INDEX

S.NO. PRACTICAL TO PERFORM REMARK

1. To determine the crushing value of aggregate.

2. To determine 10% finer value of aggregates.

3. (i) To determine the abrasion value of aggregate by Los Angeles apparatus.

(ii) To find the suitability of aggregates for use in road construction.

4. Determination of impact value of aggregate.

5. To determine optimum binder content of given bituminous mix by marshall method of mix design.

6. To determine the flash and fire point of a given bituminous material.

7. To determine the Elongation index of the given aggregate sample.

8. To determine the flakiness index of a given aggregate sample.

9. To determine the softening point of bitumen.

10. To measure the ductility of a given sample of bitumen

11. To determine the viscosity of bituminous binder.

12. 1. Determination of abrasion value by Deval’s Abrasion Machine.

1

EXPERIMENT NO-

AIM To determine the crushing value of aggregate.EQUIPMENT The apparatus for the standard aggregate crushing test

consists of the following:(i) Steel cylinder with open ends, and internal diameter

15.2 cm, square base plate plunger having a piston of diameter 15cm with a hole provided across the stem of the plunger so that a rod could be inserted for lifting or placing the plunger in the cylinder.

(ii) Cylindrical measure having internal diameter of 11.5 cm and height 18 cm.

(iii) Steel temping rod with one rounded end, having a diameter of 1.6 cm and length 45 to 60 cm

(iv) Balance of capacity 3 kg with accuracy up to 1 g.(v) Compressions testing machine capable of applying load

of 40 tonnes, at a uniform rate of loading of 4 tonnes per minute.

FIGURE:

THEORY The principal mechanical properties required in road stones are

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(1) Satisfactory resistance to crushing under the roller during construction and,

(2) Adequate resistance to surface abrasion under traffic.

Also surface stresses under rigid tyre rims of heavily loaded animal, drawn vehicles ate high enough to consider the crushing strength of road aggregates as an essential requirement in India.

Crushing strength of road stones may be determined either on aggregates or on cylindrical specimens cut out of rocks. These two tests are quite different in not only the approach but also in the expression of the results.

Aggregates used in road construction, should be strong enough to resist crushing under traffic wheel loads If the aggregates are weak, the stability of the pavement structure is likely to be adversely affected. The strength of coarse aggregates is assessed by aggregates crushing test. The aggregate crushing value provider. a relative measure of resistance to crushing under a gradually applied compressive load. To achieve a high quality of pavement, aggregate possessing low aggregate crushing value should be preferred.

PROCEDURE 1. The aggregate passing 12.5 mm IS sieve and retained on 10 mm IS sieve selected for standard test.

2. The aggregate is dried by heating at a temperature 1000 c to 1100 c for a period of 4 hours .

3. The cylindrical measure is filled by the test sample of aggregate in three layers of approximately equal depth, each layer being tamped 25 times by the rounded end of the tamping rod.

4. After the third layer is tamped. the aggregates at the top of the cylindrical measure is levelled off by using the tamping rod as a straight edge.

5. Take 6.5 kg of aggregate for preparing two test samples .6. The same weight of the sample is taken in the repeat test.7. The cylinder of the test apparatus is placed in position on

the base plate; one third of the test sample is placed in this cylinder and tamped 25 times by the tamping rod.

8. Similarly, the other two parts of the test specimen are added, and each layer being subjected to 25 blows.

9. The total depth of the material in the -cylinder after tamping shall however be 10 cm.

10.The surface of the aggregates is levelled and the plunger

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inserted so that it rests on this surface in level position.11.Load is then applied through the plunger at uniform rate of 4

tonnes per minute until the total load is 40 tonnes, and then the load is released.

12.Aggregates including the crushed portion are removed from the cylinder and sieved on a 2.36 mm IS sieve and the material which passes this sieve is collected.

13.The above crushing test is repeated on second sample of the same weight in accordance with above test procedure. Thus two tests are made for the same specimen for taking an average value.

OBSERVATION TABLE:-

SL. NO.

SAMPLE NO. Total Weight of the dry sample taken (W1) gms.

Weight of the portion of crushed material passing 2.36 mm IS sieve (W2) gms.

Aggregate Crushing Value =

1. V1=

2. V2=

Average crushing value of aggregate = =

CALCULATION Total Weight of the dry sample taken = W1 gms.Weight of the portion of crushed material passing 2.36 mm IS sieve = W2 gms.

The aggregate crushing value is defined as a ratio of the weight of fines passing the specified IS sieves to the total weight of the sample, expressed as a percentage. The value is usually recorded up to the first decimal place.

Aggregate crushing value = 100W2/W1

RESULT The mean of the crushing value obtained in the two tests is reported as the aggregate crushing value ______________.

PRECAUTIONS 1. The aggregate should be in surface-dry condition before

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testing.2. The test sample is weighed accurately.3. The cylinder of the test apparatus should be placed in

accurate position on the base plate.4. Loads should be applied at uniform time intervals.5.

PROBLEMS 1. How is the crushing strength test carried out on cylindrical stone specimen? Why is this test not carried out commonly?

2. What is the specified standard size of aggregates? How is the aggregate crushing value of non-standard size aggregate evaluated?

3. What are the uses and applications of aggregate crushing test?

4. What are the recommended maximum values of aggregate crushing value for the aggregate to be used in base and surface course of cement concrete?

5. Aggregate crushing value of material A is 40 and that of B is 25. Which one is better and why?

EXPERIMENT NO-

AIM To determine 10% finer value of aggregates.

5

EQUIPMENT The apparatus for the standard aggregate crushing test consists of the following:

(i) Steel cylinder with open ends, and internal diameter 25.2 cm, square base plate plunger having a piston of diameter 15cm with a hole provided across the stem of the plunger so that a rod could be inserted for lifting or placing the plunger in the cylinder.

(ii) Cylindrical measure having internal diameter of 11.5 cm and height 18 cm.

(iii) Steel temping rod with one rounded end, having a diameter of11.6 cm and length 45 to 60 cm

(iv) Balance of capacity 3 kg with accuracy up to 1 g. ( v) Compressions testing machine capable of applying load of 40 tonnes, at a uniform rate of loading of 4 tonnes per minute.

FIGURE:

THEORY Ten percent fines value is a measure of the resistance of aggregate crushing subjected to loading and it is applicable to both weak and

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strong aggregate.

Fine aggregates are defined as those passing 2.36mm sieve.

The test aims at looking for the forces required to produce 10% of fine values (i.e. weight of fines aggregates/weight of all aggregates = 10%).

This test is very similar to Aggregate Crushing Test in which a standard force 400kN is applied and fines material expressed as a percentage of the original mass is the aggregate crushing value.

Granular sub-base is subjected to repeated loadings from truck types. The stress level at the contact points of aggregate particles is quite high. The sub-base in pavement is a structural layer used for distribution of traffic loads into larger area. As such, it is of paramount importance that the sub-base material should itself not be disintegrated under severe traffic loads. Ten percent fines value can be used to reveal the aggregate.

PREPARATION OF TEST SAMPLE

1. The material for the test shall consist of aggregate passing a 12.5 mm IS Sieve and retained on a 10 mm IS Sieve and shall be thoroughly separated on these sieves before testing.

2. The aggregate shall be tested in a surface-dry condition. If dried by heating, the period of drying shall not exceed four hours, the temperature shall be 100 to 110°C and the aggregate shall be cooled to room temperature before testing.

3. The quantity of aggregate shall be such that the depth of material in the cylinder after tamping as described in step-4,

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shall be 10 cm.

4. The appropriate quantity may be found conveniently by filling the cylindrical measure in three layers of approximately equal depth, each layer being tamped 25 times with the tamping rod and finally levelled off, using the tamping rod as a straight-edge, care being taken in the case of weaker materials not to break the particles.

5. The weight of material comprising the test sample shall be determined (Weight A) and the same weight of sample shall be taken for the repeat test.

PROCEDURE 1. Test Procedure-The cylinder of the test apparatus shall be put in position on the base-plate and the test sample added in thirds, each third being subjected to 25 strokes from the tamping rod, care being taken in the case one weak materials not to break the particles. The surface of the aggregate shall be carefully levelled and the plunger inserted so that it rests horizontally on this surface, care being taken to ensure that the plunger does not jam in the cylinder.

2. The apparatus, with the test sample and plunger in position, shall then be placed in the compression testing machine. The load shall be applied at a uniform rate so as to cause a total penetration of the plunger in 10 minutes of about :

a. 15.0 mm for rounded or partially rounded aggregates (for example, uncrushed gravels).

b. 20.0 mm for normal crushed aggregates, andc. 24.0 mm for honeycombed aggregates (for example,

expanded shales and slag). These figures may be varied according to the extent of the rounding or honeycombing.

3. After reaching the required maximum penetration, the load shall be released and the whole of the material removed from the cylinder and sieved on a 2.36 mm IS Sieve. The fines passing the sieve shall be weighed, and this weight expressed as a percentage of the weight of the test sample. Normally, this percentage will fall within the range 7.5 to 12.5, but if it does not, a further test shall be made at a load adjusted as seems appropriate to bring the percentage fines within the range of 7.5 to 12.5.

4. A repeat test shall be made at the load that gives a percentage

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fines within the range 7.3 to 12.5.

OBSERVATION TABLE:-

SL. NO. SAMPLE NO. Total Weight of the dry sample taken (W1)

gms.

Weight of the portion of crushed material passing 2.36 mm IS sieve (W2) gms.

Percent fines =

1. V1=

2. V2=

Percentage fines (Y) = =

CALCULATION The mean percentage fines from the two tests at this load shall be used in the following formula to calculate the load required to give 10 percent fines:

Load required for ten percent fines =

Where x = load in tonnes, and y = mean percentage fines from two tests at x tonnes load.

RESULT The load required to produce 10 percent fines shall be reported to the nearest whole number for loads of 10 tonnes or more, the nearest 0-5 tonnes for loads of less than 10 tonnes.

PRECAUTIONS 1. The aggregate should be in surface-dry condition before testing.

2. The test sample is weighed accurately.3. The cylinder of the test apparatus should be placed in

accurate position on the base plate.4. Loads should be applied at uniform time intervals.5.

PROBLEMS 1. How will you determine Ten percent fines value?

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2. What are the uses and applications of aggregate Ten percent fines value?

EXPERIMENT NO-10

AIM (iii) To determine the abrasion value of aggregate by Los Angeles apparatus.

(iv) To find the suitability of aggregates for use in road construction.

EQUIPMENT The apparatus as per IS: 2386 (Part IV) – 1963 consists of:

(i) Los Angeles Machine: It consists of a hollow steel cylinder, closed at both the ends with an internal diameter of 700 mm and length 500 mm and capable of rotating about its horizontal axis. A removable steel shaft projecting radially 88 mm into cylinder and extending full length (i.e.500 mm) is mounted firmly on the interior of cylinder. The shelf is placed at a distance 1250 mm minimum from the opening in the direction of rotation.

(ii) Abrasive charge: Cast iron or steel balls, approximately 48mm in diameter and each weighing between 390 to 445g; six to twelve balls are required.

(iii) Sieve: 1.70, 2.36,4.75,6.3,10,12.5,20,25,40,50,63,80 mm IS Sieves.

(iv) Balance of capacity 5kg or 10kg.

(v) Drying oven.

(vi) Miscellaneous like tray.

FIGURE:

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THEORY The aggregate used in surface course of the highway pavements are subjected to wearing due to movement of traffic. When vehicles move on the road, the soil particles present between the pneumatic tyres and road surface cause abrasion of road aggregates. The steel reamed wheels of animal driven vehicles also cause considerable abrasion of the road surface. Therefore, the road aggregates should be hard enough to resist abrasion. Resistance to abrasion of aggregate is determined in laboratory by Los Angeles test machine.

The principle of Los Angeles abrasion test is to produce abrasive action by use of standard steel balls which when mixed with aggregates and rotated in a drum for specific number of revolutions also causes impact on aggregates.

The percentage wear of the aggregates due to rubbing with steel balls is determined and is known as Los Angeles Abrasion Value.

RECOMMENDED VALUE:

Los Angeles test is commonly used to evaluate the hardness of aggregates. The test has more acceptability because the resistance to abrasion and impact is determined simultaneously. Depending upon the value, the suitability of aggregates for different road constructions can be judged as per IRC specifications as given:

PROCEDURE The test sample consists of clean aggregates dried in oven at 105° – 110°C. The sample should conform to any of the gradings shown in table 1.

(i) Select the grading to be used in the test such that it conforms to the grading to be used in construction, to the maximum extent possible.

(ii) Take 5 kg of sample for gradings A, B, C & D and 10 kg for gradings E, F & G.

(iii) Choose the abrasive charge as per Table 1 depending on

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grading of aggregates.

(iv) Place the aggregates and abrasive charge on the cylinder and fix the cover.

(v) Rotate the machine at a speed of 30 – 33 revolutions per minute. The number of revolutions is 500 for gradings A, B, C & D and 1000 for gradings E, F & G. The machine should be balanced and driven such that there is uniform peripheral speed.

(vi) The machine is stopped after the desired number of revolutions and material is discharged to a tray.

(vii) The entire stone dust is sieved on 1.70 mm IS sieve.

(viii) The material coarser than 1.7mm size is weighed correct to one gram.

OBSERVATION TABLE:-

TABLE 1

Gra

din

g

Weight in grams of each test sample in the size range, mm

(Passing and retained on square holes.)

Number of spheres

Weight of charge, (g)

80-63 63-50 50-40 40-25 25-20 20-12.5 12.5-10 10-6.3 6.3-4.75 4.75-2.36

A 1250 1250 1250 1250 12 5000+25

B 2500 2500 11 4584+25

C 2500 2500 08 3330+25

D 5000 06 2500+25

E 2500* 2500* 5000* 12 5000+25

F 5000* 5000* 12 5000+25

G 5000* 5000* 12 5000+25

Tolerance of + 2 percent is permitted

CALCULATION Let original weight of aggregate sample = W1 g

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Weight of aggregate sample retained on 1.70 mm IS sieve after the test = W2 g

Loss in weight due to wear = (W1 - W2) g

Abrasion Value or Percentage wear = ((W1 - W2 ) / W1) X 100 %

RESULT Los Angeles Abrasion Value =

PRECAUTIONS 1.2.3.4.5.

PROBLEMS 1. How is Los Angeles abrasion value expressed?2. What are the desirable limits of los angeles abrasion

values specified for different types of pavement surfacing?3. Briefly explain the Los Angeles abrasion test procedure.

14

EXPERIMENT NO-

AIM Determination of impact value of aggregateEQUIPMENT 1. Impact testing machine,

2. Weighing balance,3. Weight box,4. Tamping rod,5. 2.36mm IS sieve etc.

FIGURE:

IMPACT VALUE APPARATUS

THEORY Aggregate impact Value: - With respect to concrete, aggregate toughness is usually considered the resistance of the materials to failure by impact. The most successful is the one in which a sample of standard aggregate kept in mould is subjected to 15 blows of a metal rammer of weight 14 Kg. falling from a height of 38cms. The quantity of materials passing through 2.36mm IS sieve will indicate the toughness of the sample of aggregate.

The ratio of the weight of the weight of total sample taken in expressed as a percentage this is known as aggregate impact value. IS 283- 1970 specified that aggregate impact value shall not exceed 45% by weight for aggregate used for concrete other than wearing surface and 30% by wearing for concrete for wearing surface, such as runways, roads and pavement.Aggregates are classified for type and user in the following according to their impact value.

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Impact Value.SL.NO. Impact Value Aggregate Classification1 Below 10 Exceptionally strong aggregate2 10-20 Strong3 20-30 Satisfactory for road surfacing4 Greater than

30Used for road surfacing

5 Max limit in 30

For bituminous & cement concrete

6 35 For bituminous

FORMULA–Impact Value = W3 / (W2 – W1) X100Where,W1 = Empty wt of cylinder.W2= Wt of Cylinder + aggregate.W3= Wt of fines passing through 2.36 mm sieve

PROCEDURE 1. Take the test sample consisting of standard aggregate passing through 12.5mm and retained on 10mm I.S. sieves. The aggregate about one third full of the mould and tamped by 25 strokes by tamping rod. Add further similar quantity of aggregate and tamp it and fill the measure.

2. Determine the net wt of aggregate in mould.3. Place the whole sample into a steel cylindrical cup

fixed on the base of the machine.4. Raise the hammer wt about 14kgs to the height of

38cm above the surfaces of aggregate.5. The sample was subjected to a total 15 such blows

each derived at an interval of not less than one sec.6. Remove the crushed aggregate from the cup and

sieve through 2.36mm 1S sieve and weight the material passed through 2.36mm.

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OBSERVATION TABLE:-

SL.NO. Details TRIAL NUMBER AVERAGE

1 2 3

1 Empty weight of the cylinder = W1 gm

2 Weight of aggregate + Cylinder = W2 gm

3 Weight of fines passing through 2.36mm sieve after the test = W3 gm

4 Weight of aggregate for test sample = W2 – W1 gm

5 Aggregate Impact Value

= {W3/(W2 – W1)}×100

CALCULATION Impact Value = {W3/(W2 – W1)}×100RESULT The impact value of given sample of aggregate found out

to be__________.

PRECAUTIONS 1. The aggregate used should be of good quality.(2. Hammer should be properly handed otherwise it may cause physical damage or injury.3. 4.5.

PROBLEMS 1. How is aggregate value expressed?2. What are the desirable values of agg. Impact value for different types of pavement surface?

17

EXPERIMENT NO-

AIM To determine optimum binder content of given bituminous mix by marshall method of mix design.

EQUIPMENT Mould assembly, sample extractor, compaction pedestal and hammer, breaking head, loading machine flow meter, thermometers water bath and oven

FIGURE:

THEORYPROCEDURE 1. The coarse aggregates, fine aggregates and mineral filler

material should be proportioned and mixed in such a way that final mix after blending has the graduation within the specified range.

2. Approximately 1200 grams of aggregates and filler are taken and heated to a temperature of 175 C to 195 C.

3 .The compaction mould assembly and rammer are cleaned and kept pre- heated to temperature of 100 C to 145 C. The bitumen is

18

heated to temperature of 121 C to 138 Co and the required quantity of first trial percentage of bitumen is added to the heated aggregate and thoroughly mixed using a mechanical mixer or by hand mixing with trowel.4. Then the mix is heated and a temperature of 150 to 160 C is maintained and then the mix is transferred into the pre-heated mould and compacted by giving seventy five blows on each side.

5. The specific gravity values of different aggregates, filler and bitumen used are determined first. The theoretical specific gravity of the mix is determined.6. Soon after the compacted bituminous mix specimens have cooled to room temperature, the weight, average thickness and diameter of the specimen are noted. The specimens are weighted in air and then in water.7. The bulk density value of the specimen if calculated from weight and volume.8. Then the specimen to be tested is kept immersed under water in a thermostatically controlled water bath maintained at 60 ±1 C for 30 to 40 minutes.9. The specimens are taken out one, placed in the marshal test and the marshal stability value and flow are noted.10. The corrected Marshall Stability value of each specimen is determined by applying the appropriate correction factor, i9f the average height of the specimen is not exactly 63.5mm.

11. Five graphs are plotted with values of bitumen content against the values of density, Marshall Stability, voids in total mix, flow value, voids filled by bitumen.12. Let the bitumen contents corresponding to maximum density be B1 corresponding to maximum stability be B2 and that corresponding to the specified voids content (at 4.0%) be B3 . Then the optimum bitumen content for mix design is given by: B0 = (B1 +B2 +B3 )/3

OBSERVATION TABLE:-

CALCULATIONRESULT The optimum binder content of the given mix is ______________

PRECAUTIONSPROBLEMS

EXPERIMENT NO-

19

AIM To determine the flash and fire point of a given bituminous material.EQUIPMENT Pensky-martens closed cup tester, thermometer, heating source,

flame exposure.

FIGURE:

THEORYPROCEDURE 1. All parts of the cup are cleaned and dried thoroughly before the

test is started.2. The material is filled in the cup up to a mark. The lid is placed to close the cup in a closed system. All accessories including thermometer of the specified range are suitably fixed.3. The bitumen sample is then heated. The test flame is lit and adjusted in such a way that the size of a bed is of 4mm diameter. The heating of sample is done at a rate of 5 to 6 C per minute. During heating the sample the stirring is done at a rate of approximately 60 revolutions per minute.4. The test flame is applied at intervals depending upon the expected flash and fire points and corresponding temperatures at which the material shows the sign of flash and fire are noted.

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OBSERVATION TABLE:-

TEST

Trials

Mean Value1 2 3

Flash Point

Fire Point

CALCULATIONRESULT The temperature at which the flame application that causes a bright flash

____________ C and temperature at which the sample catches fire ________________ C.

PRECAUTIONSPROBLEMS

EXPERIMENT NO-

21

AIM To determine the Elongation index of the given aggregate sample.

EQUIPMENT Length gauge, I.S.Sieve

FIGURE:

THEORY The particle shape of aggregates is determined by the percentages of flaky and elongated particles contained in it. For base course and

22

construction of bituminous and cement concrete types, the presence of flaky and elongated particles are considered undesirable as these cause inherent weakness with possibilities of breaking down under heavy loads. Thus, evaluation of shape of the particles, particularly with reference to flakiness and elongation is necessary.

The Elongation index of an aggregate is the percentage by weight of particles whose greatest dimension (length) is greater than nine-fifths (1.8times) their mean dimension. This test is not applicable for sizes smaller than 6.3mm.

PROCEDURE 1. The sample is sieved through IS Sieve specified in the table. A minimum of 200 aggregate pieces of each fraction is taken and weighed

2. Each fraction is the thus gauged individually for length in a length gauge. The gauge length is used should be those specified in the table for the appropriate material.

3. The pieces of aggregate from each fraction tested which could not pass through the specified gauge length with its long side are elongated particles and they are collected separately to find the total weight of aggregate retained on the length gauge from each fraction.

4. The total amount of elongated material retained by the length gauge is weighed to an accuracy of at least 0.1% of the weight of the test sample.

5. The weight of each fraction of aggregate passing and retained on specified sieves sizes are found – W1,W2,W3, --------------- And the total weight of sample determined = W1+W2+W3+ --------- = Wg.Also the weight of the material from each fraction retained specified gauge length are found = x1,x2,x3, ------------ and the total weight retained determined = x1+ x2+ x3 + ………….. =X gm.

6. The elongation index is the total weight of the material retained on the various length gauges, expressed as a percentage of the total weight of the sample gauged.

( x1 + x2 + x3+ ------- ) Elongation index = --------------------------------× 100 (W1+W2+W3+ --------)

OBSERVATION TABLE:-

23

Size of aggregates

Length Gauge

Weight of the fraction consisting of at least 200 pieces in gm

Weight of the aggregates in each fraction retained on length gauge gm

Passing through IS Sieve mm

Retained on IS Sieve mm

50 40 81

40 25 58.50

25 20 40.50

20 16 32.40

16 12.5 25.60

12.5 10 20.20

10 6.3 14.7

CALCULATIONRESULT The elongation index of a given sample of aggregate is

_____________%

PRECAUTIONSPROBLEMS

EXPERIMENT NO-

24

AIM To determine the flakiness index of a given aggregate sample.

EQUIPMENT The apparatus consist of a standard thickness gauge, IS Sieve of size 63, 50, 40, 31.5, 25, 20, 16, 12.5, 10 and 6.3 and a balance to weight the samples.

FIGURE:

25

THEORY The particle shape of aggregates is determined by the percentages of flaky and elongated particles contained in it. For base course and construction of bituminous and cement concrete types, the presence of flaky and elongated particles are considered undesirable as these cause inherent weakness with possibilities of breaking down under heavy loads. Thus, evaluation of shape of the particles, particularly with reference to flakiness and elongation is necessary.

The Flakiness index of aggregates is the percentage by weight of particles whose least dimension (thickness) is less than three- fifths (0.6times) of their mean dimension. This test is not applicable to sizes smaller than 6.3mm.

PROCEDURE 1. The sample is sieved with the sieves mentioned in the table.2. A minimum of 200 pieces of each fraction to be tested are taken and weighed (W1 gm)3. In order to separate flaky materials, each fraction is then gauged for thickness on thickness gauge, or in bulk on sieve having elongated slots as specified in the table.4. Then the amount of flaky materials passing the gauge is weighed to an accuracy of at least 0.1% of test sample.5. Let the weight of the flaky materials passing the gauge be w1 gm. Similarly the weights of the fractions passing and retained on the specified sieves be W1, W2, W3, etc, are weighed and the total weight W1+ W2+ W3+ ……… = Wg is found. Also the weight of the material passing each of the specified thickness gauge are found = W1, W2, W3, --------- And the total weight of the material passing the different thickness gauges = w1+w2+w3+ --------------- = wg is found.

6.Then the flakiness index is the total weight of the flaky material passing the various thickness gauges expressed as a percentage of the total weight of the sample gauged (w1+w2+w3+ ------------------) Flakiness Index = ------------------------------------------×100 ( W1+W2+W3+ --------------)

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OBSERVATION TABLE:-

Size of aggregates

Thickness (0.6 times the

mean sieve) mm

Weight of the fraction consisting of at least 200 pieces in gm

Weight of the aggregates in each fraction passing thickness gauge gm

Passing through IS Sieve mm

Retained on IS Sieve mm

63 50 33.90 W1 w1

50 40 27.00 W2 w2

40 25 19.50 W3 w3

31.5 25 16.50 W4 w4

25 20 13.50 W5 w5

20 16 10.80 W6 w6

16 12.5 8.55 W7 w7

12.5 10 6.75 W8 w8

10 6.3 4.89 W9 w9

CALCULATIONRESULT The flakiness index of the given sample of aggregates is

___________%.

PRECAUTIONSPROBLEMS

27

EXPERIMENT NO-

AIM To determine the softening point of bitumen.

EQUIPMENT Ring and Ball apparatus, Water bath with stirrer, Thermometer, Glycerin, etc. Steel balls each of 9.5mm and weight of 2.5±0.08gm.

FIGURE:

THEORYPROCEDURE

28

1. Heat the material to a temperature between 75 ± 100 C above its softening point, stir until, it is completely fluid and free from air bubbles and water. If necessary filter it through IS sieve 30. Place the rings, previously heated to a temperature approximating to that of the molten material. On a metal plate which has been coated with a mixture of equal parts of glycerin and dextrin. After cooling for 30 minutes in air, level the material in the ring by removing the excess with a warmed, sharp knife.

2. Assemble the apparatus with the rings, thermometer and ball guides in position.

3. Fill the bath with distilled water to a height of 50mm above the upper surface of the rings. The starting temperature should be 50C.

4. Apply heat to the bath and stir the liquid so that the temperature rises at a uniform rate of 5±0.5 C per minute.

5. Note down the temperature when any of the steel ball with bituminous coating touches the bottom plate.

OBSERVATION TABLE:-

1 2

Temperature when ball touches the bottom, 0C

Average

Softening point of bitumen

CALCULATION29

RESULT The Softening value of given bitumen is ________________PRECAUTIONSPROBLEMS

EXPERIMENT NO-

AIM To measure the ductility of a given sample of bitumen.

EQUIPMENT Briquette mould, (length ± 75mm, distance between clips ± 30mm, width at mouth of clips ± 20mm, cross section at minimum width ± 10mm x 10mm), Ductility machine with water bath and a pulling device at a Precaliberated rate, a putty knife, thermometer..

FIGURE:

30

THEORYPROCEDURE

1. Melt the bituminous test material completely at a temperature of 75 C to 100 C above the approximate softening point until it becomes thoroughly fluid.2. Strain the fluid through IS sieve 30.3. After stirring the fluid, pour it in the mould assembly and place it on a brass plate.4.In order to prevent the material under test from sticking, coat the surface of the plate and interior surface of the sides of the mould with mercury or by a mixture of equal parts of glycerin and dextrin5. After about 30 ± 40 minutes, keep the plate assembly along with the sample in a water bath. Maintain the temperature of the water bath at 27 C for half an hour.

6. Remove the sample and mould assembly from the water bath and trim the specimen by leveling the surface using a hot knife.7. Replace the mould assembly in water bath maintained at 27 C for 80 to 90 minutes.8. Remove the sides of the moulds.9. Hook the clips carefully on the machine without causing any initial strain.10. Adjust the pointer to read zero.11. Start the machine and pull two clips horizontally at a speed of 50mm per minute.12. Note the distance at which the bitumen thread of specimen breaks.

31

13. Record the observations in the proforma and compute the ductility value report the mean of two observations, rounded to nearest whole number as the ‘Ductility Value’.

OBSERVATION TABLE:

I. Bitumen Grade =

II. Pouring Temperature =

III. Test Temperature =

IV. Periods of cooling, minutes =

(a) In air =

(b) In water bath before trimming =

(c) In water bath after trimming =

1 2 3

Initial reading

Final reading

Ductility = b-a (cm)

Ductility value

CALCULATIONRESULT The Ductility value of given bitumen is ________________PRECAUTIONSPROBLEMS

32

EXPERIMENT NO-

AIM To determine the viscosity of bituminous binder.

EQUIPMENT A orifice viscometer (one of 4.0mm diameter used to test cut back grades 0and 1 and 10mm orifice to test all other grades), water bath, stirrer andthermometer.

FIGURE:

THEORYPROCEDURE 1. Adjust the tar viscometer so that the top of the tar cup is leveled.

Select the test temperature. Heat the water in water bath to the temperature specified for the test and maintains it within ±0.1 C of the specified temperature throughout the duration of test. Rotate the stirrer gently at frequent intervals or perfectly continuously2. Clean the tar cup orifice of the viscometer with a suitable solvent and dry thoroughly.3. Warm and stir the material under examination to 20 C above the temperature specified for test and cool, while continuing the stirring.4. When the temperature falls slightly above the specified

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temperature, pour the tar into the cup until the leveling peg on the valve rod is just immersed when the latter is vertical.5. Pour into the graduated receiver 20ml of mineral oil, or one percent by weight solution of soft soap, and place it under the orifice of the tar cup.

6. Place the other thermometer in the tar and stir until the temperature is within ±0.1 C of the specified temperature. When this temperature has been reached, suspend the thermometer coaxially with the cup and with its bulb approximately at the geometric center of the tar.7. Allow the assembled apparatus to stand for five minutes during which period the thermometer reading should remain within 0.05 C of the specified temperature. Remove the thermometer and quickly remove any excess of tar so that the final level is on the central line of the leveling peg when the valve is in vertical position.8. Lift the valve and suspend it on valve support9. Start the stop watch when the reading in the cylinder is 25ml and stop it when it is 75ml. note the time in seconds.10. Report the viscosity as the time taken in seconds by 50ml of tar to flow out at the temperature specified for the test.

OBERVATION TABLE:

TEST 1 TEST 2Test Temperature

Time taken to flow 50cc of the binderViscosity

CALCULATIONRESULT The Viscosity of given bitumen is ________________PRECAUTIONSPROBLEMS

EXPERIMENT NO-

AIM 2. Determination of abrasion value by Deval’s Abrasion Machine.34

.

EQUIPMENT Deval Machine, Standard sieve, test material.

FIGURE:

THEORY Deval’s abrasion test was devised to test rock fragments. Later this test has been standardized by ASTM for finding the rate of wear of stone aggregates by crushing them to tumble one over other in a rattler in presence of abrasive charge. Deval abrasion test has also been standardized by ISI as a test for abrasion of coarse aggregates. In this test also both the abrasion and impact take place due to the steel balls used as abrasive charge.

PROCEDURE The test sample consists of dry coarse aggregates made of different percentage of the various sizes conforming to any one of the grading given in table

OBERVATION TABLE:

TEST 1 TEST 2

CALCULATIONRESULTPRECAUTIONSPROBLEMS

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