total aggregate.
5. After calculation of weights make a homogeneous mixture of dry ingredients, and then
add water carefully to make a paste.
6. After this take the two inch cube mould and clean them thoroughly from inside and if
possible also apply some oil to the inner surface so that during removal of mould the
cubes are not damaged.
7. Also fix them tight so that during compaction it is easy to compact.
8.Then fill one third of the mould with mortar and press it with the help of a 5/8 inch, round-
ended, tampering rod.
9.It should be tampered 25 times.
10. Then fill the second one-third potion of mould, and also tamper it 25 times with the help
of tampering rod.
11. At last fill the remaining one-third portion, and also tamper it 25 times.
12. Adopting the same procedure as before, make six cubes of mortar so that we can take the
average of their strengths.
13. For the upper surface to be smooth work it with a float.
14. Then keep it is open air for one day.
15. Cure three of them for three days and the remaining three for six days by keeping them
immersed in water.
16. After curing of the cubes take them out of the moulds carefully and then bring them for
testing on compression machine.
17. Now place the test specimen in the compression machine & apply load to the test
specimen continuously and uniformly throughout the compression test.
18. As the load is applied on the cube it will develop cracks after certain load.
19. Discontinue the application of load when the cube has been crushed or just cracks are
developed in it.
20. Take out the cube and clean the compression plate surface for next test.
21. Continue the above procedure for the remaining cubes.
22. Note down the crushing load for each cube separately.
Compressive strength of 1:3 mortars ASTM C-109:
Cured or 3-Days:
Compressive strength = 3300 psi
Cured for 7-Days:
Compressive strength = 5900 psi

36
RESULTS & CALCULATIONS
S.No Crushing Load Area in2
Compressive Strength
1
2
3
Average Strength = ________________

37
EXPERIMENT No # 12
Standard Test Methods for Water Absorption of Bricks
(ASTM C-67)
APPARATUS:
Bricks, balance, oven
Procedure
1. Dry and cool the test specimens.
2. Saturation—Submerge the dry, cooled specimen, without preliminary partial immersion,
in clean water (soft,distilled or rain water) at 60 to 86°F (15.5 to 30°C) for the specified
time. Remove the specimen, wipe off the surface water with a damp cloth and weigh the
specimen. Complete weighing of each specimen within 5 min after removing the
specimen from the bath.
Calculate the absorption of each specimen as follows:
Absorption, % = 100(Ws - Wd) / Wd
Where:
Wd = dry weight of the specimen, and
Ws = saturated weight of the specimen after submersion in water.

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