2. Kannur – 670 563
LABORATORY RECORD
Name : Year :
Semester :
Branch :
Roll No : Univ.Reg.No :
Certified that this is the bonafide record of the work done in the Laboratories of the
Government College of Engineering , Kannur.
By
----------------------------------------------------------------------------------
3. Place:
Date: Staff-in-Charge
CONTENTS
Ex No. Date
Name of Experiments
Page No. Grade Initials
1
Grain size distribution of fine &
coarse aggregates
2
Bulk density, Voids ratio, Porosity
& Specific gravity
3
Bulking of sand
4
Aggregate crushing value
5
Aggregate impact value
6
Fineness of cement
7
Normal consistency of cement
8
Initial &final setting time of cement
9
Compressive strength of cement
10
Test on timber beam
11
Test on clay roofing tiles
12
Compressive strength of bricks
13
Rockwell hardness test
14
Brinell hardness test
15
Impact test :Izod & Charpy
4. GRAIN SIZE DISTRIBUTION OF FINE &
COARSE AGGREGATES
Experiment No: 1
Date:
AIM:
To determine the particle size distribution of fine and coarse aggregates.
GENERAL:
The aggregate most of which passes IS: 4.75 mm sieve is classified as fine
aggregate. The fine aggregates obtained from natural disintegration of rocks and
deposited by streams are known as natural sands. Fine aggregates resulting from
crushing of hard stone are known as crushed sand.
The aggregate most of which is retained on IS 4.75 mm sieve is classified as
coarse aggregate. This may be in the form of uncrushed gravel or stone resulting from
natural disintegration of rocks. Crushed gravel or stone is obtained by crushed gravel
or hard stone.
Sieve analysis is carried out for the determination of fine and coarse
aggregates by sieving or screening. Sieves of size 80 mm, 40mm, 20mm, 10 mm, 4.75
mm, 2.36 mm, 1.18 mm, 600 micron, 300 micron &150 micron confirming to IS: 460.
5. APPARATUS:
a) Balance: -The balance shall be such that it is readable and accurate to 0.1% of
the weight of the test sample.
b) Sieves:- sieves of the sizes given in table 1 & 2 confirming to
IS: 460-1962 shall be used.
PROCEDURE:
Take2 kg of air-dry sample of the fine aggregate (3 kg of coarse aggregate) and sieve
successively on the appropriate sieves starting with the largest. Care shall be taken to
ensure that the sieves are clean before use. Each sieve shall be taken separately over a
clear tray until not more than a trace passes, but in any case for a period of not less
than 2 minutes. If a mechanical sieve shaker is used, arrange the set of sieves in the
order of their aperture sizes in such a way that the sieve having smallest opening
comes at the bottom and a minimum of 10 minutes sieving will be required. Weigh
the aggregate retained in each sieve . Draw a graph taking logarithm (Log 10 ) of
aperture size of the sieve on the X-axis and % finer on the Y-axis.
Reporting of results: -
The result shall be calculated and reported as follows
The sieve opening corresponding to 10% passing (D10) gives effective size.
The ratio of sieve opening corresponding to 60% (D60) to sieve opening
corresponding to 10% passing (D10) gives uniformity coefficient.
The sum of the cumulative % retained in each of the sieves divided by 100 gives
the fineness modulus of the aggregate.
Grading zone can be determined by plotting a graph with logarithm of aperture size
of the sieves versus % finer according to value given in table 3.
6. OBSERVATIONS AND CALCULATIONS: -
Coarse Aggregate
Weight of coarse aggregate used for sieving = ……………Kg
IS Sieve
size
Wt.Retained
(g)
%Wt
Retained
Cumulative
%
Wt.Retained
%Wt.
passing
Remarks
80 mm
40 mm
20 mm
10 mm
4.75 mm
2.36 mm
1.18 mm
600 micron
300 micron
150 micron
Residue
Check
Table: 1- sieve analysis of coarse aggregate
Fine aggregate
Weight of fine aggregate used for sieving = ………..…Kg
IS Sieve
size
Wt.Retained
(g)
%Wt
Retained
Cumulative %
Wt.Retained
%Wt.
passing
Remarks
10 mm
4.75 mm
2.36 mm
1.18 mm
600 micron
300 micron
150 micron
Residue
Check
Table: 2- sieve analysis of fine aggregate
7. SPECIFICATION FOR FINE AGGREGATE
(IS: 383-1970)
IS Sieve
Percentage passing
Grading zone I Grading zone II Grading zone III Grading zone IV
10 mm 100 100 100 100
4.75 mm 90-100 90-100 90-100 95-100
2.36 mm 60-95 75-100 85-100 95-100
1.18 mm 30-70 55-90 75-100 90-100
600 micron 15-34 35-59 60-79 80-100
300 micron 05-20 08-30 12-40 15-50
150 micron 00-10 00-10 00-10 00-15
Table: 3-values for grading zones
RESULTS: -
Fine aggregate Coarse aggregate
1.Effective size (D10) mm
2.Uniformity coefficient (D60/D10)
3.Fineness modulus
4.Grading zone
DISCUSSIONS: -
(Discuss about the grading curves obtained. What is the average size of Fine
aggregate and Coarse aggregate in the given sample?)
BULK DENSITY, VOID RATIO, POROSITY
AND SPECIFIC GRAVITY
8. Experiment No. 2
Date:
AIM:
To determine the bulk density, void ratio, porosity and specific gravity of the
given fine and coarse aggregates in loose and compact states.
GENERAL:
In estimating quantities of materials and in mix computations, when batching
is done on a volumetric basis, it is necessary to know the conditions under which the
aggregate volume is measured viz (a) loose or compact (b) dry or damp. For general
information and for comparisons of different aggregates, the standard conditions are
dry and compact. For scheduling volumetric batch quantities the unit weight in the
loose, damp state should be known.
Bulk density (unit weight) is the weight of a unit volume of aggregate, which
is usually expressed in kg. per litre.
Void ratio refers to the spaces between the aggregate particles. Numerically
this void space is the difference between the gross or overall volume of the aggregate
and the space occupies by the aggregate particles alone. Void ratio is calculated as the
ratio between the volume of voids and volume of solids.
Porosity is the ratio between the volume of voids and the total volume.
Specific gravity of aggregate is the ratio of the specific weight of aggregate
and specific weight of water.
APPARATUS:
a) A balance sensitive of 0.5% of the weight of sample to be weighed.
b) A cylindrical container having sufficient capacity.
c) A tamping rod of 16 mm diameter and 60mm long rounded at one end.
d) A measuring jar.
PROCEDURE: -
Take the weight of the cylindrical container (W1). Fill water in the container up to the
brim and find the weight (W2). From these two, calculate the volume of the container
9. (V1). Fill the given sample of aggregate 1/3rd
full in the container and give 25 strokes
with the rounded end of the tamping rod. Fill the container to overflowing by filling in
the same manner as above in two steps. Remove the surplus aggregate using the
tamping rod as a straight edge. Take the weight of the container with the aggregate
(W3). Add measured quantity of water to the aggregate in the container slowly until
the voids are completely filled with water. Note the volume of water added (V2), (To
verify the value of V2, take the weight of the container with aggregate and water and
find the weight of water added).
For loose aggregate.
Fill the container to overflowing by means of a shovel, the aggregate being
discharged from a height not exceeding 50mm above the top of the container. Level
the surface of the aggregate with a straight edge. Obtain the weight of the aggregate.
Repeat the same procedure used for compacted aggregate to ascertain the other
quantities.
OBSERVATIONS AND CALCULATIONS: -
Sl.
No.
Particulars
Fine aggregate Coarse aggregate
Loose Compact Loose Compact
10. 1 Weight of Container (W1) kg
2
Weight of Container +Water
(W2) kg
3
Weight of Container +
Aggregate (W3) kg
4 Volume of container (V1) lit
5
Volume of Water added
=Volume of voids (V2) lit
6
Weight of Aggregate
(W3-W1)
7 Volume of Solids (V1-V2))
8
Bulk density =
Wt. of Aggregate
Total volume of aggregate
9
Void ratio = Volume of voids
Volume of solids
10
Porosity = Volume of voids
Total volume of aggregate
11
Sp. Wt. of aggregate =
Wt. of Aggregate
Volume of aggregate
12
Specific gravity =
Sp. Wt. of aggregate
Sp. Wt. of water
RESULTS:
Sl
NO
Parameters
Fine aggregate Coarse aggregate Remarks
Loose Compact Loose Compact
1 Bulk density (kg/litre)
2 Void ratio
3 Porosity
4 Specific gravity
11. DISCUSSION:
(Compare the values with the usual value of the aggregates recommended for normal
concreting work)
BULKING OF SAND
Experiment No: 3
Date:
AIM:
To determine the bulking characteristics of given sand.
GENERAL: -
The free moisture content of fine aggregate results in bulking of volume. Free
moisture forms a film around each particle. This film of moisture exerts surface
12. tension, which keeps the neighboring particles away from it. Hense no point of
contact is possible between the particles. This causes bulking of the volume .The
extent of bulking will depend upon the percentage of moisture content and particle
size of the fine aggregate. Bulking increases with the increase in moisture content up
to a certain limit and beyond that, further increase in moisture content results in the
decrease in volume.
Sand brought to work site may contain an amount of moisture, which will
cause bulking. When it is loosely filled into a measuring container, it occupies larger
volume than it would occupy if dry. Hence if sand intend to use in a concrete mix is a
measure by loose volume, it will be necessary to increase the volume of sand by
‘percentage bulking’. Otherwise the yield of concrete will be reduced and the mix
becomes deficient in sand and the aggregate is prone to segregation resulting in
honey-combing of concrete.
APPARATUS: -
Measuring jar, balance, scale and porcelain bowl.
PROCEDURE: -
Take about 200ml. of dry sand from the sample and find its weight. Add water at
2% by weight of dry sand and mix it thoroughly by hand. Pour the damp sand into the
measuring jar and consolidate it by shaking. Level the top surface using the scale.
Note its volume (V). Repeat the test with different % of water. Finally pour water into
the measuring jar containing the moist sand until the water just submerge the sand
completely. Note the volume of sand (V0). Calculate the % bulking using the formula.
Percentage bulking = V- V0 × 100
V0
Draw the Percentage bulking versus moisture content curve and find the maximum
Percentage bulking and corresponding moisture content.
RESULT:-
1. Maximum percentage of bulking =
2. Moisture content at maximum bulking =
DISCUSSION: -
14. 8 25
9 30
AGGREGATE CRUSHING VALUE
Experiment No: 4
Date:
AIM:-
To determine the aggregate crushing value of the given coarse aggregate.
GENERAL: -
The aggregate crushing value gives a relative measure of the resistance of an
aggregate to crushing under a gradually applied compressive load. Crushing value is
defined as the ratio of fines passing a standard sieve produced by crushing under
standard condition to the weight of coarse aggregate expressed as a percentage.
15. Aggregate crushing values as determined by the IS code method shall not
exceed 30 for aggregate to be used for making concrete for wearing surface such as
roads and runways and 45 for uses other than wearing surface.
APPARATUS: -
An open-ended 150mm cylindrical cell with appropriate base plate and metal
tamping rod 16mm diameter 45cm long rounded at one end. A balance of capacity
5kg, IS sieves 12.5mm, 10mm and 2.36mm, compression testing machine capable of
applying a load of 40T and which can be operated to give a uniform rate of loading so
that a maximum load of 40T is reached in 10 minutes.
PROCEDURE: -
Take required quantity of aggregate passing on a 12.5mm sieve and retained
on a 10mm sieve. When aggregate of the required size is not available, test may be
conducted on the available sample, the specifications for cylinder and sieve separating
the fines may be taken from IS: 2386-1963. The aggregate should be in a saturated
surface dry condition. Fill the test sample of aggregates in the cylinder in thirds, each
part being subjected to 25 strokes from the tamping rod. Take the weight of the test
sample (A) after leveling the surface of the aggregate and insert the plunger sot that at
rests horizontally on the surface of the aggregates. Place the apparatus with the test
sample and the plunger between the platens of the testing machine and apply the load
fairly at uniform rate so that the total load of 40T reaches in 10 minutes.
Release the load and remove the material from the cylinder and sieve it
through 2.36mm sieve. Collect and weigh the fraction passing the sieve (B).
Aggregate crushing value can be calculated as (B/A) x 100.
OBSERVATIONS AND CALCULATIONS:-
Weight of dry sample passing through IS 12.5mm sieve and retained on
IS: 10mm sieve (A) =
Weight of aggregate passing through the IS 2.36mm
Sieve after the test (B) =
Aggregate crushing value =
16. RESULT: -
Aggregate crushing value for standard size aggregate =
DISCUSSION: -
(Discussion the suitability of aggregate for construction)
AGGREGATE IMPACT VALUE
Experiment No: 5
Date:
AIM: -
To determine the impact value of the given aggregates.
GENERAL:-
The property of a material to resist impact is known as toughness. Due to
movement of vehicles on the road aggregates are subjected to impact resulting in their
breaking down into smaller pieces. The aggregates should therefore have sufficient
toughness to resist their disintegration due to impact. This characteristic is measured
by impact value test. The aggregate impact value is a measure of resistance to sudden
17. impact or shock, which may differ from its resistance to gradually applied
compressive load.
APPARATUS: -
The apparatus of the aggregate impact value test as per IS: 2386 (Part IV)
1963 consists of:
(i) A testing machine weighing 45 to 60 kg and having a metal base with a
plane lower surface of not less than 30cm in diameter. It is supported
on level and plane concrete floor of minimum 450mm thickness. The
machine should also have provisions for fixing its base.
(ii) A cylindrical steel cup of internal diameter 102mm, depth 50mm and
minimum thickness 6.3mm.
(iii) A metal hammer weighing 13.5 to 14 kg the lower end is cylindrical in
shape, is 50mm long, 100mm in diameter with a 2mm chamfer at the
lower edge and case hardened. The hammer should slide freely
between vertical guides and be concentric with the cup. The free fall of
the hammer should be within 380+ 5mm
(iv) A cylindrical metal measure having internal diameter of 75mm and
depth 50mm for measuring aggregates.
(v) Tamping rod 10mm in diameter and 230mm long rounded at one end.
(vi) A balance of capacity not less than 500g readable and accurate up to
0.1g.
PROCEDURE:-
Take 300g dried aggregate which passes through 12.5mm IS: sieve and
retained in 10mm IS: sieve. Pour the aggregate to fill about 1/3 depth of measuring
cylinder and give 25 blows using the rounded end of the tamping rod. Add two more
layers in similar manner to fill the mould completely. Strike of the surplus aggregates
and takes the weight of aggregates to nearest grams (W1). Fix the cup firmly in
position on the base of machine and place whole of the test sample in it and compact
by giving 25 gentle strokes with tamping rod. Raise the hammer until its lower face is
380mm above the surface of the aggregate sample in the cup and allow it to fall freely
on the aggregate sample. Give 15 such blows at an interval of not less than 1 second
between successive falls. Remove the crushed aggregates from the cup and sieve it
through 2.36 mm IS: sieve until no further significant amount passes in one minute.
Weigh the fraction passing the sieve to an accuracy of 1g (W2). Also weigh the
18. fraction retained in the sieve. Aggregate impact value can be calculated as aggregate
impact value = (W2/W1) x 100 and should be expressed as a nearest whole number.
The following precautions should be taken while conducting the test.
(i) The plunger should be placed centrally so that it falls directly on the
aggregate sample and does not touch the walls of the cylinder in the
order to ensure that the entire load is transmitted on to the aggregates.
(ii) In the operation of sieving the aggregates through 2.36mm IS sieve,
the sum of the weights of the fraction retained and passing the sieve
should not differ from the original weight of the specimen by more
than 1g.
(iii) The tamping is to be done properly by gently dropping the tamping rod
and not by hammering action. Also the tamping should be uniform
over the surface of the aggregate taking care that the tamping rod does
not frequently strike against the walls of the mould.
OBSERVATIONS AND CALCULATIONS:-
Total weight of dry sample (W1) =
Weight of portion passing IS 2.36mm sieve (W2) =
Aggregate impact value = (W2/W1) X100
RESULT: -
Aggregate impact value =
DISCUSSION: -
(Discuss the suitability of the aggregate for road construction)
19. FINENESS OF CEMENT
Experiment No:-6
Date:
AIM :
To determine the Fineness of cement by dry sieving
GENERAL:
Fines of cement has significant role on the rate of hydration and on the rate of
evolution of heat. Cement which is more finely ground hardened more rapidly and has
a higher rate of heat evolution at early ages. Greater finesses improves the
cohesiveness of concrete mix and quality of water rising to the surface of concrete
known as bleeding, is reduced.
Shrinkage cracking is related to the rate of development of strength of concrete. In
general, cement which gains more strength rapidly are more subjected to cracking.
Increasing the fineness of any particular cement, raises its rate of development of
strength and so indirectly increases the risk of shrinkage crack formation.
APPARATUS :
20. IS 90 micron sieve, weighing balance with a sensitivity of 0.1 gm.
PROCEDURE :
Weigh 100gm. of given sample of cement. Place it on a standard IS 90 micron
sieve. Breaking down any air set lumps in the cement sample with finger.
Continuously sieve the sample with a gently wrist motion for a period of, rotating the
sieve continuously throughout the sieving. Weigh the residue after 15 minutes of
sieving. Repeat the procedure for two more such samples.
OBSERVATION AND CALCULATIONS:
Weight of cement taken =
Weight of residue after 15 minutes of sieving =
RESULTS :
Fineness of cement of dry sieving =
DISCUSSION :
(Discuss the quality of the given sample of cement by comparing with IS
specifications.)
22. NORMAL CONSISTENCY OF CEMENT
Experiment No:7
Date:
AIM:-
To determine the normal consistency of the given sample of cement.
GENERAL:-
Since different batches of cement differ in fineness, pastes with the same
water content may differ in consistency when first mixed. For this reason the
consistency of the paste is standardized by varying the water content until the paste
has a given resistance to penetration when it is first mixed.
Consistency is a state of flow and varies with the amount of water added to the
given quantity of cement. More water increases the plasticity of the mortar to flow
whereas reducing its quantity in the paste makes it hard and stiff. The normal
consistency of a cement paste is defined as that consistency which will permit the
Vicat plunger to penetrate to a point 5 to 7 mm from the bottom of Vicat mould when
23. the cement paste is tested. The value of the amount of water required to prepare a
paste of normal consistency is necessary for conducting other tests such as tensile test,
soundness test, setting time test and compressive strength test.
APPARATUS:-
Vicat’s apparatus with Vicat’s plunger, weighing balance, stop watch,
measuring jar, glass plates and porcelain bowl.
PROCEDURE:-
Take 400g of cement and break air set lumps of cement if any by hand. Add
water about 20 percentage by weight of cement. Start a stopwatch when water is
added to the dry cement. Prepare the cement paste such that the gauging time is not
less than 3 minutes nor greater than 5 minutes. The gauging time is counted from the
time of adding water to the dry cement until commencing to fill the mould. Fill the
mould completely and during filling shake the mould slightly to expel air. After filling
level the surface of the mould. Place the mould with the test block with non-porous
plate under the plunger. Lower the plunger gently to touch the surface of the test
block and release it quickly. Note the reading on the scale. Prepare the trial pastes
with varying percentages of water until the amount of water necessary for making up
the normal consistency as defined is found.
RESULT:
Normal consistency of cement =
DISCUSSION:
25. INITIAL AND FINAL SETTING TIME OF CEMENT
Experiment No.8
Date:
AIM:
To determine the initial and final setting time of cement.
GAENERAL:
It is essential that cement set neither too rapidly nor too slowly. In the first
case there might be insufficient time to transport and place the concrete before it
becomes too rigid. In the second case too long a setting time tends to slow up the
work unduly and it might postpone the actual use of structure because of inadequate
strength at the desired age. As per IS: 4081-1968 the setting time of cements when
tested by Vicat apparatus are as follows.
Particulars
Ordinary Portland
cement
Rapid hardening
cement
Low heat
cement
1. Initial setting time
in minutes (not
30 30 60
26. less than)
2. Final setting time
in minutes (not
greater than ) 600 600 600
APPARATUS: Vicat’s apparatus with needles, weighing balance, stopwatch,
measuring jar, porcelain bowl.
PROCEDURE:
Take 400gm. of cement and prepare a neat cement past with 0.85 times of
water required for normal consistency. The preparation of test block for the test is
same as that for the normal consistency test. Start a stopwatch when water is added to
the dry cement. Place the test block confined in the mould and resting on the non-
porous plate below the needle of the Vicat apparatus. Lower the needle gently to
touch the surface of the test block and release quickly. In the beginning the needle
completely pierces the test block. Repeat this procedure until the needle pierces the
block by 5 ± 0.5mm measured from the bottom of the mould. The period elapsing
between the time when water is added to the cement and the time at which the needle
fails to pierce the test block by 5 ± 0.5mm is the initial setting time.
For determining the final setting time, replace the needle of Vicat apparatus by
the needle with an annular attachment. The cement is considered finally set when
upon applying the final setting needle gently to the surface of the test block, the
needle makes an impression thereon, while the attachment fails to do so. The period
elapsing between the time when water id added to the cement and the time at which
the needle make an impression on the surface of the test block while the attachment
fails to do so shall be the final setting time. In the event of a scum forming on the
surface of the test block, use underside of the test block for the determination of final
setting time.
RESULT:
Initial setting time of the given sample =
Final setting time of the given sample =
DISCUSSION:
27. (Discuss the quality of the given sample of cement comparing with IS
specifications)
OBSERVATIONS:
INITIAL SETTING TIME OF CEMENT
Type of cement =
Weight of cement =
Quality of water added =
Sl. No Time Reading(mm) Remarks
28. COMPRESSIVE STRENGTH OF CEMENT
EXPERIMENT. NO.9
Date :
AIM :
To determine the compressive strength of given sample of cement.
GENERAL :
The mechanical strength of hardened cement is the property of material that is
needed in the structural designs. The strength of cement is usually determined from
tests on mortar made with cement. The compressive strength of cement is determined
as represented by compressive strength tests on mortar cubes prepared by standard
method.
APPARATUS :
Moulds for the cube specimens of 50 cm2
face area, vibrating machine,
compression testing machine, apparatus for gauging and mixing mortar etc.
PROCEDURE :
The test specimen shall be in the form of cubes having of face area equal to 50
cm2
made of cement mortar 1:3 .In assembling the mould ready for use, cover the joint
29. between the halves of the mould and between the contact surface of the bottom of the
mould and base plate with a thin film of petroleum jelly, in order to ensure that no
water escapes during vibration. Coat the interior faces of the mould with thin coat of
mineral oil. Place the assembled mould on the table of the vibration machine and
firmly hold it in position by means of suitable clamp.
The material for each cube shall be cement W1 =200 gm
P +3
Standard sand W2 =3W1= 600 gm, water = 4 (W1+W2) g, where p is the
100
Percentage of water for standard consistency.
Place the mixture of cement and standard sand in a non-porous plate. Mix dry
with a trowel for one minute and add the required quantity of water and mix until the
mixture is of uniform colour. The mixing time should not exceed 4 minutes and
should not be less than 3 minutes.
Immediately after mixing the mortar fill it in the cube mould and rod 20 times
with a rod in three layers. Place the remaining quantity of mortar in the hopper of the
cube moulds and pressed it again and then compact the mortar by vibration. The
period of vibration shall be 2 minutes at the specified rate of 12000+ 400 vibrations
per minutes. At the end of the vibration remove the mould together with the base plate
from the machine and finish the top surface of the cube in the mould by smoothing the
surface with the blade of the trowel.
Keep the filled mould at a temperature of 27 + 20
C in an atmosphere of at least
90% relative humidity for 24 hrs. At the end of the period remove them from the
moulds and immediately submerge in fresh water and keep there until taken out just
prior to testing.
TESTING OF MORTAR CUBES
Test 3 cubes for compressive strength at the period mentioned in the IS
specification. The cubes are tested on their sides without any packing. The load shall
be readily and uniformly applied at the rate of 350kg / cm2
/ min.
OBSERVATION AND CALCULATIONS
Weight of cement for one cube = 200g
Weight of sand = 600g
Weight of water for one cube =
Area of the cube face =
30. RESULT:
The average value of compressive strength of cement sand mortar cubes at
(i) 3days =
(ii) 7days =
DISCUSSION:
(Discuss (i) standard sand (ii) the quality of the given sample of cement)
OBSERVATIONS:-
Sample
no
At 3 days age At 7 days age
Load
Compressive
Strength
Average
Compressive
Strength
Load
Compressive
Strength
Average
Compressive
Strength
(N) (N/mm2
) (N/mm2
) (N) (N/mm2
) (N/mm2
)
1
2
3
31. TEST ON TIMBER BEAM
Experiment No:-10
Date:
AIM :
To determine the following properties of the timber specimen by conducting static
bending test.
1) Fibre stress at limit of proportionality
2) Modulus of rupture.
3) Modulus of elasticity
4) Elastic resilience.
GENERAL :
Standard size of specimen is 5 x 5 x 75 cm with 70 cm span. Where a standard
specimen cannot be obtain the dimensions of the test specimen shall be such as to
make the span l = 14 times the depth. Central deflections shall be measured at load
intervals of 50 kg.
EQUIPMENT :
30T U. T. M,Scale.
PROCEDURE :
32. Measure the size of the specimen and fix the span. Assuming the
maximum fibre stress ‘f ‘ (say 1000 kg / cm2
) calculate the maximum central (W) the
specimen can carry.
M = wl = f Z, hence W = 4 f Z
4 l
where M is Maximum B.M
Z is the section modulus = bd2
where ‘b ‘and ‘d ‘ are the breadth and
6
depth of the specimen.
Select a suitable loading range and adjust the machine for that range. Mount
the beam supports over the cross head at correct span and place the specimen, fix the
special loading device to the cylinder device at top. Start the motor and slowly open
the inlet valve until the ram is floated. Adjust the pointer to the zero reading, raise the
cross head the central loading device just touches the top of the beam specimen
.Adjust the deflection dial to zero reading. Now slowly load the specimen opening the
inlet value and note deflections corresponding to the load increments until the
specimen fails. Also note the maximum load .Now draw load deflection curve.
Determine the slope of the straight line portion of the graph (P1)
∆
RESULT :
1. Fibre stress at limit of proportionality =
2. Modulus of rupture =
3. Modulus of elasticity , =
4. Elastic resilience, =
DISCUSSION :
(Discuss the quality of the given timber.)
33. OBSERVATIOS :
Load, kg
Central
deflection,mm
1. Span of the test specimen l (mm) =
2. Breadth of the test specimen b (mm) =
3. Depth of the test specimen d (mm) =
4. section modulus = bd2
(mm3
) =
6
5. Moment of inertia I = bd3
(mm4
) =
12
6. Load at limit of proportionality P (N) =
7.Maximum load P1
(N) =
8. Fibre stress at limit of proportionality = Pl (N/mm2
) =
4Z
34. 9. Equivalent Fibre stress at Maximum
load = = P1
l (N/mm2
) =
4Z
10. Modulus of elasticity , =P1
l3
/48I∆ (N/mm2
) =
11. Elastic resilience = work to limit of proportionalty/volume
(Nmm / mm3
) =
35. TEST ON CLAY ROOFING TILES
Experiment No:-11
Date:
AIM :
To determine the following properties of clay roofing tiles
(i) water absorption percentage (ii) permeability (iii) breaking load.
GENERAL :
The roofing tiles shall be made from suitable clay of even texture and shall be
well burnt .They shall be free from irregularities such as twists,bends,cracks and
laminations. The roofing tiles shall be free from impurities such as particles of stone,
lime or other foreign materials visible to naked eye or on the fractured face of tile.
When struck the tile shall give a ringing sound and when broken the fracture shall be
clean and sharp at the edges. The average weight of six tiles shall not be less than 2Kg
and not more than3Kg. The strength requirements of roofing tiles as per IS654-1992
are (1) water absorption (2) permeability (3) breaking load.
APPARATUS :
Tile flexure strength testing machine. weighing balance,eletric oven.
PROCEDURE :
(1) water absorption Test:
36. Dry six tiles by placing in the oven at 1050
C to 1100
C till they attain
constant weight and them cool and weigh (A) Immerse the dry specimen in
clean water at 240
C to 300
C for 24 hrs .Take out the specimens wipe off the
surface water and weigh the specimens (B)
The % water absorption = (B-A ) x100
A
The average % water absorption of six tiles can be taken as the % water
absorption
(2) Permeability test :
This test can be conducted at 27+/-20
C and relative humidity of 65+/-5%.The
tile shall be fitted at the bottom of the trough and the space between the sides of the
trough plugged water tight with a suitable materials like wax or bitumen.
Pour water into the mould so that it stands over the lowest tile surface
to a height of 5cm and keep it for a period of six hours. After the period
the bottom of the tile shall be carefully examined to see whether the water
has seeped through the tiles.
(3) Breaking load.
Test six tiles after soaking them in water at 27+/-20
C for 24hrs
in the wet condition. Support the tile evenly flat wise as the bearer set
with a span of 25cm and resting on the bottom surface. Apply the load
with the direction of the load perpendicular to the span at a uniform
rate of 450 to 550 N/min.Take the individual bearing load of each of
the six tiles separately in the wet condition and calculate the average
value .
PRINCIPLES OF TILE TESTING MACHINE :
Loding roller Upper lever
R
D E F
G C
Lower lever
37. W
DE = 15 cm EF =7.5 cm AC = 7.5 cm BC =22.5 cm
Lower arm
R
G A C B
7.5 cm 22.5 cm W
Taking moments at A
W(7.5+22.5)– (P x 7.5) =
W = 7.5 P
30
P = 30W ……(1)
7.5
Upper lever R
D C F
P
15 cm 7.5 cm
Taking moments at F
R x 7.5 - P (15 + 7.5 ) = 0
7.5 R = 22.5 x 30W
38. 7.5
R = 22.5 x 30 = 12 W
7.5 x 7.5
ie R = 12W
RESULTS :
DISCUSSION :
(Discuss specifications of M P roofing tiles as per IS 654-1962 like sample size,
criteria for conformity etc.)
Sl
no
Identificat
-ion mark
Length
(cm)
Width
(cm)
Dry
wt.
(Kg)
%Water
absorption
Breaking
load(KN)
Permeabi-
lity
Classificatio
n as per IS:
654-1992
39. OBSERVATIONS AND CALCULATIONS :
Water absorption test :
Sl
n
o
Identification
mark
Length
(cm)
Width
(cm)
Dry
wt.
(Kg)
Wet
wt.
(Kg)
%Water
absorption
Average
%Water
absorption
Classification
as per IS:
654-1992
Breaking load test :
Sl
no
Identification
mark
Length
(cm)
Width
(cm)
Dry
wt.
(Kg)
Breaking
load
(KN)
Average
breaking
load (KN)
Classification
as per
IS 654-1992
40. COMPRESSIVE STRENGTH OF BRICKS
EXPERIMENT NO.12
Date :
AIM
To determine the compressive strength of the given sample of brick.
GENERAL :
Bricks are generally subjected to compression and rarely to tension. The usual
crushing strength of common hand moulded well burnt bricks is about 5 to 10 N/mm2
varying according to the nature of preparation of the clay.
APPARATUS:
A compression testing machine.
PROCEDURE :
Take 5 bricks, remove unevenness observed in the bed face to provide two
smooth parallel faces by grinding. Immerse the bricks in water at room temperature
for 24 hours. Take out the specimen from water and drain out any surplus moisture at
room temperature. Fill the frog (if provided) and all voids in the bed face flush with
cement mortar. Remove and wipe out any traces of moisture.
Place the specimen with flat faces horizontal and mortar filled face facing
upwards between two 3-plywood sheet each of 3 mm thickness and carefully cantered
between plates of the testing machine. Apply an axial load at a uniform rate 14 N/mm2
Per minute till failure and note the maximum load at failure.
RESULT:
Average compressive strength of brick =
DISCUSSION :
41. (Discussion the quality of the given sample of bricks).
OBSERVATIONS & CALCULATIONS
Brick No Dimensions of
the brick
(LxBxD ) mm
Average area
of the bed face
mm2
Maximum
load at
failure(N)
Compressive
strength
(N/mm2
)
1
2
3
4
5
Maximum Load of failure
Compressive strength = _________________________
Average area of the bed face
43. ROCKWELL HARDNESS TEST
EXPERIMENT NO:13
Date :
AIM :
To study the Lucknik hardness testing machine and to find the Rockwell
hardness number of the materials of the given specimens.
GENERAL:
The test consists in forcing an indenter of standard type (cone or ball) into the
surface of the test piece in two operations and measuring the permanent increase of
the depth of indentation “e” of this indenter under specified conditions. The unit of
measurement of “e” is 0.002 mm from which a number known as the Rockwell
hardness is deduced.
The load and the indenter to be used for a particular test is decided from an
approximate relative hardness of the different materials. In general for hard materials
diamond cone indenter is used and for soft materials steel ball indenter is used.
Sl
no
Material Indenter Total load Scale symbol Scale
1 Very hard and thin Diamond cone 60 A Black
2 Very hard Diamond cone 150 C Black
3 Soft Steel ball
1.5875mm.dia.
100 B Red
4 Soft and thin Steel ball
1.5875mm.dia
60 F Red
Usually C and B are used. HRC;used for very hard materials.
F0 = ,Preliminary load = 10 kgf
44. F1 =Additional load 140 Kgf.
F1 = F0 + F1 =150 kgf
e = Permanent increase of depth of indentation under the preliminary load after
removal of additional load. This is expressed in units of 0.002 mm
HRC =Rockwell hardness C =100-e
Range of the scale is 0 to 100 and block scale is to be used.
HRB used for soft materials. The ball inter has to be used.
F = F0 + F1 = 10 +90 = 100 kgf
HRB =Rockwell hardness B =130-e
Range of the scale is 30 to 130
0.2mm
F0
F0+F1
F0
SURFACE
DATUM
20
80
e a
e p
HRC =100-e
ep =Depth of indentation due to F0
ea =Increase in depth of indentation due to F1
45. Test requirements:-
1.The surface of the test piece shall be smooth and even and free from oxide
Scales and foreign matter.
2. The thickness of the test piece shall be at least 8 times the permanent
increase of depth “e”
3. The distance between centres of two adjacent impressions shall be at least 4
times the diameter of indentation and the distance from the center of the
indentation to the side of the test piece shall be at least 2.5 times the
diameter of indentation.
4.The dial of the indicator shall be set at initial position and the load increased
without sudden shock within 2 to 8 seconds.,
EQUIPMENT:
Lucknik hardness testing machine
PROCEDURE
Put the required weight on the pan. Insert the indenter and fasten with a screw.
Place the specimen on the object table and turn the wheel to raise the elevation screw
until specimen touches the indenter. Turn the wheel slowly to make the indenter
penetrate the specimen until the small pointer of the dial indicator is on the red dash.
Now the specimen is subjected to the preliminary load of 10kgf.Bring the big pointer
to read zero for C scale (black) or 30 of B-scale (red). Press the releasing device to
increase the load from F0 to F1 inducing a further driving of indenter into the
specimen.
Keep the load stationary for 4 to 6 seconds for hard materials and 6 to 8
seconds for soft materials. Release the load by turning the crank in the reverse
direction. The reading corresponds to the position of the big pointer gives the
hardness number directly (black scale HRC and red scale HRB).
47. BRINELL HARDNESS TEST
EXPERIMENT NO: 14
Date :
AIM :
To study the Brinell hardness testing machine and to find the Brinell hardness
number of the material of the specimen supplied.
GENERAL: -
The test consisting in forcing a steel ball of diamater “D” under a load “F” into
the test piece and measuring the diameter of the indentation left in the surface “d”.
The Brinell hardness is obtained by dividing the test load F in kgf.by the curved
surface area of indentation in square mm.
Total load
HBS or HBW =
Surface area of indentation
F
=
╥
Dh where “h” is the depth of indentation in mm.
F
=
╥D [D─√ D2
─d2
]
2
2 F
=
╥D [D─√D2
─d2
]
HBS =Brinell hardness in case where a steel ball is used for materials whose HB is
not exceeding 450.
HBW = Brinell hardness in case where as hard metal ball is used for materials whose
HB is not exceeding 650
48. Example :- 160 HBS 10/3000/15 = Brinell hardness of 160 determined with a steel
ball of 10 mm diameter and with a test force of 3000 kgs. Applied for 15 seconds.
Test requirement:-
1. The surface of the test piece shall be sufficiently smooth and even.
2. The thickness of test piece shall not be less than 8times the depth
of indentation h .
3. The distance of centre of indentation from the edge of test piece shall be at
least 2.5 times the diameter of the indentation and the distance between center
of two adjacent indentation shall be at least 4 times the diameter of
indentation.
4. The test load is attained without shock or vibration. The test load shall be
Maintained for 10 or 15 seconds.
5. It is desirable that the diameter “d” of the indentation should range between
0.25D and 0.05 D
The ratio of F/ D2
shall be chosen according to the material.
Material F/D2
Mild steel 30
Brass 10 or 15
Copper 10
EQUIPMENTS:
Brinell hardness testing machine, traveling microscope.
49. PROCEDURE :
Considering the material of the specimen and the size of the ball indenter
select a suitable load and suspend weights on the yoke tray accordingly. Insert the
steel ball indenter in position and place the specimen on the work table. Raise the
specimen by turning the hand wheel until the contact with the steel ball is obtained.
Close the valve and smoothly pump oil without causing any shock using the hand
lever until the desire load is obtained. Maintaine the load for specified time (10 to 15
seconds)for steel and 30 ±2 seconds for light metals. Then slowly open the valve there
by raleasing the oil pressure and the load. Lower the specimen by turning the hand
wheel.
Remove the specimen and measure the diameter of indentation in two perpendicular
directions (d1and d2 ).The average of d1and d2 is the diameter of indentation
“d”.Calculate HBS using the formula.
RESULT :-
Brinell Hardness no of ( ì )
( ì ì)
51. IMPACT TESTS: IZOD, CHARPY
Experiment No:-15
Date:
AIM :
a) To draw calibration curves for the machine used.
b) To find the impact values (izod and charpy) of the materials of the
standard specimens.
EXPERIMENT:
Avery impact testing machine, setting gauges.
GENERAL:
For deciding the suitability of material, which is expected to resist repeated
shocks, the ordinary static tensile test is not formed satisfactory. Testing machines
have been decided so that a specimen can be subjected to shock load. The energy
required to break the specimen is taken as a measure of the resistance of the
material against shock loading. The property of a material relating to the work
required to cause rupture has been termed as “toughness”.
AVERY IMPACT TESTING MACHINE:
The machine consists of a pendulum with a hammer having a striker at the
end. The length of the pendulum is 0.825m with a hammer weight of 22.05kg for
izod and 20.996kg for charpy along with its accessories. The machine has two
capacity ranges 0 to 164 J for izod test (cantilever test) and 0 to 300 J for charpy
test(beam test). Two control levers are fitted one for releasing the pendulum and
other for clamping the specimen. The angle of raise of pendulum after impact is
read from the dial. A stop is fitted to support the pendulum in the rest portion.
Two ratchets fitted to the pendulum lock at the 164 J or 300 J height
which ever is selected.
52. PROCEDURE:
a) Calibration curves:-
Initial energy E1 = Wh1
= W( L- LcosΦ1) –––––––– (1)
Final energy E2 = Wh2
= W( L- LcosΦ) –––––––– (2)
Loss of energy or impact value = EL = E1 - E2 = WL ( cosΦ- cosΦ1)
L = 0.825m
W=22.057 Kg for Izod and 20.996 Kg for charpy
Φ1 = 85.35° for Izod
Φ1= 140° for Chatpy
E1 = 164J for izod test and 300J for charpy test. Substitute the
corresponding values in eqn: (1) and find Φ1. To find a relation between
ELand Φ1. Substitute for W.Land Φ1.for varying values of Φ1,calculate the
corresponding values of EL and draw a curve of EL Vs Φ which is the
calibration curve. Now during a test if the pointer indicates an angle of Φ2
after impact ,the corresponding impact value can be read from the
calibration curve.
Φ1
Φ
L L
L
h1
h2
53. W W
W
B (1) Cantilever test (izod and charpy)
Fit the striker with the horizontal face in the striker
position. the appropriate grips are positioned .after inserting the test piece with the
notch to the right, set the specimen for the correct height with the setting gauge and
lock the grips with the right hand lever, with the safety lever in the izod position ,raise
the pendulum to 164J position. Rotate the maximum pointer anticlockwise until it
contacts the fixed pointer attached to the pendulum. Release the pendulum by the left
hand lever.After the pendulum has passed the test piece it will carry the maximum
pointer and leave it indicating the angle of raise of pendulum after impact. Arrest the
pendulum by catching the handle with the right hand. after pulling the pendulum back
raise the stop to allow the top of the pendulum to rest on it. Repeat the test by using
the remaining two notches of the specimen. Take the average of these three values as
the impact value of the specimen.
2) Beam test (charpy test):
In this case fit with the striker with the central vertical
edge in the striking position. Position and lock the anvil. Place the test piece across
the anvil with the notch to the left locating it centrally with the centering gauge with
the safety lever in the charpy position raise the pendulum to the 300J position and
release. Read the values indicated in the dial.
RESULT :
a) calibration curves were drawn.
b) Impact value of the materials of standard specimen (mild steel)
1. By izod test =
2. By charpy test =
DISCUSSION:
54. OBSERVTION:
Calibration curve Test Result
Φ EL(kgm) EL(kgm) Angle Φ2 EL (J)
Mean
EL (J)
0 Izod
10
20
30
40
50
60
70 Charpy
80
90
100
110
120
130
140
