MT LabMANUAL

8/4/2019 MT LabMANUAL

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AXIAL COMPRESSION TEST ON BRICK

Exp. No:

Date :

AIM

To find the ultimate compressive strength of Brick

EQUIPMENT

Universal testing machine, vernier calipers, scale.

THEORY

The compressive strength of masonry Units (bricks) is used as an index along with

the type of motor to find the basic compressive strength of brick masonry. The bricks are

tested on their flat faces, after filling the indentation on the surface known as Frog by rich

1:1 cements mortar. The bricks are kept under water and tested under wet condition.

PROCEDURE

(a) Preparation

1. Using the 1:1 Cement Mortar, fill in the frog and level the flat surface of the brick.2. When setting is complete keep the brick under water.

(b) Test

1. Take the sample out of water. Wipe the water from its surface.2. Measure the dimension of the brick.3. Determine the weight of the brick samples.4. Place the sample under platens of the Universal Testing Machine, in between two

plywood sheets and apply compressive load at prescribed rate.

5. Note the ultimate load.


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FORMULA

(i) Ultimate compressive strength of brick unit = Ultimate Comp. Load ( N)

Area of flat surface (mm2)

OBSERVATION

Bricks

Edges: (Whether skewed / truly rectangular / Sharp)

Visible defects: (if any)

TABULATION

Sl.No Dimension of BrickAverage area

of bed faceMax load at

failureCompressive

StrengthUnit Length Breath Depth

mm mm mm mm2

kN N/mm2

1

2

3

Average

CALCULATION

Ultimate compressive strength of brick unit = Ultimate Comp. Load

Area of flat surface


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i) Fcb1 =

ii) Fcb2 =

iii) Fcb3 =

RESULT

The average ultimate compressive strength of

Brick samples = ..


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AXIAL COMPRESSION TEST ON CUBE AND CYLINDRICALMOULD

Exp. No:

Date :

AIM

To determine the compressive strength of concrete by testing cube and cylinder

specimen.

EQUIPMENT

Universal testing machine, vernier calipers, scale, cube moulds and cylindrical

moulds, tamping rod, trowels, Non-absorbent platform, hand scoop and compression testing

machine

THEORY

The compressive strength of concrete is determined by testing 150 mm size concrete

cubes under compression, 28 days after curing. The rate of loading is kept at 14/mm2/min.

the failure of the specimen is called as hour glass type of failure. This happens because of

lateral restraint provided by the plates to the cubes.

PROCEDURE

A) Preliminary

1. As per the given proportion, the quantities of cement, aggregate and water shall bedetermined by weight, to an accuracy of 0.1% of the total weight of the batch.

2. The quantity of concrete to be prepared shall be about 10 % excess of the volume of thedesired number of test specimens to account for losses.

3. The interior surfaces of the properly assembled mould shall be thinly coated with mouldoil to prevent adhesion of concrete.

4. The concrete shall be mixed by hand, or preferably, in a laboratory mixer machine, whichare described below.


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B) Mixing

1. Machine mixing

The sequence of materials to be fed into the hand-loaded concrete mixing machine is: it

shall be charged with about one-half of the coarse aggregate, then with the fine aggregate,

then with the cement, and finally with the remaining quantity of coarse aggregate on the top.

The water shall be added immediately before start rotating the drum. The period of mixing

shall not be less than two minutes and shall continue till the resulting concrete is uniform is

appearance.

2. Hand mixing

i) The cement and fine aggregate shall be mixed dry until the mixture is thoroughly blendedand is uniform in colour.

ii) The coarse aggregate shall then be added and mixed with the cement and fine aggregateuntil the coarse aggregate is uniformly distributed throughout.

iii)The water shall then be added and mixed until the concrete appears to be homogenousand has desired consistency.

C) Specimen preparation

1. Test specimens shall be made as soon as practicable after mixing. The concrete shall befilled in to the moulds in layers approximately 50 mm deep using hand scoop.

2. In placing each scoopful of concrete, the scoop shall be moved around the top edge of themould as the concrete slides from it, in order to ensure a symmetrical distribution of the

concrete within the mould.

3. Each layer of concrete can be compacted either by hand compaction or by vibration.4. After the last layer has been compacted with overflowing concrete, the surface may be

finished with trowel. By keep pressing the trowel, it may be moved forward and

backward to give additional compaction to the top layer concrete and the surface is also

finished simultaneously.

Cylinder specimens shall be capped with a thin layer of stiff and neat cement paste after

two to four hours of moulding.

5. After finishing the specimens, they shall be kept in moist air environment for 24 hours.After this period, the specimens shall be demoulded, marked and submerged in clean

water. Specimens shall be kept in water till testing at the appropriate ages.


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6. At the appropriate age the specimens are removed from water and surface water is wipedoff. The dimensions are measured and their weight shall be noted.

7. Immediately after finding the weight the specimens have to be tested before they becomedry. specimens shall not be tested in dry condition.

8. In the case of cubes, the specimen shall be placed in the Compression testing machinesuch that the load is applied through the sides of the cubes as cast and not through the top

and bottom.

9. The maximum (crushing) load applied to the specimen shall be recorded and any unusualfeatures noticed in the type of failure shall be reported.

FORMULA

Compressive strength = Crushing load

Cross sectional area

OBSERVATION

1) CubeLength = Breadth = Depth =

2) CylinderLength = Diameter =

TABULATION

(a) Cube strength

Sl.No Dateof casting

Dateof testing

Age oftest

Weight Density CrushingLoad

Compressivestrength

Unit Days kg kg/m3 kN N/mm2

Average


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(b) Cylinder strength

Sl.No Dateof casting

Dateof testing

Age oftest

Weight Density CrushingLoad

Compressivestrength

Unit Days kg kg/m3 kN N/mm2

Average

CALCULATION

(a) Cube compressive strength

(i) Fcu1 =

(ii) Fcu2 =

(iii) Fcu3 =


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(b) Cylinder compressive strength

(i) Fcy1 =

(ii) Fcy2 =

(iii) Fcy3 =

GRAPH

Plot the stress - strain curve with strain on X- axis and strain on Y- axis

RESULT

Compressive strength(i) Cube =(ii) Cylinder =


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AXIAL TENSION TEST TO OBTAIN STRESS - STRAINCURVE AND THE STRENGTH

Exp.No:

Date :

AIM

To conduct a tensile test on a mild steel specimen and determine the following:

1. Limit of proportionality2. Elastic limit3. Tensile yield strength4. Ultimate tensile strength5. Youngs modulus of elasticity6. Percentage of elongation

7. Percentage of reduction in area

EQUIPMENT

Universal testing machine, extensometer, meter scale, vernier, caliper and files.

THEORY

Within proportional limit the stress bears a constant ratio with strain. At yield point

the load indicating pointer stops for a moment, which signifies increase in strain under

constant stress. On further loading the ultimate load is reached which is indicated by the

pointer reading back. A necking is found to develop in the specimen at this load level.

PROCEDURE

1. The diameter of the rod is measured using vernier calipers at least at places and theaverage is taken.

2. The gauge length is calculated and marked on the specimen3. The specimen is gripped between the top and middle crosshead of the machine tightly

and the length of the rod between the grips is measured


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4. Extensometer is clamped on the specimen.5. Initial reading of the extensometer is noted.6. Adjust the machine for a suitable range.7. Load is gradually increased at convenient multiples and corresponding extensometer

readings are noted. When the elastic limit is reached the extensometer is removed.

8. The yield load, ultimate load and breaking loads are noted down.9. As soon as the rod fails, release the load.10.Fit the broken places together and measure the distance between the gauge length11. Measure the average diameter of the rod at broken end

OBSERVATION

1. Material

2. Original dimensions

Length = Diameter =

Area = d2

4

3. Final dimensions

Length = Diameter =

Area = d2

4

TABULATION

Diameter of specimen L.C. =

Sl.No M.S.R V.S.C V.S.R = V.S.C X L.C Corrected reading = M.S.R + V.S.R

Unit mm div mm mm


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Stress Vs Strain Reading

Sl No Load (P) Deformation () Stress () Strain (e) Youngs modulus (E)

Unit kN mm kN/mm2

No unit N/mm2

CALCULATION

Load at limit of proportionality

(i) Limit of proportionality =

Original area of cross section

Load at elastic limit

(ii) Elastic limit =



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Yield load

(iii) Yield strength =


Maximum tensile load

(iv) Ultimate strength =Original area of cross section

Stress below the proportionality limit

(v) Youngs modulus E =Corresponding strain

Final length (at fracture) - Original length(vi) Percentage of elongation =

Original length


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Original area - Area at fracture

(vii) Percentage reduction in area =

Original Area

GRAPH

Plot the stress - strain curve with strain on X- axis and strain on Y- axis

RESULT

(i) Limit of proportionality =

(ii) Elastic limit =

(iii)Yield strength =

(iv)Ultimate strength =

(v) Youngs modulus =

(vi)Percentage of elongation =

(vii) Percentage reduction in area =


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TORSION TEST ON MILD STEEL ROD

Exp.No:

Date:

AIM

To conduct torsion test on mild steel specimens to find out modulus of rigidity and

stiffness

EQUIPMENT

Torsion testing machine, Vernier caliper, mild steel specimen

THEORY

A torsion test is quite instrumental in determining the value of modulus of rigidity

(ratio of shear stress to shear strain) of a metallic specimen. The specimen is of cylindrical

steel with grooves on either side. An angel of twist of 1 is applied to the specimen and from

the torque applied the modulus of rigidity can be calculated.

PROCEDURE

1. Select the driving dogs to suit the size of the specimen and clamp it in the machine byadjusting the length of the specimen by means of a sliding spindle.

2. Measure the diameter at about three places and take the average value.3. Choose the appropriate range by capacity. Change lever.4. Set the maximum load pointer to zero.5. Set the protector to zero for convenience and clamp it by means of knurled screw.6. Carry out straining by rotating the hand wheel in either direction.7. Load the machine in suitable increments, observing and recording strain readings.8. Then load out to failure as to cause equal increments of strain reading.9. Plot a torque-twist (T - ) graph.10.Read off co-ordinates of a convenient point from the straight line portion of the torque-

twist (T - ) graph and calculate the value of G by using the relation.


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FORMULA

Torsion equationT/J = Fs / R = G / L

G = TL

JWhere T = Torque applied

J = Polar moment of inertia

G = Modulus of rigidity

= Angle of twist

L = Gauge length

OBSERVATION

Gauge length of the specimen L = mm

Diameter of the specimen, d = ..mm

Polar moment of inertia, J = d432

TABULATION

Sl

No

Torque Angle of twist 1 Angle of twist 2 Angle of

twist 1 ``2

Rigidity Modulus

Unit Nm Degree radian Degree radian radian N/mm2

Average


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CALCULATION

Rigidity modulus G = TL

J

(i)

(ii)

(iii)

GRAPH

Plot a torque-twist (T - ) graph with torque on X-axis and twist on Y-axis.

RESULT

Modulus of rigidity of the material of the specimen = -----------


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BENDING TEST

Exp.No:

Date:

AIM

Plot the load deflection curve to obtain Youngs modulus of the material using beam

simply supported at the ends carrying central concentrated load.

EQUIPMENT

Two knife edge supports, Dial gauge with magnetic stand, Deflect meter,

Load hanger, Weight, Steel beam, Vernier caliper

THEORY

The cross section of beam must strong enough to resist the bending and shear stress

which are produced by various loads. The max deflection must not exceed a given limit in

the beam. Then the stiffness of beam is inversely proportional to the second variation of

beam is measured at a resistance offered by the beam deflection stress its original position.

PROCEDURE

1. Adjust cast iron block along the bed. So that they are symmetrical with length of bed

2. Place the beam on the knife edges on the blocks. So as to project equally beyond

each knife. See that the load is applied at central position between the two supports

of the beam.

3. Note the initial reading of dial gauge by placing it in the central position between the

two supports of the beam.

4. Add a weight and again note the reading of dial gauge

5. Go on taking reading by adding weights in increments each time till maximum six

readings.

6. Find the deflection in each case.


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7. Draw a graph between load and deflection .Choose any convenient points and

between thus points find the corresponding values of weight and deflection

8. Calculate the value of E by using the given formula.

9. Calculate stress for difference loads as given in the table

FORMULA

Moment of inertia I = bd3

12

Where

I = Moment of inertia (mm4)

b = Breadth of beam (mm)

d = Depth of beam (mm)

Youngs modulus E = WL3

48 I

Where

W = load on beam (kg)

L = length of the beam (mm)

= Deflection (mm)

I = Moment of inertia ( mm4 )

OBSERVATION

Specimen =

Breadth of cross section (B) = .mm

Depth of cross section (D) = ..mm

Length of specimen (L) =mm


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TABULATION

SlNo

Type ofmaterial

Load(W)

Deflection( )

Mean deflection()

Youngs modulu(E)

Unit Kg N mm mm mm N/mm2

Average

CALCULATION

Youngs modulus E = WL3

48 I(i) E1 =

(ii) E2 =


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(iii) E3 =

(iv) E4 =

(v) E5 =

GRAPH

Draw a graph between load (W) and deflection (). On the graph choose any

two convenient points and between these points find the corresponding values of (W) and

(). Putting these values in the relation, E = WL the calculate value of E

48 IRESULT

For simply supported central loaded beam

Modulus of elasticity (E) = .


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7. Draw a graph between load and deflection .Choose any convenient points and between

thus points find the corresponding values of weight and deflection

8. Calculate the value of E by using the given formula.

9. Calculate stress for difference loads as given in the table

10. Repeat the experiment by changing the position of loading to the 2/3 position from the

left support of the beam and measure deflection at 1/3 position of the beam from left

support

11. Verify the values obtain for Maxwell reciprocating theorem (ie) the deflection must

be same for the same loading applied at different points

FORMULA

Placing the load at 1/3 position of length and the dial gauge at 2/3 position of the length

E= Wba (L2 - b2 - a2 )

6IL

Where a = Length of the 1/3 position of the beam from left support (mm)

(Position of load)

b = Length of the 2/3 position of the beam from left support (mm)

(Position of the dial gauge)

I = Moment of inertia (mm4)

W = load on beam (kg)

L = length of the beam (mm)

= Deflection (mm)

TABULATION

Case (i) 1/3rd load and 2/3 rd deflection

SlNo

Type ofmaterial

Load (W) Deflection() Meandeflection ()

Youngsmodulus (E)Loading Unloading

Unit Kg N mm mm mm 105N/mm

2


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Average

Case (ii) 1/3rd

deflection and 2/3rd

load

SlNo

Type ofmaterial

Load Deflection Meandeflection ()

Youngsmodulus (E)Loading Unloading

Unit Kg N mm mm mm N/mm2

Average

CALCULATION

Youngs modulus E = Wba ( L2 - b2 - a2 )

6IL

Case (i) 1/3rd

load and 2/3rd

deflection

(i) E1 =


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(ii) E2 =

(iii) E3 =

(iv) E4 =

(v) E5 =

Case (ii) 1/3rd

deflection and 2/3rd

load

(i) E1 =


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(ii) E2 =

(iii) E3 =

(iv) E4 =

(v) E5 =


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GRAPH

Draw a graph between load (W) and deflection (). On the graph choose any two

convenient points and between these points find the corresponding values of (W) and () for

both case (i) and case (ii). Putting these values in the relation E = Wba ( L2

- b2

- a2

)

calculate the value of E 6I L

From graph

(i) Stiffness K1 =

(ii) Stiffness K2 =

RESULT

Thus Maxwells Reciprocal theorem was verified. K1 = K2

COMPRESSION TEST ON OPEN COIL HELICAL SPRINGS

Exp.No:

Date:

AIM

To determine the stiffness of the spring, rigidity modulus of spring wire, spring index

of the given spring by applying the compressive force.

EQUIPMENT

Spring testing machine, Vernier caliper, Screw gauge, Open coil spring

THEORY

The hydraulic oil is filled in the oil tank, due to electrical power the oil pump

generator the oil which goes to the bottom of the cylinder .If the specimen is placed in

between the bottom and stationary cross heads forces will be compressive. If the specimen is

fixed in b/w the stationary and top cross heads, the force will be compressive the movement

of the piston is controlled by the control valve. The high pressure oil enters into bourdon


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pressure gauge causes the U tube and dial reads the reading in the pressure gauge. The

deflection of the spring can be taken from a scale for the corresponding loads.

PROCEDURE

1. Measure the spring coil diameter and spring wire diameter using vernier caliper and

screw gauge respectively

2. Count the no of coil is given spring

3. Place the open coil helical spring in between bottom cross heads and stationary cross

head

4. Switch on the electric motor and apply the force gradually on the spring by adjusting the

control valve

5. For each 25 Kg load, deflection was noted6. Calculate the spring stiffness, rigidity modulus and spring index by using formula

7. Draw the graph for load vs deflection compare the value with the theoretical value.

FORMULA

1. Spring stiffness K = w/ ( N/mm)

2. Deflection = 64 WR3 n sec [ cos2 + 2 sin 2 ] (mm)d4 G E

3. Shear stress T = 16 WR (N/mm2)

d3

4. Strain energy stored U = W

5. Spring index C = Dd

Where

W = load applied (N)

= Deflection, (mm)


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D = Coil diameter of the spring (mm)

d = Wire diameter of spring (mm)

Dm = Mean coil diameter (D m ) = (D - d) mm

N = No of turns of coil in the spring (Nos)

OBSERVATION

Diameter of coil (D) = mm

Diameter of spring (d) =..mm

No of turns (N) = mm

Applied load (W) =kg

Length (L) =mm

TABULATION

CALCULATION

Sl.No Cumulativedeflection

()

Actualdeflection

()

Load Mean load (P)

Loading Unloading

Unit mm mm N N N

Average


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From graph

(i) Stiffness W / =

(ii) Deflection = 64 WR3 n sec [ cos2 + 2 sin 2]d

4G E

(iii) Shear stress T = 16 WR

d3


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(iv) Strain energy U = W

(v) Spring Index C = Dd

GRAPH

Plot the graph between load and deflection, with load on X-axis and deflection on Y-axis

RESULT

1. Mean stiffness of spring ( R) =2. Rigidity modulus of spring =3. Shear stress =4. Strain energy stored =5. Spring Index =

TENSION TEST ON CLOSED COIL HELICAL SPRINGS

Exp .No.

Date:

AIM

To determine the stiffness of the spring rigidity modulus of spring wire spring index

of the given spring by applying the tensile force


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MATERIAL AND EQUIPMENT

1. Spring testing machine

2. Vernier caliper

3. Screw gauge

THEORY

The hydraulic oil is filled in the oil tank, due to electrical power the oil pump

generator the oil which goes to the bottom of the cylinder .This high pressure oil

inside the cylinder causes the piston to move up. When the piston moves up the

bottom and the top cross heads are also move up If the specimen is placed in

between the bottom and stationary cross heads. The deflection of the spring can

be taken from a scale for the corresponding levels

PROCEDURE

1. Measure the spring coil diameter and spring wire diameter using vernier

caliper and screw gauge respectively

2. Count the no of coil is given spring

3. Place the open coil helical spring in between bottom cross heads and

stationary cross head4. Switch on the electric motor and apply the force gradually on the spring by

adjusting the control valve

5. For each 25 Kg load, deflection was noted

6. Calculate the spring stiffness, rigidity modulus and spring index by using

formula

7. Draw the graph for load vs. deflection compare the value with the theoretical

value.

FORMULA

1. Spring stiffness K = w N/mm

2. Modulus of rigidity = 64 WR3 n N/mm2


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cd4

3. Shear stress = 16 WR N/mm2

d3

4 Strain energy stored U = W

5. Spring index C = D m

d

Where Wload applied (N)

Deflection, (mm)

DCoil diameter of the spring, mm

d- Wire diameter of spring, mm

nNo of turns of coil in the spring

OBSERVATION

Diameter of coil (D) =

Diameter of spring (d) =

No of turns (N ) =

Applied load (W) =

Length (L) =

TABULATION

Sl

No

Deflection Cumulative

()

Load(N)

Meanload

Rigiditymodulus

Stiffness(K)

Shearstress

Strainenergy

(cm) (mm) Loadingun

loading (N) N/mm2 N/mm N/mm2 N/mm


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MEAN

Result1. Mean stiffness of spring (R) =

2. Rigidity modulus of spring =

3. Shear stress =

4. Strain energy stored =

5. Spring Index =


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Exp. No

Date:

ROCKWELL HARDNESS TEST

AIM

To determine the Rockwell hardness number for hard and very hard materials.


Rockwell hardness testing machine, Specimen

THEORY

This test is used for finding the hardness of hard and very hard materials. For

hard materials like mild steel, Brass and Aluminium the indenter used is hard steel

ball indenter. The diameter of the ball in ball indenter is 1/16. The load applied forthese materials is 100kg and the time of application is 5 to 6 seconds. For very hard

materials like hardened steel and tool steel, diamond cone indenter is used. The apex

angle in cone indenter is 120. The cone is made of industrial diamond. The load to be

applied is 150 kg and the time of application is 6 to 8 seconds.

PROCEDURE

1. To be tested with 0.0. Emery paper2. Place the Specimen on the anvil of Polish the specimen the machine

3. Depending on the material of the specimen, select the indent and the

corresponding load

4. Rotate the avail and raise the worktable till the specimen is brought to contact and

mark the set position

5. Apply the load for the specified time after the pointer

6. Release the load, in the dial comes to rest and the Rockwell hardness number can

be directly read from the dial

7. Repeat the procedure to obtain two more sets of readings for each specimen

8. Take the average of three readings which gives the Rockwell hardness number


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OBSERVATION

(i) Thin steel - load 60 kgf , Diamond indenter(ii) Deep case hardened steel - load 150 kgf , Diamond indenter (iii)Malleable iron - load 150 kgf , 1 / 16 inch ball indenter

TABULATION

SlNo

Material Load applied Type ofindent

ScaleRockwellHardnessNumber

AverageRHN

Unit (Kg)

RESULT

Rockwell Hardness number

(i) Steel(ii) Brass(iii) Aluminium


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BRINELL HARDNESS TESTExp. No.

Date:

AIM

To find the surface hardness of the given specimen using Brinell hardness tester

EQUIPMENT

Brinell hardness testing machine, ball indenter, Brinell- Microscope

THEORY

The thickness of the test specimen shall not be less then a times the depth of the

indentation h Depth of indentation h=P / D x H B. Where P is applied in kg D =diameter of ball in mm. Edge distance = 2.3 times diameter of indentation. Distance

between the centers of two adjacent indentations = 4-6 times diameter of indentation

Test Load = 30 D2

- 15 D2

PROCEDURE

1. Polish the specimen with 0.0 emery paper2.

Place the Specimen on the anvil of the machine

3. Depending on the specimen material and the diameter of the ball indenter, selectthe proper load; Select a load of 3000kgf and a steel ball indenter of 10mm

diameter for hard material like steel .Select a load 1500kgf and a steel ball

indenter of 10mm diameter for soft material (Aluminium & brass). Duration of

loading is 10 seconds for hard material and 30 seconds for oft materials

4. Insert the ball indenter in the holder5. Rotate the anvil and bring the specimen in contact with the indenter6. Apply the load for the specified time7. Release the load and remove the specimen form the anvil8. Measure the diameter of the impression made by the indenter using Brinell

microscope

9. Repeat the same procedure and take two more readings for each specimen


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FORMULA

BHN = ____________P_______________D/2 (D- (D2-d2)

Applied load (in kg)

___________________________Surface area of indentation (inmm2)

Surface area of indentation = D/2 (D- (D2-d2)

Where D = Diameter of ball used in mm

d = diameter of indentation in mmP = load in kg

TABULATION

Material ofthe

specimen

Diameter of theindentation (d)

Averagediameter (d)

AppliedLoad (P)

Mean hardness

mm mm kg

Aluminium1

23

Brass1

2

3

Steel1

23

RESULT

Brinells Hardness number


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1. Steel =

2. Brass =

3. Aluminium =

VICKERS HARDNESS TEST

Exp. No.

Date :

AIM

To determine the Vickerss hardness number for the given specimen

EQUIPMENT

Vickers hardness testing machine, Diamond paint penetration

THEORY

The hardness-testing machine has a c shaped body. The lower part carries a

hand wheel, which is held in a thrust bearing. A spindle is screwed in the centre hole of

the hand wheel. The spindle is adjustable. The turret to which of the thrust piece and

the vertical illuminant of the projection as fastened is arranged above the table. The

thrust piece holds the penetration and the objective, is held in the vertical illuminant theobjective is exchangeable.

The eyepiece and the prison of the projection are screwed in the top of the

plunger. The hangers are fastened to the lever, with a fork. They consist of a rod with

the plate and the weights.

PROCEDURE

1. Polish the surface of the specimen.

2. Place the specimen on the supporting table.

3. Inset the penetration and Vickers diamond pyramid applicable to the test and the

derived load stage in the thrust piece.

4. Adjust the required load stage by actuating the corresponding push button.


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5. The lamp for the projecting device lights up.

6.Insert the standard hardness test specimen. Turn the hand wheel clockwise until thesurface of the specimen is sharply displayed on the focusing screen of the

measuring equipment.

7.Actuate the push button and do not release until the hand lower most upward. Thenreleases the push button waits the hand lever stops loading time in 30 sec.

8. When the period of force action is over, push the hand lever until the stop device

engages.

9. Now the impression can be measure using the measuring device.

10.Turn the measuring equipment so that the diagonal of the Vickers impression isparallel with the continues cross line of the scale of the measuring equipment.

11. As the magnification is 140 fold, the mean diagonal in mm will be, measurediagonal in mm divided by 2.

12.The Vickers hardness number can be found out using the table.

RESULT

The Vickers hardness of the given specimen is = ------------------


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DOUBLE SHEAR TESTExp. No.

Date :

AIM

To determine the shear strength of the given mild steel rod.

EQUIPMENT

Universal testing machine and double shear specimen.

PROCEDURE

1.The given specimen is cleaned well with 0-0 emery papers

2.The diameter of the rod is measured using vernier caliper at three places.

3.The shear box consists of a sliding block which is used to shear the specimen. The

suitable die is chosen depending on the diameter of the specimen and is tested in the

shear box.

4.The specimen is held inside the dies in position.

5.The whole set-up is placed in the Universal testing machine and a compressive load

is applied.

6.When the compressive load is applied on the sliding block of the shear attachment, it

will shear the specimen along two parallel planes.

7.Note shear strength of specimen is given byShear Strength = Failure load

2 x Area of cross section

FORMULAPu

1. Ultimate shear stress =

2A

P u = Ultimate load (N)

A = Cross sectional area (m2)


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2. Breaking shear stress = P b

2 A

P b = breaking load in N

A = Cross sectional area (m2)

OBSERVATION

Average diameter of the rod = .. mm

Area of cross section of the rod = mm2

Failure load = kgf

TABULATION

Sl.No M.S.R V.S.C V.S.R = V.S.C X L.C Corrected reading = M.S.R + V.S.R

Unit mm div mm mm

SI.NoDia ofSpecimen

(d)

Area ofspecimen

(A)

Ultimateload(Pu)

Breakingload(Pb)

Ultimate shearstrength

(Fu)

Breaking shearstrength

(Fb)

Unit mm mm2 kN kN kN/mm

2 kN/mm2


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CALCULATION

1) Ultimate shear stress Fu = Pu

2A

i) Fu =

ii) Fu =

2) Breaking shear stress = Pb

2A

i) Fb =

ii) Fb =

RESULT:

1. The ultimate shear stress of the Mild steel specimen = N/mm2

2. The breaking shear stress of the Mild steel specimen =.. N/mm2


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IMPACT TEST

A) CHARPY IMPACT TEST

Exp. No.

Date :

AIM

To determine the impact strength ( Charpy Specimen) of a given specimen.


Impact testing machine, standard impact strength specimen

THEORY

The modes of failure observed under conditions of loads can be classified as

(I) Brittle (II) Ductile (III) Intermediate. Most of the materials exhibits change from

ductile to brittle behaviour, which occurs at a transition temperature. This

embrittlement of the material can be accessed by this impact test.

PROCEDURE

1. Set the pointer to the maximum reading of the dial.

2. Release the lock and allow the pendulum to swing.

3. Record the energy absorbed due to friction, which is indicated by the pointer on

the dial. Call it A.

4. Lock the pendulum in its original position.

5. Keep the specimen truly horizontal in the vice such that the notch in the specimen

is kept on the opposite side of the blow.

6. Release the lock and allow the striking edge of the pendulum to strike the

specimen.


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CALCULATION

Ik = B-A

a

PRECAUTIONS

1. Pendulum must swing freely over the horizontal axis of rotation.2. Friction Efforts must be accounted.3. Operator should not stand inside the swinging zone of the

pendulum.

4. Only standard pendulum must be used.

RESULT

1. Impact strength of the given specimen = .. J/mm2.2. Report on the nature of the fracture surface.


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IMPACT TEST

B) IZOD IMPACT TEST

Exp. No.

Date

AIM

To determine the impact test of a given specimen.


Impact testing machine, Izod Specimen

THEORY

The modes of failure observed under conditions of loads can be

classified as (I) Brittle (II) Ductile (III) Intermediate. Most of the materials exhibits

change from ductile to brittle behavior, which occurs at a transition temperature. This

embrittlement of the material can be accessed by this impact test.

PROCEDURE

1. Set the pointer to the maximum reading of the dial.

2. Release the lock and allow the pendulum to swing.

3. Record the energy absorbed due to friction, which is indicated by the pointer on

the dial. Call it A.

4. Lock the pendulum in its original position.

5. Keep the specimen truly horizontal in the vice such that the notch in the specimen

is kept on the opposite side of the blow.

6. Release the lock and allow the striking edge of the pendulum to strike the

specimen.

7. The reading shown (Call it B) in the dial is the energy absorbed by the specimen,

which includes the energy absorbed due to friction.

8. Therefore, actual strain energy absorbed by the specimen equals BA

Strain energy absorbed


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SPECIFIC GRAVITY OF CEMENTExp. No.

Date :

AIM

To determine specific gravity of cement sample

EQUIPMENT AND MATERIAL REQUIRED

Specific gravity bottle, Kerosene fix from water, Weighing balance

THEORYIn concrete technology, specific gravity of cement is made use of in design

calculations of concrete mixes, and it is also used to calculate its specific surface. The

specific gravity is defined as the ratio between the weight of a given volume of

cement and weight of an equal volume of water. The most popular method of

determining, S.G. of cement is by the use of kerosene which doesnt react with

cement

PROCEDURE

1. Weigh the specific gravity bottle dry (W1)2. Fill the bottle with distilled water and weigh the bottle(W2)3. Dry the specific gravity bottle and fill it with kerosene and weigh(W3)4. Pour some of the kerosene out and introduce a weighed quantity of cement ( say

about 60 gms) into the bottle. Roll the bottle gently in the inclined position until no

further air bubble rise to the surface. Fill the bottle to the top with kerosene and

weight it(W4)

OBSERVATION

1. Weight of empty dry bottle (W1) = gms

2. Weight of bottle + water (W2) = gms

3. Weight of bottle + kerosene (W3) = gms

4.Weight bottle + cement + kerosene(W4) = gms


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5. Weight of cement (W5) = gms

CALCULATION

Specific gravity of kerosene g = W3 -W1

W2 - W1

Specific gravity of cement G = W5 (W3 - W2)

( W5+W3-W4 ) (W2 - W1 )

G = W5

x g

(W5+W3-W4)

RESULTSpecific gravity of cement=


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SETTING TIME OF CEMENTExp No.Date :

AIM

To find out the initial setting time cement.


1. Vicat apparatus with all its accessoriesTHEORY

In actual construction dealing with cement paste, mortar , concrete , certain

time is required for mixing, transporting and placing. During this time the cement

mixture should be in plastic condition. The time interval for which the cement

products remain in plastic condition is known as setting time. Normally a minimum

of 30 minutes called initial setting time and maximum of 10 hours called final setting

time for OPC

PROCEDURE

1. Before doing I.S.T , F.S.T , normal consistency , (p) of cement paste is required

NORMAL CONSISTENCY

1. Take 400gms cement and prepare a paste with a weighed quantity of water (say 24%)

2. Fill the paste in the mould with in 3 to 5 minutes3. Shake the mould to expel air4. A standard plunger 10mm dia , and 50 mm long is attached and brought down to

touch the surface of the paste in the test block and quickly release it to sink in to the

paste by its own weight5. Note down the depth of penetration of the plunger6. Conduct the second trail (25% of water ) and find out the depth of penetration.7. Conduct number of trails till the plunger penetrates for s depth of 33 35mm from

top


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8. The particular percentage of water which allows the plunger to penetrate to a depthof 3335mm is known as the % of water required to procedure a cement paste of

standard consistency

INITIAL SETTING TIME

1. Prepare a neat cement paste with 0.85 times the water required to give a standardconsistency

2. Note down the time at which the water is added3. Fill the vicat mould with the cement paste with in 3- 5 minutes4. Smooth the surface of the paste , making it level with the top of the mould5. Lower the needle gently into the surface of the paste and quickly released allowing it

to sink into the paste by its own weight

6. Repeat the procedure until the needle fails to pierce the block for above 5mm 7mmmeasure from the bottom and note down the time in stop watch

7. The difference between the two timings will give the initial setting time.

OBSERVATION

NORMAL CONSISTENCY

Needle used plunger size 10mm x 5mm

Sl.No

Weight of cement Percentage ofwater

Amount ofwater

Reading of thepointer from

bottom


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INITIAL SETTING TIME

Needle used = Needle with 1 sq. mmAmount of water = 0.85 P.

Sl.No

Time in minutes Reading of the pointer

FINAL SETTING TIME

Needle used = Needle with a circular attachment

RESULTInitial setting time of cement


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COMPRESSIVE STRENGTH CEMENTExp No.Date :

AIMTo determine the compressive strength of the given cement


Mould of size 7.06 cm x 7.06cm , Wide base plate , C.T.M

THEORY

Strength of the hardened cement is most important for structural use . This

strength depends upon the cohesion of the cement paste on its adhesion to the

aggregate particles. Several forms of this test are direct tension , compression and

flexure. This strength depends upon the temperature and humidity conditions of the

room, curing chamber etc. It increases with age, strength retrogression might be a

sign of unsoundness or other faults in cement

PROCEDURE

1. Find out the consistency of the given cement by using Vicat apparatus2. take 555g of standard sand ( Ennore sand ) and 185 gms cement (ie) ( C : m) in

ratio 1:3

3. Mix them in a nonporous enamel tray for one minute4. Then add water of quantity P + 3 % of combined weight of sand and

4

Cement . ( where p-percentage water required for standard consistency)

5. Mix well to get a uniform colour.6. Time of mixing should not be less than 3 minutes not more than 4 minutes7. Then fill the mould of size 7.06cm8. Compact the mortar by hand compaction in a standard manner9. Keep the compacted cube in the mould at a temperature 27 + 2 C for 24

hours


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10.After 24 hours the cubes are removed from the mould and immersed in clean freshwater.

11.Then these cubes are tested for compressive strength at the periods mentionedbelow

(OPC) Ordinary Portland cement = 3 & 7 days

(RHC) Rapid Hardening cement = 1 & 3 days

(LHC) Low heat cement = 3, 7 & 28 days

This average compressive strength shall not be less than the values given in the table

SlNo

Duration oftime

OPC RHC LHC

Unit kg/cm2

kg/cm2

kg/cm2

1. 1 day 24 hours - 160 -

2. 3days (72 hrs) 160 275 100

3. 7days (178hrs) 220 - 160

4. 28days(672hrs) - - 350

OBSERVATION

Size of the mould =

Weight of cement =

Weight of sand =

Percentage of water for standard consistency =

Amount of water added = P + 3 %

4


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Sl.No

Cast on Tested on Failure load Compressivestrength

CALCULATION

Area of the mould =

Compressive strength = Load at failure

Area

=

=


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RESULT

Compressive strength of cement =

SOUNDNESS TEST

Exp No.

Date.

AIMTo detect unsoundness in cement


Le-chatlier mould with all its accessories

THEORY

Un soundness in cement is due to the presence of excess of lime,

magnesia or sulphates . Because of this it undergoes an appreciable change in

volume after setting. The testing of soundness of cement to ensure that the

cement does not show any appreciable subsequent expansion

PROCEDURE

1.Mix cement thoroughly with 0.78p (where p is the percentage of water

required for standard consistency)

2.Fill the Le-chatlier mould kept on a glass plate.

3.Cover the mould on the top with another glass plate

4.Immerse the whole assembly in water at 27 32 C for 24 hours

5.Measure the distance between the indicator points

6.Submerge the mould again in water

7.Heat the water and bring to boiling point in 25-30 minutes and keep it

boiling for 3 hours

8.Remove the mould from the water, allow it to cool and measure the distance

between the indicator points.

9.This must not exceed 10 mm.


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OBSERVATION

Weight of cement =

Water required for standard consistency =

Amount of water added =

Distance between the indicator points

Before boiling =

After boiling =

RESULTUnsoundness in cement


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MECHANICAL PROPERTIES FOR

UNHARDENED OR HARDENED SPECIMEN

Exp. No.

Date :

AIMTo find hardness number and impact strength for unhardened, hardened

specimen or Quenched and tempered specimen and compare mechanical properties.


Unhardened specimen, Hardened or Quenched and tempered specimen, muffle

furnace, Rockwell testing machine, impact testing machine.

PROCEDURE

Case (i) - Unhardened specimen

Choose the indenter and load for given material.

Hold the indenter in indenter holder rigidly

Place the specimen on the anvil and raise the elevating screw by rotating the

hand wheel upto the initial load of 10 kgf (i.e. short hand and long hand

showed read 3

Apply the major load gradually by pushing the lever and then release it as

before.

Note down the readings in the dial for corresponding scale.

Take min 5 readings for each material.

Case (ii) - For unhardened specimen

Keep the specimen in muffle furnace at temperature of 700 to 850 for 2 hours

The specimen is taken from muffle furnace and quenched in water or oil


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Then above procedure is followed to test hardness

Case (iii) - For Tempered specimen

Keep the specimen in muffle furnace at temperature of 650 for 2 hours

Allow the specimen for air cooling after taking from muffle furnace

Then same procedure is followed foe the specimen

OBSERVATION

Cases for hardness =

Cross sectional area =

SI.No Material SelectedTemperature

(C)

SelectedLoad

(N)

Indenterdetail

Scale RHN

Trial1

Trail2

Trail3

Mea

1 Deep caseHardened steel

2. Deep caseHardened steel

3. Mild steel

4. Mild steel


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CHARPY TEST

SI.No Material and Condition Energy

absorbed

Cross-sectional area

below the notch

Impact stren

Unit Jouls mm2

J/ mm2

1. Mild steel-unhardened

2. Quenched

RESULT

1. Hardness in(i) Deep case hardened steel

(a) Unhardened

(b) Quenched

(ii) Mild steel

(a) Unhardened

(b) Quenched

2. Impact strength in

(i) Deep case hardened steel


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(a) Unhardened

(b) Quenched

BEHAVIOR OF BEAM UNDER BENDING

Exp. No.

Date :

AIM

To verify strain in an externally loaded beam with the help of a strain gauge

indicator and to verify theoretically.

APPARATUS

Strain gauge indicator, weights , hanger , scale , verniar caliper

FORMULA

f = M yI

THEORY

When a beam is loaded with some external loading, moment & shear force are

set at each strain. The bending moment at a station tends to deflect the beam &

internal stresses tend to resist its bending. This internal resistance is known as

bending stresses .

Following are the assumptions in theory of simple bending.


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1. The material of beam is perfectly homogeneous and isotropic (i.e have same elasticproperties in all directions)

2. The beam material is stressed to its elastic limits and thus follows Hooks law3. The transverse section which are plane before bending remains plane after bending

also

4. The value of youngs modulus of elasticity E is same in tension and compressionThe bending stress at any section can be obtained by beam equation

f = (M/ I) y

Where , M = moment at considered section

f = Extreme fiber stresses at considered section

I = Moment of inertia at that section

y = Extreme fiber distance from neutral axis

fmax = maximum stress at the farthest fiber i.e. at ymax from neutral axis

Digital strain indicator is used to measure the strain in static condition . It

incorporates basic bridge balancing network , internal dummy arms , an amplifier anda digital display to indicator strain value

In resistance type strain gauge when wire is stretched elastically its length and

diameter gets altered. This results in an overall change of resistance due to change in

both the dimensions. The method is to measure change in resistance , which occurs as

a result of change in the applied load

Strain can be calculated analytically at the section by using Hooks law. Distrain

indicator is used to measure the extreme fiver at particular section. It basically

incorporates basic bridge balancing net work, internal dummy arms , amplifier &

digital display to indicate strain value


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Two - Arm bridge requires two strain gauge and will display the strain value two

times of actual . Four - Arm bridge requires four strain gauge and will display the

strain value four times of actual

PROCUDURE

1. Mount the beam with hanger , at the desired position and strain gauges , over itsupports properly and connect the strain gauges to the digital indicator as per the

circuit diagram.

2. Connect the digital indicator to 230(+/- 10% ) colts 50 Hz single phase A.C powersupply and switch ON the apparatus

3. Select the two / four arm bridge as required and balance the bridge to display a000 reading

4. Push the GS READ switch and adjust the gauge factor to that of the straingauge used (generally 2.00)

5. Apply load on the hanger increasingly and note the corresponding strain value

OBSERVATION TABLE

Sl.No Load appliedon the

hanger P

Moment at themid spansection

f max =(M/I)Ymax

Theoreticalstrain =

fmaxE

Observedstrain on

the display

Unit kg (kg cm) = PL/4

SAMPLE CALCULATION

For reading No ____________

Load applied on the hanger P (kg)

Moment at the mid span section (kg cm )= PL/4


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f max = (M/I) Y max

Theoretical strain = fmax

E

Observed strain on the display

RESULT

From observation table , it is seen that , the theoretical and observed value of strain issame.

MT LabMANUAL

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