Construction Material Manual

BDUEF school of civil and water
EXPERIMENT No. 1
Test Method for Standard consistency
1. Scope
This test method covers the determination of standard consistency and setting times
of cement sample.
2. Definition
Standard Consistency – This test method is intended to be used to determine the
amount of water required to prepare hydraulic cement pastes for testing. The consistency,
which will permit the vicat plunger to penetrate to a depth 9 –11 mm from the original
surface.
3. Apparatus
3.1 Vicat apparatus with vicat plunger
3.2 Vicat needle and vicat mould
3.3 Gauging trowel, measuring jar, mixer, weighing balance, stop watch and glass
plate.
4. Procedure
4.1 A 500gm sample of cement with a measured quantity of clean water is thoroughly
mixed with in 3 minutes by means of a trowel.
4.2 The cement paste is then filled in to the mould and centrally placed on a plate under
the rod. The temperature of the cement and water and that of the test room during
gauging and filling the mould should be 17.7-23.3 oc.
4.3 Immediately after filling the mould gently lowers the plunger and brought in contact
with the surface of the paste and quickly released. Thirty seconds after releasing the
plunger, the penetration is recorded.
4.4 The test is repeated with fresh trial pastes with varying percentage of water until
standard consistence is obtained.
4.5 The amount of water required for normal consistence is expressed as a percentage by
weight of the dry cement..
% Water =(A/500gm) *100
Where: A= Weight of water taken
The usual range of water / cement ratio for normal consistence is between 26 and 33
percent.
Construction materials lab. Manual 1

5. Observation
OBSERVATION SHEET
STANDARD CONSISTENCY OF CEMENT
Trial Percentage of Un penetrated Depth From the

No water taken bottom(mm)
1
2
3
6. Result
Standard consistence of cement =

EXPERIMENT No. 2
Time of setting of Hydraulic cement by Vicat Needle
SETTING TIMES
1. Scope
These methods determines the time of hydraulic cement by means of vicat needle.
Two test methods are given; method A is the reference of Test Method using the manual
operated standard Vicat apparatus, while Method B permits the use of an automatic vicat
machine that has, in accordance with the qualification requirements of this method,
demonstrated acceptable performance.
2. Definition
Setting times – The setting time measures the time taken for the cement paste to offer
certain degree of resistance to the penetration of a special attachment pressed in to it. The
time of setting is calculated as the difference between the time that a measurement of 25
mm penetration is measured and the time of the initial contact between the cement and
water.
3. Apparatus
3.1 Vicat apparatus with vicat plunger
3.2 Vicat needle and vicat mould
3.3 Gauging trowel, measuring jar, mixer, weighing balance, stop watch and glass
plate.
4. Procedure
4.1 A fresh cement paste of normal consistence is prepared and filled into the vicat
mould.
4.2 About 30 minutes after mixing, the mould resting on a plate is placed under the
rod and the needle is gently lowered and brought in contact with the surface of the
[paste and quickly released. Thirty seconds after releasing the needle the
penetration is recorded. This is repeated every 15 minutes until a penetration of
25mm or less is obtained in thirty seconds.
4.3 The results of all penetration tests are recorded, and the time when a penetration
of 35mm is obtained is determined by interpolation. The period elapsing between
the time when the water is added to the cement and the time at which the needle
penetrates 25mm is taken as the initial setting time.
4.4 For the determination of the final setting time the needle of the Vicat apparatus is
replaced by the needle with an annular attachment. The cement shall be
considered as finally set when, upon applying the needle gently to the surface of
the test block, only the needle makes an impression, while the attachment fails do
so.

5. Observation
OBSERVATION SHEET
INITIAL SETTING TIMES OF CEMENT
Trial Time in min. Un penetrated Depth From the

No bottom(mm)
1
2
3
6. Result
Initial setting time of cement =
7. Questions
a. What do you understand by the term standard consistency, initial setting time and
final setting time of a cement sample?
b. What is the importance of the above three tests?
c. What is the difference between setting and hardening?

EXPERIMENT No. 3
Test Method for the determination of Soundness of cement
1. Scope
This test method covers the determination of soundness of cement.
2. Definition
Soundness of cement is the difference of the initial distance and final distance
between the indicator needles.
3. Apparatus
3.1 Le Chatelier apparatus
 The mould shall be of spring brass with indicator needles.
 A pair of plane glass base and cover plates shall be provided for each
mould.
3.2 Water-bath
 With means of heating capable of containing immersed Le Chatelier
specimens and of raising the temperature of the water from (20  2) oC
to boiling in (30  5) min.
3.3 Humidity cabinet
 Of adequate size and maintained at (20  1) oC and not less than 98%
relative humidity.
4. Procedure
4.1. Prepare a cement paste of standard consistence. Place a lightly oiled Le
Chatelier mould on the lightly oiled base-plate and fill it immediately with
out undue compaction or vibration using only the hands. During filling,
prevent, the split in the mould from accidentally opening by gentle pressure
with the fingers or by tying or by use of suitable rubber band.
4.2. Cover the mould with lightly oiled cover plate, add the additional mass and
then immediately place the complete apparatus in the humidity cabinet.
Maintain it for (24  0.5) h at (20  1) oC and not less than 98% relative
humidity.
4.3. At the end of the (24 0.5) h period measure the distance (A) between the
indicator points to the nearest 0.5mm. Then heat the mould gradually to
boiling during (30 5) min and maintain the water- bath at boiling temperature
for 3h  5min.
4.4. Allow the mould to cool to (20  2) oC. Measure the distance (B) between the
indicator points to the nearest 0.5mm.

5. Observation and calculation
OBSEVATION SHEET
SOUNDNESS OF CEMENT
Trial No Initial Distance b/n Final distance Soundness Average

the indicator needles between the Value Soundness
A (mm) indicator needles Value
B (mm)
Expansion of cement (B-A) _____mm
6. Result
Soundness of cement ________mm
7. Questions
What is meant by unsoundness and how it is caused?
What is likely to cause unsound cement?
What is the importance of soundness of cement?
What is the cause of free lime in cement?
Why is it necessary to keep the cement paste moist in this test?
What is the maximum expansion for ordinary Portland cement?

EXPERIMENT No. 4
Test Method for Specific Gravity and Absorption of Coarse Aggregate
1. Scope:
This test method covers the determination of specific gravity and absorption of coarse
aggregate. The specific gravity may be expressed as bulk specific gravity (SSD), or
apparent specific gravity. The bulk specific gravity and absorption are based on aggregate
after 24hr. soaking in water.
2. Definition
2.1 Absorption- the increase in the weight of aggregate due to water in the pore of the
material, but not including water adhering to the outside surface of the particles,
expressed as percentage of the dry weight. The aggregate is considered
“dry”when it has been maintained at a temperature of 105-115 oc for sufficient
time to remove all uncombined water.
2.2 Specific gravity- the ratio of the mass (or weight in air) of a unit volume of
material the mass of the same volume of water at stated temperature. Values are
dimensionless.
2.3 Apparent specific gravity- the ratio of the weight in air of unit volume of the
impermeable portion of the aggregate at a stated temperature to the weight in air
of an equal volume of gas free distilled water at a stated temperature.
2.4 Bulk specific gravity – the ratio of the weight in air of a unit volume of aggregate
(including the permeable and impermeable voids in the particles, but not
including the voids between particles) at a stated temperature to the weight in air
of equal volume of gas free distilled water at a stated temperature.
2.5 Bulk specific gravity (SSD) –the ratio of the weight in air of a unit volume of
aggregate, including the weight of water with in the voids filled to the extent
achieved by submerging in water for approximately 24 hr.(but not including the
voids between particles) at a stated temperature ,compared to the weight in air of
an equal volume of gas free distilled water at a stated temperature.
3. Apparatus-
3.1 Balance: - A weighing device that is sensitive, readable, and accurate 0.1% of the
sample weight.
3.2 Sample container: - A wire basket of 3.35mm or finer mesh, or a bucket of
approximately equal breadth and height.
3.3 Water tank: – A watertight tank in to which the sample container may be placed
while suspended below the balance.
4. Sampling
The minimum mass of test sample to be used is given as follows. Testing the coarse
aggregate in several sizes fraction is permitted. If the sample contains more than 155
retained on the 37.5mm sieve, test the material larger than 37.5mm in one or more size
fractions separately from the smaller size fractions, the minimum mass of the test sample
for each fraction shall be the difference between the masses prescribed for the maximum
and minimum sizes of the fraction.

Nominal Maximum size Minimum mass of test of sample (Kg)

12.5 2
19 3
25 4
37.5 5
50 8
63 12
75 18
90 25
100 40
125 75
5. Procedure
5.1 Dry the test sample to constant weight at a temperature of 105 – 150, cool in air at
room temperature for 1-3hours for test samples of 37.5mm nominal maximum
size, or longer for larger sizes until the aggregate in water at room temperature for
a period of 20 - 28hrs.
5.2 Where the absorption and specific gravity values are to be used in proportioning
concrete mixtures in which the aggregates will be in their naturally moist
condition, the requirement for initial drying may be eliminated.
5.3 Remove the test sample from the water and roll it in a large absorbent cloth until all
visible films of water removed. Wipe the larger particles individually. Take care
to avoid evaporation of water from aggregate pores during the surface dry
operation. Weigh the test sample in the saturated surface dry (SSD) condition.
Record this and all subsequent weights to the nearest 0.5gm.
5.4 After weighing, immediately place the SSD test sample in the container and
determine its weight in water at 21.3- 24.7 oc, having a density of 995-999 kg/m3.
Take care to remove all entrapped air before weighing by shaking the container
while immersed.
5.5 Dry the test sample to constant weight at a temperature of 105-115 oc, cool in air at
room temperature 1-3 hrs, or until the aggregate has cooled to a temperature that
is comfortable to handle, and weigh.

6. Calculations
6.1 Specific Gravity:
6.1.1 Bulk Specific Gravity – Calculate the bulk specific gravity, as follows:
Bulk sp. gr. = A/(B-C)
6.1.2 Bulk Specific Gravity (saturated surface dry) – Calculate the bulk specific gravity
(SSD), as follows
Bulk sp. gr. (SSD) = B/(B-C)
6.1.3 Apparent Specific Gravity – Calculate the apparent specific gravity as follows:
Apparent sp. gr. =A/(A-C)
Where:
A= Weight of oven dry sample in air
B= Weight of saturated -surface dry sample in air
C= Weight of saturated -surface dry sample in water
6.2 Absorption – Calculate the percentage of absorption as follows:
Absorption, %= (B-A)/A *100
7. Results
7.1 Bulk sp. gr. = _________
7.2 Bulk sp. gr. (SSD) = _________
7.3 Apparent sp. gr. =___________
7.4 Absorption, %= ____________
8. Questions
a. Does hardness affect specific gravity of an aggregate?
b. Why should we test coarse aggregate sample for absorption?
c. Why should we test the value of specific gravity of a coarse aggregate?
d. What are the limits for the values of specific gravity and absorption of good
aggregate?

EXPERIMENT No. 5
Test Method for Specific Gravity and Absorption of Fine Aggregate
1. Scope: - this test method covers the determination of bulk and apparent specific
gravity and absorption of fine aggregate.
2. Theory: -
 Bulk specific gravity: is the characteristic generally for the calculation for
the volume occupied by aggregate including Portland cement concrete,
bituminous concrete and other mixture that are proportioned or analyzed
on an absolute volume basis. It is also used in the computation of voids in
aggregate determination of moisture content in aggregate by displacement
in water method.
 Apparent specific gravity: pertains to the relative density of the solid
material making up the constituent particles not including the pore space
with in the particles that is accessible to water. This value is not widely
used in construction aggregate technology.
 Absorption: values are used to calculate the change in the weight of an
aggregate due to water absorbed in the pore spaces with in the constituent
particles, compare to the dry condition, when it is deemed that the
aggregate has been in contact with water long enough to satisfy most of
the absorption potential.
3. Apparatus:
 Balance
 Pycnometer: - a volumetric flask of 500 cm3 capacities or a fruit jar fitted
with a pycnometer top is satisfactory for a 500 gm test sample of
most fine aggregates.
 Mold: - a metal mold in the form of a frustum of cone with dimensions as
follows: 40+3mm inside diameter at the top, 90+3mm inside
diameter at the bottom, and 75+3mm in height, with the metal
having a minimum thickness of 0.8mm.
 Tamper: - a metal tamper weighing 340+15gm and having a flat circular
tamping face 25+3mm in diameter.
4. preparation of test sample: - dry the test sample in suitable pan to constant
temperature of 110+5oc. allow it to cool to comfortable handling
temperature, cover with water, either by emersion or by addition of at least
6% moisture to the fine aggregate and permit to sand for 24+4h.
5. procedure:
Partially fill the pycnometer with water, immediately introduce in to the
pycnometer 500 gm of saturated surface dry fine aggregate prepared as
described in section above, and fill with additional water to approximately
90% of capacity. If a weight other than 500gm is used, insert the actual
weight in place of figure “500” where ever it appears in the appropriate
formula. Roll, invert agitate the pycnometer to eliminate all air bubbles.
Adjust its temperature to 23+1.7oc, if necessary by immersion in circulating
water, and bring the water level in the pycnometer to its calibrated capacity.
Determine total weight of the pycnometer, specimen, and water. Record this
and all other weight to the nearest 0.1gm.

6. observation and calculation
6.1. Bulk specific gravity
Bulk sp. Gr. = A

(B + 500 – C)
6.2. Bulk specific gravity (saturated surface dry basis)
Bulk sp. Gr. (SSD) = 500

(B + 500 - C)
6.3. Apparent specific gravity
7.
8. g
9.

EXPERIMENT No. 6
Test Method for the determination of Moisture Content of Coarse Aggregate.
1. Scope
This is method covers the determination of moisture content of course aggregate
by oven-dry method.
This method is sufficiently accurate for usual purpose such as adjusting batch
weights of concrete. It will generally measure the moisture in the test sample more
reliably than the sample can be made to represent the aggregate supply.
2. Definition:
Moisture content is the total amount of water present in the aggregate. i.e. both
internally inside the pores and externally at the surface.
3. Apparatus:
3.1 Balance of suitable capacity, readable and accurate.
3.2 Containers, airtight, non-corrodible, of capacity suitable to the mass of the test
portion.
3.3 Well ventilated oven, thermostatically controlled to maintain a temperature
of 105  50c.
3.4. Means of reducing the laboratory sample, either metal tray for use in
quartering or a riffle box.
4. Procedure:
4.1 Clean a container, dry it and then weigh it (M1). Place the test portion prepared
to the container and reweigh the whole (M2).
4.2 Place the container and test portion in the oven and dry at a temperature 105
50c. Maintaining this temperature until the test portion has reached a constant
mass (Normally 16hr to 24hr is sufficient period).
4.3 Remove the container and test portion from the oven and allow the whole to
cool for 0.5hr to 1hr, after which weigh again (M3).
4.4. Carry out and record all weightings to an accuracy of 0.1gm.

5. Sampling
Sample size for Nominal-weight aggregate
Nominal size (mm) Weight of sample (Kg)
6.3 0.5
9.5 1.5
12.5 2
19 3
25 4
37.5 6
50 8
63 10
75 13
6. Observation and Calculation
Calculate the moisture content as a percentage of the dry mass from the following
equation.
(M 2  M 3)
Moisture content  x 100
(M 3  M 1)
Where:
M1 – is the mass of dry container in gm.
M2 – is the mass of container and wet test portion in gm.
M3 – is the mass of container and dry test portion in gm.
OBSERVATION SHEET
MOISTURE CONTENT OF AGGREGATE
S.No Container Weight of Weight of Weigh of Moisture Average
Number Container Container + Container + dry Content Moisture
wet test portion test portion in in % Content
in gm gm in %
1
2
Result: Moisture Content =

6. Questions:
1. State the different state in which the aggregate exists?
2. What is the difference between free moisture and absorbed moisture?
3. What is the significance of determining moisture content of aggregates?

EXPERIMENT No. 7
Test Method for Particle Size Distribution & Fineness Modules of Aggregates.
1. Scope
This test method covers the determination of particle size distribution of fine, coarse
and all- in aggregates by sieving.
2. Definition
Aggregates most of, which passes BS 5.00mm sieve is classified as fine aggregate on
the other hand aggregates most of which is retained on BS 5.00mm sieve is classified as
coarse aggregate.
3. Apparatus
3.1 Balance – The balance or scale shall be such that it is readable and accurate to
0.1% of the weight of the sample.
3.2 Sieves – Sieves of the size shown in table 1.1 and 1.2 conforming to BS.
4. Sampling
Fine aggregate: - the size of the test sample, after drying shall be 300gm minimum.
Coarse Aggregate:- the size of the test sample of coarse aggregate shall be conform
with the following:
Nominal maximum size Test sample size minimum

square opening (mm) (Kg)
9.5 1
12 2
19 5
25 10
37.5 15
50 20
63 35
75 60
90 100
100 150
125 300

5. Procedure
5.1 The sample shall be brought to an air-dry condition before weighing and sieving.
The air-dry sample shall be weighed and sieved and sieved successively on the
appropriate sieves starting with the largest size sieve. Care shall be taken to
ensure that the sieves are clean before use.
5.2 If sieving is carried out with a nest of sieves on a sieve shaker the nest of sieves
shall be shaken for a period, not less than 10min. But if not each sieve shall be
shaken separately over a clean tray for a period of not less than 2min

Table 1.1 Sieve Analysis of Coarse Aggregate
Date of testing _____________
Weight of sample taken __________(gm)
BS Weight of
% Cumulative
Sieve Weight of sieve + Weight
Weight % Wt. % Passing
size in sieve in gm sample in retained
retained retained
mm gm
37.5
28.0*
20.0
14.0*
10.0
5.00
2.36
Pan
C=
Fineness Modules of coarse aggregate = C /100
Note: - * indicates intermediate sieve
Table 1.2 Sieve Analysis of Fine Aggregate

Date of testing _____________
Weight of sample taken __________(gm)
BS
Weight of Weight % Cumulative
Sieve Weight of sieve + retained Weight % Wt. % Passing
size in sieve ( gm)
sample ( gm) (gm) retained retained
mm
5.00
2.36
1.18
0.710
0.355
0.180
0.075
Pan
C=
Fineness Modules of fine aggregate = C /100

7. Questions
a. Define fineness modules of an aggregate and what is its importance?
b. What is the significance of grading of aggregate and what is meant by good
grading?
c. How should aggregate be stockpiled on a construction site?
d. Differentiate between fine, coarse and mixed aggregate?
e.The fineness modules of sand should lie in what range of limits?
f. How does the size of an aggregate affect its fineness modules?
g. What is a grading curve and where it is used?

EXPERIMENT No. 8
Test Method for the determination of Organic Impurities for Fine Aggregate.
1. Object:-
To test the fine aggregate for organic impurities.
2. Theory:-
The aggregate must be checked for organic impurities such as decayed vegetation,
humus, coal dust, etc. Color test is a reliable indicator of the presence of harmful organic
matter in aggregates except in areas where there are deposits of lignite.
3. Procedure:
3.1 Fill a 350 ml clear glass medicine bottle up to 75ml mark with a 3% solution of
caustic soda or sodium hydroxide. A 3% solution of caustic soda is made by
dissolving 3gn of sodium hydroxide (which can be purchased from any chemist)
in 100ml of water preferably distilled. The solution should be kept in glass bottle
tightly closed with a rubber stopper. Handling sodium hydroxide with moist hands
may result in serious burns. Care should be taken not to spill the solution for it is
highly injurious to clothing, leather and other materials.
3.2 The sand is next added gradually until the volume measured by the sandy layer is
125ml. The volume is then made up to 200 ml by the addition of more of the
solution. The bottle is then crocked and shaken vigorously and allowed to stand
for 24 hours.
3.3 At the end of this period, the color of the liquid will indicate whether the sand
contains a dangerous amount of matter. A colorless liquid indicates clean sand
free from organic matter. A straw-colored solution indicates some organic matter
but not enough to be seriously objectionable. Darker color means that the sand
contains injurious amounts and should not be used unless it is washed, and a re-
test then shows that is satisfactory.
Note: the acids in the sample are neutralized by a 3% solution of NaOH,
prescribed quantities of aggregate and of solution being placed in a bottle. The
mixture is vigorously taken to allow the intimate contact necessary for chemical
reaction, and then left to sand for 24 hours and then the organic contact can be
judged by color.

4. Observation:
Color of the liquid observed = Colorless / straw color / darker color.
5. Precautions:
a) Use every possible care while handling sodium hydroxide solution.
b) The sand and the sodium hydroxide should be shaken vigorously to get good
results.
6. Comments:
Give your comments on the color of the liquid. Do you recommend this sand for
civil Engineering Construction?
7. Questions:
a) What do you understand by organic impurities in aggregates?
b) Does this impurity occur in fine or coarse aggregate or in both?
c) Under what color of liquid the organic impurity is ascertained in aggregate?
d) What effect will dirty aggregates have no the strength have no the strength of the
concrete.

EXPERIMENT No. 9
Test Method for the determination of Silt Content of Fine Aggregate.
1. Object-
To determine the silt content of a fine aggregate sample.
2. Theory-
It is important to use clean aggregate for concrete. If the aggregates are coated with
dirt, silt or clay, it will result in a poor concrete because the dirt will prevent the cement
from setting and also weaken the bond between the aggregates and the cement paste.
In the hand test, simply pick up a little sample of sand and rub it between your hands.
If your palm stays clean the sand is alright from the cleanliness point of view. If it
stained, something is wrong and you must proceed to perform the silt test.
3. Apparatus-
Measuring cylinder of 200 cc capacity, Salt (NaoH)
4. Procedure:
a) Fill a measuring cylinder with sand up to 100 cc mark and add water up to
150cc. To perform this test, more correctly better dissolve a little salt in the
water (1 test spoonful to 250cc is the right proportion).
b) Shake the sample vigorously for one minute and the last few shakes being in
a side wise direction to level off the sand.
c) Allow The cylinder to stand for three hours during which time any silt
present will settle in a layer on the top of the sand and its thickness can be
read off on the cylinder itself. There should not be more than 6cc of silt or
about 6 to 10 percent of the amount of the sand.
5. Result:
Silt Content
6. Precautions:
a) Shaking of the sample should be upside down and sidewise so that water
reaches every location of the sample.
b) Perform the experiment away from shocks and vibrations.
7. Questions:
a) State the importance of this test.
b) What is the upper limit of silt content of a sand sample
c) What is the effect of excessive silt content on the strength of concrete
containing this sand?
d) Comment on the suitability of the sand sample for use on a construction site.
If the sample is not suitable for use, suggest the measures to be taken.

EXPERIMENT No.10
Test Method for the determination of Bulk Density and percentage Voids in
aggregate.
1. Scope
To determine the bulk density and percentage void in aggregate.
2. Theory
Unit weight (Bulk Density) is the weight of a unit volume of aggregate usually
stated in Kg/m3. In estimating quantities of materials and in concrete mix proportioning,
when bathing is done on a volumetric basis, it is necessary to know the conditions under
which the aggregate volume is to be measured namely:
a) Loose or compacted and
b) Dry or damp.
For scheduling volumetric batch quantities, the unit weight in loose, damp state should be
known. With respect to a mass of aggregate the term "voids" refers to the spaces between
the aggregate particles. Numerically this void space is the difference between the gross or
over all volume of the aggregate mass and the space occupied by the aggregate particles
alone.
3. Apparatus
3.1. Cylinderical metal container, as given in table 1
3.2. Balance, accurate to 0.2 % of the mass of the material to be weighed and
adequate capacity.
3.3. Straight metal tamping rod, of circular cross section, 16 mm in diameter
600mm long.
4. Calibration
 Fill the measure with water at room temperature and cover with apiece of
plate glass in such a way as eliminate bubbles and excess water.
 Determine the net weight of water in the measure to an accuracy of +0.1%
 Measure the temperature of water and determine its unite weight from
table 2, interpolating if necessary.
 Calculate the factor for the measure by dividing the unite weight of the
water by the weight required to fill the measure.
5. Condition of sample
The test for bulk density shall be made on oven dry or saturated surface dry
material. The test for voids shall be made on oven dry material. The test for bulking shall
be made initially on oven dry material and then at the required test moisture content.

6. Procedure
6.1. Compacted Bulk Density
Fill the container about one third full with the thourouly mixed aggregate by
means of a shovel or scoop, the aggregate being discharged from a height not
exceeding 50mm above the top of the container. Take care to prevent so far as is
possible, segregation of the particle sizes of which the sample is composed. Then give
the required number of comp active blows (see table 1) to the aggregate, each blow
being given by allowing the tamping rod to fall freely from a height 50 mm above the
surface of the aggregate, the blows being evenly distributed over the surface. Add a
further similar quantity of aggregate in the same manner and give the same number of
blows. Fill the container to over flowing, tamp it again with the same number of
blows, and remove the surplus aggregate by rolling the tamping rod across and in
contact with the top of the container, any aggregate which impedes its progress being
removed by hand, and add the aggregate to fill any obvious depressions. Then
determine the mass of the aggregate in the container. Make two tests and calculate the
bulk density in kilogram per cubic meter using the calibrated volume from the mean
of the two masses.
6.2. UnCompacted Bulk Density
To determine the loose mass (uncompacted bulk density) carry out the test as
described in 6.1 except that the compaction with the tamping rod shall be omitted.

In this test voids are expressed as a percentage of the volume of the test cylinder.
They are determined from the difference between the volume of the test cylinder and
the calculated volume of the aggregate.
The percentage of voids is given by the formula:
100 * a-b /a
Where:
a- is the particle density of the aggregate on an oven dry basis.
b-is the bulk density of oven dry aggregate.
OBSERVATION SHEET
BULK DENSITY AND PERCENTAGE OF VOIDS FOR COARSE AGGREGATE
No Calibrated Weight of Weight of Weight of Bulk Average Sp.gr Void Average Void
volume of container container aggregate density Bulk oven percentage percentage
container plus (Kg/m3) density dry
aggregate (Kg/m3) state
1
2

OBSERVATION SHEET
BULK DENSITY AND PERCENTAGE OF VOIDS FOR FINE AGGREGATE

No Calibrated Weight of Weight of Weight of Bulk Average Sp.gr Void Average Void
volume of container container aggregate density Bulk oven percentage percentage
container plus (Kg/m3) density dry
aggregate (Kg/m3) state
1
2
Table 1. Details of Containers to be used for the bulk density tests

Nominal Internal diameter Internal depth Compacted bulk density Uncompacted
(approximate) bulk density
volume (approximate)
Nominal Number of Nominal size of
size of comparativ aggregate up to
aggregate e blows per and including
up to and layer
including:
m3 mm mm mm mm
0.03 350 300 50 100 50
0.015 250 300 28 50 14
2)
0.01 200 320 20 40 20
0.007 200 225 14 30 6
0.003 150 150 6 20 -
Table 2. Unite weight of water

Temprature Unit weight
0 0
F C Lb/ft3 Kg/m3
60 15.6 62.366 999.01
65 18.3 62.336 998.54
70 21.1 62.301 997.97
73.4 23.0 62.274 997.54
75 23.9 62.261 997.32
80 26.7 62.216 996.59
85 29.4 62.166 995.83
8. Question:
a) What do you understand by voids in aggregates?
b) What is the importance of voids in aggregates and what are their limits for
good aggregate.
c) What are the factors that will affect bulk density of aggregate?

EXPERIMENT No. 11
Test Method for the Consistency of Freshly Mixed Concrete by Slump test.
1. Scope
This test method covers the determination of the consistency of fresh concrete of
given proportions by slump test where the nominal size of the aggregate does not
exceed 38mm.
2. Definition
Fresh un- supported concrete flows to the sides and the sinking in the height takes
place. This vertical settlement is known as slump. The slump test does not measure the
workability of concrete, however it is very useful in detecting the variation in the
uniformity of given nominal proportions. It gives an idea of W/C ratio needed for
concrete to be used for different works.
3. Apparatus
3.1 Mould – The mold for the test specimen shall be in the form of frustum of a cone
having the following internal dimensions:
Bottom diameter = 200mm, Top diameter = 100mm & Height = 300mm
3.2 Tamping rod –The tamping rod shall be of steel or other suitable material 16mm
in diameter, 600mm long and rounded at one end.
4. Procedure
4.1 The internal surface of the mould shall be thoroughly cleaned and freed from
moisture and any set concrete before commencing the test. The mould shall be
placed on a smooth, horizontal, rigid and non-absorbent surface.
4.2 The mould shall be filled in four layers, each approximately one-third quarter of
the height of the mould. Each layer shall be tamped with twenty-five strokes of
the tamping rod. The bottom layer shall be tamped throughout its depth.
4.3 After the top layer has been rodded, the concrete shall be struck off level with a
trowel or the tamping rod, so that the mould is exactly filled.
4.4 The mould shall be removed from the concrete immediately by raising it slowly
and carefully in a vertical direction.
5. Observations
Trial Water cement
Slump (mm)
No. ratio W/C
1
2
5. Questions
a. State the significance of the slump test
b. Differentiate by sketches the term true slump, shear and collapse type of slumps.
c. Define workability and consistency of freshly mixed concrete.

EXPERIMENT No. 12
Test Method for the Consistency of Freshly Mixed Concrete by Compaction Factor
test.
1. Scope
This test method covers the determination of the consistency of freshly mixed
concrete by compaction factor test.
2. Definition
The compacting factor is defined as the ratio of the weight of partially compacted
concrete to the weight of fully compacted concrete. Compaction factor test specifies the
procedure for determining the workability of concrete, where the nominal size of the
aggregate does not exceed 38mm.This test is based upon the definition, that workability
is that property of concrete, which determines the amount of work, required to produce
full compaction.
3. Apparatus
3.1 Compaction factor apparatus
3.2 Tamping rod and balance.
4. Procedure
4.1 The sample of concrete to be tested shall be placed gently in the upper hopper.
The hopper shall be filled to its brim and the trap door shall be opened so that
the concrete falls in to the lower hopper. Certain mixes may have the tendency
to stick in one or both the hoppers. If this occurs, the concrete may be helped
through by pushing the rod gently into the concrete from the top.
4.2 Immediately after the concrete has come to rest, the cylinder shall be covered and
the trap door of the lower hopper opened and the concrete allowed falling into
the cylinder. The excess concrete remaining above the level of the top of the
cylinder shall then be cut off by using a trowel. The outside of the cylinder shall
then be wiped clear.
4.3 The weight of concrete in the cylinder shall then be determined to the nearest
(1gm) (W2). This weight shall be known as the weight of partially compacted
concrete.
4.4 The cylinder shall be refilled with concrete from the same sample to layers
approximately 50mm deep, the layers being heavily rammed or preferably
vibrated so as to obtain full compaction. The top surface of the fully compacted
concrete shall be carefully struck off level with the top of the cylinder. The
outside of the cylinder shall then be wiped clear and weight of fully compacted
cylinder noted nearest to (1gm) (W1).

5. Observation and calculation

OBSERVATION SHEET
COMPACTION FACTOR OF FRESH CONCRETE

Trial Weight of partially Weight of fully Compaction
No compacted concrete(W1) compacted concrete(W2) Factor value
1
2
The value of compaction factor can be calculated as follows:
W1
Cmpactionfactor 
W2
6. Questions:
(a) Define compaction factor.
(b) How do you compare slump test with compaction factor test?
(c) Will the workability increase or decrease with increase in compaction factor
and why?
(d) Differentiate between workability and consistency.

EXPERIMENT No. 13
Rapid Analysis of Freshly Mixed concrete (RAM).
1. Scope
This test covers the rapid determination of cement and silt content of freshly
mixed concrete.
2. Definition.
The term "silt" as used in connection with the RAM test is defined as any non-
cemetitious materials passing a 150 micron sieve.
3. Apparatus.
RAM
4. Procedure.
4. 1. 750 gram and 1500 gram cement contents.

i. Weigh out the required amount of cement (750 or 1500 grams) into a
container.
ii. Add the cement to approximately 7 kg of clean washed aggregate, add
sufficient water to produce a workable concrete mix, and mix
thoroughly.
iii. Carry out a normal RAM test using this mix, and record the result.
iv. Repeat operations I, II and III re-using the clean aggregate collected
from the dump valve unit all 6 reading are obtained.
4.2. Zero cement content

i. Carry out a test, using approximately 7kg of clean aggregate only, do
not place any cement in the sample.
ii. Weigh the constant volume vessel and its contents, and record the
reading.
iii. Repeat operations (II) and (III) above until the required 5 sets of
Weights are obtained.
5. Calibration of cement
5.1. Find the average weight of the CVV and its contents for each value of
cement content ( i.e. for 0, 750 gm and 1500rm).
5.2. Using the weight of CVV on the vertical axis against the known cement
content on the horizontal axis, Plot the three average values obtained in 5.1.
* The calibration line is the line, which joins the 750gm point with
1500gm point

RAM CALIBRATION LINE
RAM NO. _______________ Location ______________
RAM Operator __________ Date _______________
Weight of CVV + Contents
Cement in sample (g) 0 750 1500

1
2
3
Mean value
Range
6. Calibration & Variability

For any group of 3 readings obtained in a calibration, the variability readings in
the group must be less than:
Cement Content 0gm 750gm 1500gm

Weight of constant volume vessel 2.0gm 3.5gm 5.0gm
and contents ( range of 3 results)
7. Determination of Silt Content.

7.1. Using representative sample of cement and aggregate, make up a test
specimen containing exactly 1000 grams of cement.
The corresponding amounts of fine and coarse aggregate should comply with the normal
mix proportions of the concrete to be tested. For example a nominal 1:2:4 mix would
contain:
1000gm cement, 2000gm sand, and 4000gm aggregate

Using sufficient water to give a workable mix.
7.2. Weigh test specimen.
7.3. Load the machine and carry out RAM analysis.
7.4. On completion of the test, remove and weigh the constant volume vessel
plus contents.
7.5. From the calibration graph, determine reading A (gram).

This value corresponds to 1000gm of cement plus silt from the aggregates.
The silt content collected, S to:
S  Re adiungA 1000 grams

and
S
Dx  SiltContent (kg / m3 ).
Weight of test specimen
Where D is the wet density of the concrete in kg/m3.
7.6. Repeat the test to obtain five results.
The range of the five results should not exceed 20kg/m3.The average of the five
results is the silt Content Value (kg/m3).
7.7. The cement content (kg/m3) of a sample is then found by

Measured Cement Content – Silt Content Value + True Cement Content.
7.8. The Silt content value should be checked at regular intervals, say one test per
week for a machine in constant use. If the difference between this result and
the established value is more than 15kg/m3 anew silt content value based on
five results should be determined.
Whenever the concreting materials are changed a new silt content value
should be established.
7.9. A worked example showing how to calculate the silt content value is shown
on the next page.

RAM SILT CONTENT VALUE
RAM No ______________________ Location ________________

RAM Operator _________________ Date ___________________
Mix Proportions
Material Dry Wet weight Test mix (g)

weight kg/m3
kg/m3
Aggregate 20mm
10mm
Sand
Cement
Water
Total (D)= (W)=
Silt Contents kg/m3

Weight of CVV+ A
contents ( from calibration S = A – 1000G S xD
graph) W
Mean ____________________
Range ____________________

EXPERIMENT No. 14
Test Method for the determination of compressive strength of concrete.
1. Scope:
To determine the cube strength and cylinder strength of concrete of given
proportions say 1:2:4 by weight and W/C = 0.6 by weight.
2. Theory:
The compressive strength of concrete is one of its most important and useful
properties of concrete. In most structural applications, concrete is employed primarily to
resist compressive stresses. The compressive strength is used as a measure of overall
quality of the concrete.
3. Apparatus:
Cube moulds 150 mm is size, Cylinder moulds 150-mm diameter and 300 mm in
height, weighing machine, mixer, tamping rods, compression testing machine.
(a) Moulds for cube Test: These should be of steel or cast iron. The internal faces
should be machined flat to a tolerance of  0.025 mm. All interior angles
between internal faces should be 90  0.50. A base plate with machined plane
surface, large enough to prevent leakage of cement slurry during filling of the
mould should be provided. Spring clips or screws should be supplied to assist in
holding the mould on the base plate.
(b) Moulds for cylinder test: The standard size of test cylinder is 300 mm in height at
150 mm in diameter. These moulds are of cast iron.
(c ) Tamping Rod: It is 16 mm diameter steel rod, 600 mm in length and bullet nosed
at one end.
4. Procedure:
(a) Weigh the following quantities of ingredients:
For three cubes
Cement ---------------------------
Coarse Aggregate---------------
Sand-------------------------------
Water------------------------------
Mix them thoroughly in the mechanical mixer until uniform color is obtained.
This material will be sufficient for casting of 3 cubes of the size 150 mm x 150
mm The concrete may also be mixed by hand in such a manner as to avoid loss of
water. In mixing by hand the cement and fine aggregate shall be first mixed dry to

uniform color and then the coarse aggregate is added and mixed until the coarse
aggregate is uniformly distributed throughout the batch. Now the water shall be
added and whole is mixed until the resulting concrete is uniform in color (mix
atleast for two minutes).
(b) Pour the concrete so prepared in the moulds, which have been oiled with
medium viscosity oil. Fill concrete in cube moulds in three layers and cylinder
moulds in six layers each of approximately 50 mm and ramming each layer as
follows:
i) 150 mm cube:
Each layer to be tamped more than 35 times.
ii) 150 x 300 mm cylinder:
Each layer to be tamped more than 30 times over the surface, the
blows shall be evenly distributed to the layer.
iii) In place of hand ramming suitable vibrators may be used.
C) Trowel off surplus concrete from the top of moulds.
D) Cover the moulds with wet mats and mark them after about 3 to 4 hours.
E) Curing of specimen’s:
i) Specimens are removed from the moulds after 24 hours and cube
specimens cured in water for another 27 days.
5. Testing of Specimens:
Compression test of cube and cylindrical specimens are made as soon as
practicable after removing from curing tank. Test specimens during the period of their
removal from the curing pit and testing are kept moist by a wet mat covering and tested
in moist condition. The size of the specimens is determined to the nearest 0.2 mm by
averaging the particular dimensions, at least at two places. The length of the cylinder
including caps is measured to the nearest 0.2mm, The weight of each specimen is also
recorded.
Place central the specimen in the compression-testing machine and load is applied
continuously, uniformly and without shock. The load is increased until the specimen
fails. Record the maximum load taken by each specimen during test. Also note the type
of failure and appearance of cracks.

6. Observations and Calculations:

The following information is normally included in the report of each compression
test.
Table 1
A Identification mark
B Date of casting
C Date of testing
D Age of Specimen
E Curing Condition
F Dimensions of specimen
G Weight of specimen
H Cross sectional area
I Maximum load
J Compressive strength
k Appearance of fractured faces of concrete and type of
fracture
Table 2
Specimen No. 1 2 3 Average
Load in Newton on Cube
Load in Newton on cylinder
Average Load
(a ) Cube strength 
Area of cross  sec tion of cube specimen
Average Load
(b)Cylinder strength 
Area of cross  sec tion of cylinder specimen

9. Question:
(a) State the importance of compressive strength test.

(b) State the nature of compression failures observed by you during testing.
(c) What is permissible variation in strength of a specimen while taking the
average?
(d) The cubes should be tested on sides and not along the direction of casting
comment on this statement?
(e) In what respect cubes are better than cylindrical specimens?
(f) State the effect on compressive strength of (a) Size of specimen (b)
Slenderness (c) rate of leading.
(g) State the relationship between cube strength and cylinder strength?

EXPERIMENT No. 15
MIX DESIGHN OF CONCRETE
ACI Method
Like all other present day methods, the ACI method of proportioning is empirical in the
sense that it depends on data tabulated from observation of a large number of trial
mixtures bearing in mind that the selection of concrete proportions involves a balance
between reasonable economy and requirements for place ability. Strength and durability.
The use of the method, for estimating the required batch weigh for a concrete mix,
involves the following steps:
1. Scope
Estimating the required batch weigh for a concrete mix.
2. Procedures
Step 1. Choice of slump: If slump is not specified, recommended consistencies in terms
of slump for concerts consolidated by vibration are given in Table 8.21. The
method recommends using mixes of the stiffest consistency that can be placed
efficiently.
Step 2. Choice of Maximum size of aggregate: Recognizing the relationship between the
maximum size of an aggregate sample and its water – requirement factor as well
as its voids content, the method recommends using the largest size that is
economically available and consistent with dimensions of the structure. (The
maximum size should not exceed one-fifth the depth of slabs, nor three-fourths of
the minimum clear spacing between individual reinforcing bars, bundles of bars,
or pretentioning strands). The fineness modulus of the selected sand, the unit
weight of dry-rodded coarse aggregates are determined by test.
Step 3. Estimation of mixing water and air content: After selecting consistency and
aggregate size, the first toward selecting the proportions of cement, aggregate, air
and water is to estimate the water content. This is done by reading the total free
water (liters) per cubic meter of concrete from table 8.22 answering the table with
the selected slump and selected maximum size of aggregates. This is based on the
fact that the quantity of water per unit volume of concrete required to produce
desired consistency ( i.e. slump) is dependent on the maximum size, particles
shape and grading of the aggregates, and also on the fact that, for a given
maximum size of aggregate, the water content per unit volume of concrete
determines the workability of mix, largely independently of the mix proportions ,
or in other wards, the quantity of water per unit volume of concrete will be the
same at a given consistency and maximum size, independent of the cement
content.

Table 8.22 gives also the approximate amount of accidentally entrapped air in non-air-
entrained concrete as well as the recommended average total air content of air entrained
concrete.
Step 4. Selection of water/cement ratio: The water/cement ratio is selected from Table
8.23 based on the requirements for strength. However of durability may being into
consideration the permeability of the hardened cement paste, which content the
rate of penetration of water and impervious solutes. Because the coefficient of
permeability is higher the higher the water/ cement ratio of the paste and because
under some condition a very low coefficient of permeability is required, two
control of permeability rather than the permissible water/cement ratio. In such
cases the recommended limits on the water/ cement ratios are given in Table 8.24.
Step 5. Calculation of cement content: The amount of cement per unit value of concrete
is fixed by the determinations made in step and 4 above. The required cement is
equal to the estimated mixing water content (step 3) divided by the water/cement
ratio (step 4). If, however, the specification includes a separate minimum limit on
cement in addition to requirements for strength and durability, the mixture must
be used on whichever criterion leads to the larger amount of cement.
Step 6. Estimation of coarse aggregate content: The quantity of coarse aggregate per unit
volume of concrete on dry –roded basis is read in Table 8.25 against its maximum
size and the finesse modulus of sand. This is based on the knowledge that, for
equal workability, the volume of coarse aggregate in a unit volume of concrete is
dependent only on its maximum size and the grading of fine aggregate.
Differences in the amount of mortar required for workability with different
aggregates, due to differences in particle shape and grading, are compensated for
automatically by differences in dry-rodded void content. The volume so obtained
is converted to dry weight of coarse aggregate required per cubic meter of
concrete by multiplying it by the dry-rodded unit weight of the aggregate in
kilogrammes per cubic meter.
Step 7. Estimation of fine aggregate content: At completion of step 6, all ingredients of

the concrete have been estimated except the fine aggregate. Its quantity is
employed: the “weight" method or the “absolute" method.
If the weight of the concrete per unit volume is assumed or can be estimated
from experience, the required weight of fine aggregate is simply the difference
between the weight of fresh concrete and the total weight of the other ingredients.
Often the unit weight of concrete is known with reasonable accuracy from previous
experience with the materials. In the absence of such information, Table 8.26 can be
used to make a first estimate. Even if the estimate of concrete weight per cubic
meter in rough, mixture proportions will be sufficiently accurate to permit easy
adjustment on the basis of trial batches as well be shown in the examples.

Amore exact procedure for calculating the required amount of fine aggregate involves
the use of volumes displaced by the ingredients. In this case, absolute volume method,
the total volume displaced by the known ingredients- water, air, cement, and coarse
aggregate – is subtracted from the unit volume of concrete to obtain the required volume
of fine aggregate. The volume occupied in concrete by any ingredient is equal to its
weight divided by the density of that material.
Step 8. Adjustments for aggregate moisture: The aggregate quantities actually to be

weighed out for the concrete must allow for moisture in the aggregates.
Generally, the aggregates will be moist and their dry weights should be
increased by the percentage of water they contain, both absorbed and surface.
The mixing water added to the batch must be reduced by an amount equal to the
free moisture contributed by the aggregate – i.e., total moisture minus
absorption.
Step 9. Trial batch adjustment: The calculated mixture proportions should be checked by
means of trial batches prepared and tested in accordance with ASTMC 192,”
Making and Curing Concrete compression and Flexure Test Specimens in the
Laboratory".
Of full-sized field batches. Only sufficient water should be used to produce
the required slump regardless of the amount assumed in selecting the trial
proportions. The concrete should be checked for unit weight and yield (ASTM C
!#*) (81) and for air be carefully observes for proper workability, freedom from
segregation, and finishing properties. Appropriate adjustments should be made in
the proportions for subsequent batches.

The above procedure in short

1. Data to be collected
i. Fines modulus of selected FA
ii. Unite weight of dry roadbed CA
iii. Sp.gr of CA and FA
iv. Absorption characteristics of both CA and FA
v. Sp.gr of cement (approximately, 3.15)
2. From the minimum strength specified, estimate the average design strength
(table 8.27)
3. Specify the minimum cement content (table 8.27).
4. Choice of slump ( from Table 8.21 or Table 8.28)
5. Determine maximum size of CA.
6. Estimate mixing water, and air content ( from table 8.22)
7. Select W/C (from table 8.23) based on strength or (from table 8.24) based on
requirement for durability.
8. Calculate the cement content and compare with step 3, and take whatever is
larger.
9. Estimate the bulk volume of dry raided as per unit volume of concrete(table 8.25)
10. Calculate wt. of CA per M3of concrete,
Wt. of CA=bulk volume X Bulk density
11. Calculate the solid volume of CA in 1m3 of concrete
Solid volume of CA= Wt. of CA / 1000 x Sp.g
12. Similarly the solid volume of cement / water and volume of air is calculated in
1m3.
13. Solid volume of sand is then calculated by subtracting from the data volume of
concrete per unit volume is the solid volume of cement, CA, water and entrapped
air or if the weight of the concrete per unit volume is assumed or can be estimated
from experience (table 8.26), the rigged weight of FA is the difference between
the weight of fresh one and the total weight of the ingredients.
14. Adjustments for aggregate moisture
15. Trial batch adjustments. The calculated mix proportion should be checked by
means of trial batch.

TABLES FOR ACI CONCRETE MIX DESIN
Table 8.23 Estimated Average Strength for Concrete
Compressive strength Water / cement ratio (by mass)

28 days (M pa)
Non-air entrained Air entrained
45 0.38 -
40 0.42 -
35 0.47 0.39
30 0.54 0.45
25 0.61 0.52
20 0.69 0.60
15 0.79 0.71
*Values are estimated average strength for concrete containing not more than percentage of air shown in
table 3. For constant water/cement ratio, the strength of concrete is reduced as the air content is measured.
Strength is based on 15x30cm cylinders moist-cured 28 days at 25+ 1.7 oC in accordance with section
9(b) of ASTM C31 for making and curing concrete compressive and flexure test specimen in the field.
Cube strength will be higher by approximately 20oC.
Relationship assume size of aggregate about 20 to 30mm, for a given source, strength produced by a given
water/cement ratio will increase as maximum size decrease.
Table 2. Fine aggregate as a percentage of total aggregate
Max. agg. size Fineness modulus

W/c (mm) 2.5 2.7 2.9
10 50% 52% 54%
0.4 20 35 37 39
40 29 31 33
10 53 55 57
0.5 20 38 40 42
40 32 34 36
10 54 56 58
0.6 20 40 42 44
40 33 35 37
10 55 57 59
0.7 20 41 43 45
40 34 36 38

Table 8.21 Recommended slumps for various types of constructions
Slump (cm)
Types of construction
*Max. Min.
Reinforced foundations, walls and footings 8 2
Plain footings, cassoins and substructure walls 8 2
Beams and reinforced walls 10 2
Building columns 10 2
Pavements and slabs 8 2
Heavy mass concrete 8 2
* may be increased by 2cm for methods of consolidation other than vibration
Table 8.22 Approximate mixing water requirements for different slumps and maximum
sizes of aggregates.
Slump (cm) Water kg/m3 of concrete for indicated max. sizes of agg. in mm *
10 12.5 20 25 40 50+ 70+ 150+
Non –Air entrained concrete
3- 5 205 200 185 180 160 155 145 125
8- 10 225 215 200 195 175 170 160 140
15-18 240 230 210 205 185 180 170 --
Approx. amount of
entrapped air in non 3 25 2 15 1 0.5 0.3 0.2
entrained concrete (%)
Air entrained concrete
3 to 5 180 175 165 160 145 140 135 120
8 to 10 215 205 190 185 170 165 160 --
Recommended average
total air content (%) 8 7 6 5 4.5 4 3.5 3
* These quantities of mixing water for use in computing cement factors for trial batches. They are maxima
for reasonably well shaped angular course agg graded with in limit of accepted specifications.
+
The slump values for concrete containing agg larger than 40mm are based on slump tests after removal of
larger than 40mm by wet screening.

Table 8.24 Maximum permissible water cement ratios for concrete in severe
Exposure
Structure wet continuously or frequently Structure exposed to sea
Type of structure and exposed to freezing and thawing water or surfaces
Thin sections (railing

curbs, sills, ledges,
ornamental work) and
sections with less than 0.45 0.40
3cm cover over steel
All other structures 0.50 0.45
* Based on the report on ACI committee 201 “Durability of concrete in severe previously cited concrete
should also be air entrained”
 If sulphate-resisting cement (type II or Type V of ASTMC 150) is used permissibly water-cement ratio
may be increased by 0.50.
Table 8.25 Volume of coarse Aggregate per unit Volume of concrete
Volume of dry rodded coarse aggregate per unit volume of concrete for different
Maximum size of fineness modulus
aggregate 2.4 2.6 2.8 3.0
10 0.50 0.50 0.46 0.44
12.5 0.59 0.59 0.55 0.53
20 0.66 0.66 0.62 0.60
25 0.71 0.71 0.67 0.65
40 0.76 0.76 0.72 0.70
50 0.78 0.78 0.74 0.72
70 0.81 0.81 0.77 0.75
150 0.87 0.87 0.83 0.81
 Volumes are based on aggregate in dry rodded condition as described in ASTEC29 for unit weight
of aggregate.
These volumes are selected empirical relationship to produce concrete with a degree of workability
suitable for usual reinforced construction. For less workable concrete such as required for pavement
construction they may be increased about 10%. For more workable concrete, such as required may be
required when placement is to be by pumping, they may be reduced up to10%.

Table 8.26 First Estimate of Weight of Fresh Concrete.
Maximum size of aggregate, First estimate of concrete weight, Kg/m3

mm Non-air entrained concrete Air- entrained concrete
10 2285 2190
12.5 2315 2235
20 2355 2280
25 2375 2315
40 2420 2355
50 2445 2375
70 2465 2400
150 2505 2435
Table 8. Requirement for Concrete cast under different control condition
Class of Control Good Fair Poor

1. Requirements for material
Weight Volume
Cement 1% accuracy 2% accuracy Leveled boxes
Batching
Measuring tank or 1% Flow type meter Estimated visually
Water accuracy 3 % accuracy
Batching
Standard at least 2 fractions
Aggregate Weight 3% accuracy or Volume, gauge
Quality and batching Washed and screed at volume gauge boxes boxes, boxes, wheel
least 3 fractions weight barrows
2. Control of mixes, Under full supervision By an experienced foremen No special
placing, compaction of an inspector with knowledge in good supervision. Amount
experienced in concrete concrete. Adjustment of of mixing water
technology. Continuous mixes when visible changes adjusted visually by
of adjustment of mixes in size and moisture content mix man when
by a field laboratory. of aggregate occur, when consistency of
consistency of concrete concrete changes.
changes.
3. Method of compaction By vibration By hand or vibration By hand
4. Requirement for
average strength at 28
days expressed in % of
nominal strength. 120% 135% 150%
Mix design 115% 125% 140%
Field acceptance
5. Minimum cement*
content for reinforced
concrete Kg/m3.
Unexposed to weather 240 260 280
Exposed to weather 260 280 300
 This standard includes a separate minimum limit on cement in addition on cement in addition to
requirements for strength and durability the mixture must be based on whichever criterion leads to
a larger amount of cement.

Table 8.28Approximate requirements of mixing water (W0) for different

types of structures and maximum sizes of aggregates.
Types of Methods of Max. Slump Water (lit/m3 concrete) for indicated maximum
cements compaction consistency size of angular course aggregate and natural.
15 20 25 30 40 50
Un reinforced or By hand Plastic, 10mm 215 200 195 190 180 170
lightly reinforced Vibrator Stiff, 5mm 195 180 175 170 160 150
foundations or slabs
Reinforced By hand Plastic flowing, 225 210 205 200 190 -
foundations or slabs, 12.5mm
un reinforced or Vibrator Plastic stiff, 205 190 185 180 170 -
slightly reinforced 75mm
walls or columns
Reinforced columns, By hand Flowing, 18mm 235 220 215 210 200 -
beams, walls, hollow Vibrator Plastic, 10mm 225 200 195 190 180 -
block slabs
Note: 1) For rounded aggregate like pebble etc. reduce 10%
2) For reinforced concrete with water reducing admixtures or entrained concrete reduce 5 to 10%
3) For manufactured sand (sharp angular) add 5 to 10 %
4) For type V cement reduce 5%
Approximate amount of entrapped air (Ao) in normal 20 15 10 10 9 -
concrete (liter)
45 40 35 30 30 -
Recommended max. entrained air (Ao) (liter)
Table 10. Maximum size of aggregate recommended for various types of constructions
Type of element Dimensions of sections (cm)

10-15 15-20 20-35 35-75
Un reinforced or slightly Maximum size of aggregate (mm)
reinforced foundations or 25-40 40 40-50 50
slabs
Reinforced foundations or 20-25 25 25-40 40
slabs, un reinforced or
lightly reinforced walls or
columns
Reinforced beams, 15-20 20-25 25-30 30
columns, walls, hollow
block slabs
N.B. Maximum size should not be greater than 1/5 of minimum dimensions of sections or larger than ¾ of
minimum clear spacing between reinforcing bars.

EXPERIMENT No. 16
Test Method for the Determination of Water Absorption of Burnt Clay-Building

Bricks.
1. Scope:
This test method covers the determination of water absorption of burnt clay
building bricks.
2. Theory:
Brick for external use must be capable of preventing rainwater from passing
through them to the inside of walls of reasonable thickness. A good brick should absorb
water maximum 1/7th of the weight of the brick.
3. Apparatus:
3.1 A sensitive balance: capable of weighing with in 0.1 percent of the mass of the
specimen.
3.2 Well-ventilated oven.
4. Preconditioning.
Take 3 bricks and dry in a ventilated oven at a temperature of (110  5) 0c till it
attains substantially constant mass cool the specimen to room temperature and obtain its
weight (M1). Specimen warm to touch shall not be used for the purpose.
5. Procedure:
Immerse completely dried specimen in clean water at a temperature of 27  20C
for 24hr. Remove the specimen and wipe out any traces of water with a damp cloth and
weigh the specimen. Complete the weighing with in 3 mins after the specimen has been
removed from water (M2).

6. Observation and Calculation:
OBSERVATION SHEET
WATER ABSORPTION OF BURNT CLAY BUILDING BRICK
Sample No. Weight of brick Weight of brick Water Average

after oven dried after immersion in Absorption % water
(M1) gm clean water (M2)gm absorption %
1
2
3
Water absorption, percent by mass, after 24-hrs immersion in cold water is given by the
formula
M 2  M1
Water absorption = x 100
M1
7. Result:
Water absorption burnt clay building brick = ______________
8. Question:
A) Describe the characteristics of good bricks?

B) State the maximum limit on water absorption of building bricks?
C) What is the standard size and weight of building brick?

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BDUEF school of civil and water

Test Method for Standard consistency

% Water =(A/500gm) *100

Where: A= Weight of water taken

Construction materials lab. Manual 1

STANDARD CONSISTENCY OF CEMENT

Trial Percentage of Un penetrated Depth From the

Construction materials lab. Manual 2

Time of setting of Hydraulic cement by Vicat Needle

Construction materials lab. Manual 3

INITIAL SETTING TIMES OF CEMENT

Trial Time in min. Un penetrated Depth From the

Construction materials lab. Manual 4

Test Method for the determination of Soundness of cement

Construction materials lab. Manual 5

5. Observation and calculation

Trial No Initial Distance b/n Final distance Soundness Average

Expansion of cement (B-A) _____mm

Construction materials lab. Manual 6

Test Method for Specific Gravity and Absorption of Coarse Aggregate

Construction materials lab. Manual 7

Nominal Maximum size Minimum mass of test of sample (Kg)

Construction materials lab. Manual 8

Bulk sp. gr. = A/(B-C)

Bulk sp. gr. (SSD) = B/(B-C)

Apparent sp. gr. =A/(A-C)

6.2 Absorption – Calculate the percentage of absorption as follows:

Absorption, %= (B-A)/A *100

Construction materials lab. Manual 9

Construction materials lab. Manual 10

6. observation and calculation

6.1. Bulk specific gravity

Bulk sp. Gr. = A

Bulk sp. Gr. (SSD) = 500

Construction materials lab. Manual 11

Test Method for the determination of Moisture Content of Coarse Aggregate.

Construction materials lab. Manual 12

Result: Moisture Content =

Construction materials lab. Manual 13

Nominal maximum size Test sample size minimum

Construction materials lab. Manual 14

6. Observation and Calculation

Table 1.2 Sieve Analysis of Fine Aggregate

Construction materials lab. Manual 15

Construction materials lab. Manual 16

Construction materials lab. Manual 17

Construction materials lab. Manual 18

Test Method for the determination of Silt Content of Fine Aggregate.

Construction materials lab. Manual 19

Construction materials lab. Manual 20

7. Observation and Calculation

BULK DENSITY AND PERCENTAGE OF VOIDS FOR COARSE AGGREGATE

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BULK DENSITY AND PERCENTAGE OF VOIDS FOR FINE AGGREGATE

Table 1. Details of Containers to be used for the bulk density tests

Table 2. Unite weight of water

Construction materials lab. Manual 22

Construction materials lab. Manual 23

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5. Observation and calculation

RAM NO. _ Location

RAM Operator Date _____

RAM No ______ Location