APEL Lab Manual

Prepared by:

Dr. Krishna Prapoorna Biligiri Senior Research Scientist

Patil K. S., Suraj M. S., Sumit Jain

Postgraduate Research Interns

VTI ADVANCED PAVEMENT ENGINEERING

LABORATORY MANUAL

Center for infrastructure, Sustainable Transportation and Urban Planning

Indian Institute of Science, Bangalore, Karnataka 560012, INDIA

CiSTUP, IISc Advanced Pavement Engineering Laboratory

2

TABLE OF CONTENTS

Page

1. SIEVE ANALYSIS..............................................................................................................6

2. DENSITY DETERMINATION BY PYCNOMETER ..........................................................9

3. SPECIFIC GRAVITY AND WATER ABSORPTION TEST ............................................ 11

4. FLAKINESS INDEX TEST ............................................................................................... 14

5. ELONGATION INDEX TEST .......................................................................................... 16

6. LOS ANGELES ABRASION TEST .................................................................................. 18

7. SPECIFIC GRAVITY OF BITUMEN ............................................................................... 21

8. PENETRATION TEST ...................................................................................................... 23

9. DUCTILITY TEST ............................................................................................................ 25

10. SOFTENING POINT TEST ........................................................................................... 28

11. FLASH & FIRE POINT TEST ....................................................................................... 30

12. DETERMINATION OF BINDER CONTENT FOR ASPHALT MIX ............................ 32

13. BITUMINOUS MIX DESIGN BY MARSHALL METHOD ......................................... 35

14. SUPERPAVE GYRATORY COMPACTOR (SGC) ....................................................... 44

15. DYNAMIC CONE PENETROMETER .......................................................................... 47

16. BENKELMAN BEAM DEFLECTION MEASUREMENTS .......................................... 50


3

LIST OF TABLES

Page

Table 1.1: Grain Size Distribution ...............................................................................................8

Table 3.1: Specific Gravity and Water Absorption Calculations ................................................ 13

Table 4.1: Dimensions of Thickness and Length Gauges ........................................................... 15

Table 5.1: Dimensions of Thickness and Length Gauges ........................................................... 17

Table 6.1: Grading of test samples ............................................................................................ 20

Table 6.2: Selection of Abrasive Charge.................................................................................... 20

Table 7.1: Specific Gravity Calculation ..................................................................................... 22

Table 8.1: Penetration values of the sample ............................................................................... 24

Table 9.1: Ductility values of the sample ................................................................................... 26

Table 12.1: Binder content calculation ...................................................................................... 34

Table 13.1: Correction Factors .................................................................................................. 41

Table 13.2: Aggregate Specifications ........................................................................................ 42

Table 13.3: Specifications for Marshall Properties..................................................................... 42

Table 14.1: AASHTO R 35 Superpave Gyratory Compaction Effort ........................................ 46

Table 15.1: DCP Testing ........................................................................................................... 49

Table 16.1: Calculation of Rebound Deflection ......................................................................... 53


4

LIST OF FIGURES

Page

Figure 1.1: Balance ..................................................................................................................5

Figure 1.2: IS Sieves ..................................................................................................................6

Figure 1.4: Grain Size Distribution Semi Log Plot ....................................................................7

Figure 2.1: Pycnometer ............................................................................................................8

Figure 2.2: Balance ............................................................................................................9

Figure 4.1: Thickness Gauge ..................................................................................................... 14

Figure 5.1: Length Gauge .......................................................................................................... 16

Figure 6.2: Oven .................................................................................................................... 17

Figure 6.3: Los Angeles Machine .............................................................................................. 18

Figure 7.1: Specific Gravity Bottle ............................................................................................ 21

Figure 8.1: Standard Penetrometer ......................................................................................... 22

Figure 8.2:PenetrometerNeedle ......................................................................................... 23

Figure 9.1: Ductility Testing Machine .................................................................................... 24

Figure 9.2: Standard Briquette Mould .................................................................................... 25

Figure 10.1: Ring and Ball Apparatus .................................................................................... 27

Figure 10.2: Thermometer .................................................................................... 28

Figure 11.1:Cleveland apparatus ............................................................................................... 30

Figure 12.1: Binder Centrifuge Extractor ............................................................................... 31

Figure 12.2: Precision Balance ............................................................................... 32

Figure 13.2: Sample Extractor ............................................................................................... 35

Figure 13.3: Loading Machine ............................................................................................... 36


5

Figure 13.4: Oven .................................................................................................................. 35

Figure 13.5: Compaction Pedestal and Hammer ........................................................................ 36

Figure 15.1: Dynamic Cone Penetrometer ................................................................................. 47

Figure 16.1: Benkelman Beam .................................................................................................. 50


6

1. SIEVE ANALYSIS (IS: 2720 (Part 4) 1985, ASTM D75 92, 1992)

OBJECTIVE

To determine the gradation or distribution of aggregate particle sizes within a given sample

APPARATUS

Balance: sensitive to 0.1 percent of the weight of sample to be weighed.

Sieves: 20 cm diameter and 5 cm height; provided with screens, top lid and bottom pan.

Rubber Pestle and Mortar

Mechanical Rotary Sieve Shaker

Figure 1.1: Balance Figure 1.2: IS Sieves

Figure 1.3: Mechanical Sieve Shaker

Source: www.tradeindia.com


7

PROCEDURE

1. Spread the given sample on a container and weigh the given sample.

2. Transfer the weighed sample to the top of the sieves. Cover the top sieve with the lid and

sieve on the rotary shaker for 10 minutes.

3. Collect the sample retained on each sieve carefully and weigh each sieve separately by

transferring to pre-weighed container.

4. Plot the semi-log graph of percent passing versus sieve size.

5. Determine Nominal Maximum Aggregate Size (NMAS) and maximum size of the

aggregates. The aggregate size distributions are classified as gap/skip graded, uniform

graded, well/dense graded, and open graded.

RESULTS

Maximum density gradation by Fuller.

P=100*(d/D)n

Where: P is the percentage of aggregates passing the sieve size d; D is the maximum aggregate

size in the gradation; and n is an exponent.

The range of n is 0.45 to 0.50 depending upon the shape of the aggregate. For maximum particle

density (spherical shape), n is 0.50. For pavement works, n is taken as 0.45 (air void

consideration).

Figure 1.4: Grain Size Distribution Semi Log Plot


8

D10 = D30 = D60 =

Coefficient of Uniformity, Cu = D60 / D10 =

Coefficient of Curvature, Cc = (D30)2 / (D10x D60) =

NMAS: is one sieve size larger than the first size to retain more than 10 percent by weight of the

aggregates=

Maximum size of aggregate: is the smallest sieve through which 100 percent of the particles will

pass.

Table 1.1: Grain Size Distribution

Sieve size,

mm

Weight

retained, g

Cumulative weight

retained, g

Cumulative percentage

weight retained

Percent

passing

19.0

9.5

4.75

2.36

1.18

0.6

0.3

0.15

0.075

Pan

Total

DISCUSSION


9

2. DENSITY DETERMINATION BY PYCNOMETER (IS 2386 (Part 3) 1963)

OBJECTIVE

To determine the density of the given aggregate sample using pycnometer

APPARATUS

Pycnometer

Balance

Figure 2.1: Pycnometer Figure 2.2: Balance

PROCEDURE

1) Determine the weight of the empty and dry pycnometer, designated as m0.

2) Fill about 1/3rd of pycnometer volume with aggregate and measure the weight m1.

3) Add water such that pycnometer as well as capillary holes are filled with water and

measure total weight m2.

4) Empty the pycnometer and fill it with distilled water only and measure the weight m3.

5) Calculate the weight of water, mH2O=m3 m0.

6) Calculate the weight of aggregate, mS = m1 - m0 and weight of added water

mH2O = m2 - m1.

7) Calculate aggregate volume VS and its density s as


10

Vs = V - VH2O= (mH2O - mH2O) / H2O

s= ms/ Vs

Where: V : Volume of water that fills the empty pyconometer

VH2O :Volume of water weighing mH2O.

RESULTS

m0 m1 m2 m3 mH2O mS mH2O VS s

Density of the given aggregate sample = s

=

DISCUSSION


11

3. SPECIFIC GRAVITY AND WATER ABSORPTION TEST (IS 2386 Part 3, 1963)

OBJECTIVE

To determine the specific gravity and water absorption of aggregates by using aggregate density

basket

APPARATUS

Aggregate density basket

Oven

A container for filling water and suspending the basket

Balance suitable for weighing of the sample container when suspended in water

A shallow tray and two dry absorbent clothes

Figure 3.1: Aggregate density basket Figure 3.2: Oven

Source: www.Indiamart.com


12

PROCEDURE

1) Wash and drain 2 kg of the aggregate sample thoroughly to remove fines.

2) Place it in the aggregate density basket and immerse the basket in distilled water at a

temperature between 22 and 32 0C with a cover of at least 50 mm of water above the top

of the basket.

3) Remove the entrapped air by lifting the basket containing it 25 mm above the base of the

tank and allowing it to drop 25 times at a rate of about one drop per second.

4) Keep the basket and aggregate completely immersed in water for a period of 24 + 0.5

hours afterwards.

5) Weigh the basket and the sample (W1 g) while suspended in water at a temperature of 22

to 32 0C.

6) Remove the basket from water and allow it to drain for a few minutes.

7) Transfer the aggregates to one of the dry absorbent clothes.

8) Immerse the empty basket in water, jolt it for 25 times and weigh it in water (W2 g).

9) Surface dry the aggregates placed on the absorbent clothes completely using both the

clothes. 10 to 60 minutes drying may be needed.

Note: Do not expose the surface dried aggregates to direct sunlight or any other source of heat.

10) Weigh the surface dried aggregates (W3 g).

11) Place the aggregates in a shallow tray and keep in an oven maintained at a temperature of

110 0C for 24 hours.

12) Weigh the oven dried aggregates (W4 g).

Note: Carry out the test at least twice but not concurrently.


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RESULTS

Table 3.1: Specific Gravity and Water Absorption Calculations

No. W1

(g)

W2

(g)

W3

(g)

W4

(g)

Weight of

saturated

aggregate in

water, Ws=

W1-W2 (g)

Sp.

Gravity

= W4 /

(W3-Ws)

Apparent

Sp.

Gravity =

W4 / (W4-

Ws)

Water

Absorption(%)

= (W3-

W4)/W4X100

1

2

Specific Gravity of the aggregates =

Apparent Specific Gravity of the aggregates =

Water Absorption (%) =

DISCUSSION


14

4. FLAKINESS INDEX TEST (IS 2386, 1963; BS 812, Part 3, 1975)

OBJECTIVE

To determine the Flakiness Index of the given aggregate sample

APPARATUS

A metal thickness gauge.

IS test sieves.

A balance accurate to 0.5% of mass of the test

sample.

Figure 4.1: Thickness Gauge

PROCEDURE

1) Carry out the sieve analysis using the sieves given in the Table 4.1.

2) Do not use the aggregate retained on 63mm and passing 6.3mm for the tests to be carried

out.

3) Then weigh each of the individual size fractions retained on the sieves, other than the 63

mm IS test sieve, and store them in separate trays. This weight is taken as M1.

4) Calculate the individual percentage retained on each of the various sieves and discard any

fraction of which the mass is 5% or less of mass M1. Record the remaining mass as M2.

5) Now select the thickness gauge appropriate to the size fraction as mentioned in the Table

4.1 and gauge each particle separately by hand.

6) Combine and weigh all the particles passing these gauges and note this weight as M3.


15

Table 4.1: Dimensions of Thickness and Length Gauges

IS test Sieve size (mm)

Thickness Gauge

(mm)

Mass M1(g)

100% Passing

100% Retained

Thickness Gauge

63 50 33.9 +0.3

50 37.5 26.3+0.3

37.5 28 19.7+0.3

28 20 14.4+0.15

20 14 10.2+0.15

14 10 7.2+0.1

10 6.3 4.9+0.1

RESULTS

Sum of individual masses in trays = M1 (g) =

Sum of individual masses in trays as described above = M2 (g) =

Combined mass of aggregates passing gauges = M3 (g) =

Flakiness Index of the given Aggregate sample (%) = (M3/M2)*100

=

Note: If no fraction as a mass 5% or less than mass M1, then M1=M2(g)

DISCUSSION


16

5. ELONGATION INDEX TEST

OBJECTIVE

To determine the Elongation Index of the given aggregate sample

APPARATUS

A metal length gauge.

IS test sieves as mentioned in Table 5.1

A balance accurate to 0.5% of mass of the test sample.

Figure 5.1: Length Gauge

PROCEDURE

1. Carry out the sieve analysis using the sieves given in Table 5.1.

2. Discard all aggregate retained on the 50.0 mm IS test sieve and all aggregate passing the 6.3

mm IS test sieves.

3. Weigh and store each of the individual size fractions retained on the other sieves in separate

trays with their size marked on the tray.

4. Sum the individual masses in the trays as M1 and calculate the individual percentages retained

on each of the various sieves. Discard any fraction whose mass is 5% or less of mass M1, and

record the remaining mass as M2.

5. Select the length (elongation) gauge appropriate to the size fraction as mentioned in the Table

5.1 and gauge each particle separately by hand.

Note: Elongated particles are those whose greatest dimension prevents them from passing

through the gauge

6. Now combine and sum all these elongated samples and record their weight as M3.


17

Table 5.1: Dimensions of Thickness and Length Gauges

BS test Sieve size (mm)

Length Gauge

(mm)

Mass M1(g)

100% Passing

100% Retained

Length Gauge

63 50 -

50 37.5 78.7+0.3

37.5 28 59.0+0.3

28 20 43.2+0.3

20 14 30.6+0.3

14 10 21.6+0.2

10 6.3 14.7+0.2

RESULTS

Sum of individual masses in trays = M1 (g) =

Sum of individual masses in trays as described above = M2 (g) =

Combined mass of Elongated Samples = M3 (g) =

Elongation Index of the given Aggregate Sample (%) = (M2/M3)*100 =

Note: If no fraction as a mass 5% or less than mass M1 then, M1=M2(g)

DISCUSSION


18

6. LOS ANGELES ABRASION TEST (IS 2386 (part iv) - 1963, AASHTO T 96, ASTM C 131)

OBJECTIVE

To determine the Los Angeles abrasion value for given aggregate sample

APPARATUS

Los Angeles Abrasion Testing Machine

Abrasive Charge Cast iron or steel balls

Test sieve 1.70 mm IS sieve

Balance of capacity 10 kg

Oven

Tray Figure 6.1: Balance

Figure 6.2: Oven Figure 6.3: Los Angeles Machine


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PROCEDURE

The test sample consists of clean aggregates dried in oven at 105 110C. The sample should

conform to any of the grading shown in Table 6.1.

1) Select the grading to be used in the test such that it conforms to the grading being used in

the construction, to the maximum extent possible.

2) Take 5 kg of sample for grading A, B, C & D and 10 kg for grading E, F & G.

3) Choose the abrasive charge as per Table 6.2 depending on the grading of aggregates.

4) Place the aggregates and abrasive charge in the cylinder and fix the cover.

5) Rotate the machine at a speed of 30 33 revolutions per minute. The number of

revolutions is 500 for grading A, B, C & D and 1000 for grading E, F & G. The machine

should be balanced and driven such that there is uniform peripheral speed.

6) Stop the machine after desired number of revolutions and discharge material to a tray.

7) Sieve the entire material on tray through 1.70 mm IS sieve.

8) Weigh the material retained on 1.70 mm IS sieve correct to one gram.

RESULTS

Original weight of aggregate sample = W1 g

Weight of aggregate sample retained = W2 g

Weight passing 1.7mm IS sieve = W1 - W2 g

Los Angeles Abrasion Value = (W1 - W2) / W1 X 100

=

DISCUSSION


20

Table 6.1: Grading of test samples

Sieve size Weight of test sample (g)

Passing

(mm)

Retained

on (mm) A B C D E F G

80 63 2500*

63 50 2500*

50 40 5000* 5000*

40 25 1250 5000* 5000*

25 20 1250 5000*

20 12.5 1250 2500

12.5 10 1250 2500

10 6.3 2500

6.3 4.75 2500

4.75 2.36 5000

*Tolerance of 12 percent permitted.

Table 6.2: Selection of Abrasive Charge

Grading No. of Steel balls Weight of charge (g)

A 12 5000 25

B 11 4584 25

C 8 3330 20

D 6 2500 15

E 12 5000 25

F 12 5000 25

G 12 5000 25


21

7. SPECIFIC GRAVITY OF BITUMEN (IS: 1202 1978; AASHTO T209-11, 2011; ASTM D 2041-11, 2011)

OBJECTIVE

To determine the specific gravity of a given bitumen sample

APPARATUS

Specific gravity bottles of 50ml capacity

Water bath

Bath thermometer Range 0 to 44oC, Graduation 0.2oC

Figure 7.1: Specific Gravity Bottle

PROCEDURE

1) At first, clean, dry and weigh the specific gravity bottle along with the stopper and this

weight is taken as Weight A.

2) Now fill the specific gravity bottle with freshly boiled distilled water and slot in the

stopper firmly.

3) Keep this bottle is kept in the water bath having a temperature of 27.0 + 1oC for not less

than half an hour and its weight is taken as Weight B.

4) Weigh the specific gravity bottle about half-filled with bitumen and weigh it. This is

noted as Weight C.

5) Now pour the distilled water to remaining half portion of the above bottle filled with

bitumen and note the weight as Weight D.

6) Repeat the above experiment one more time.


22

RESULTS

Table 7.1: Specific Gravity Calculation

Grade of Bitumen:

A (g) B (g) C (g) D (g) Specific Gravity =(C-A )/[(B-A)-(D-C)]

Test 1

Test 2

Specific gravity of the given bitumen Sample= Average specific Gravity of both the test results

=

DISCUSSION


23

8. PENETRATION TEST (IS: 1203: 1978, BS 1426: 2000, ASTM D5 97, 1997)

OBJECTIVE

To determine the penetration of a given sample of bitumen

APPARATUS

Standard Penetrometer

Water bath

Bath thermometer Range 0 to 44oC, Graduation 0.2oC

Figure 8.1: Standard Penetrometer Figure 8.2:PenetrometerNeedle

PROCEDURE

1) Soften the bitumen above the softening point by heating it between 75 and 100 oC.

2) Remove air bubbles and water by stirring the softened sample thoroughly.

3) Make sure bitumen should be just sufficient to fill the container to a depth of at least

15mm in excess of the expected penetration.

4) Cool the bitumen sample at an atmospheric temperature of 15 to 30 oC for 1.5 hours.

5) After that place it in a transfer dish in the water bath at 25 + 0.1 oC for 1.5 hours.

6) Keep the container on the stand of the penetration apparatus and adjust the needle such

that it makes contact with the surface of the sample.


24

7) Adjust the dial gauge reading to zero.

8) Release the needle for exactly 5 seconds and then record the dial gauge reading expressed

in tenths of a millimeter.

9) Repeat the above procedure three times.

RESULTS

Table 8.1: Penetration values of the sample

Grade of bitumen:

No. Dial gauge reading Penetration value (0.1 mm)

1

2

3

Final Penetration Value (mm) = Average of the three readings

=

DISCUSSION


25

9. DUCTILITY TEST (IS: 1208 1978;ASTM D113-07, 2007; AASHTO T51-08, 2008)

OBJECTIVE

To determine the ductility of a given sample of bitumen

APPARATUS

Standard briquette mould

Water bath

Testing machine

Thermometer Range 0 to 44oC, Graduation 0.2oC

Figure 9.1: Ductility Testing Machine Figure 9.2: Standard Briquette Mould

PROCEDURE

1) Heat the bituminous material to be tested to a temperature of 75 to 100oC above the

approximate softening point until it becomes thoroughly fluid.

2) Assemble the mould on a brass plate (Figure 9.2).

3) Thoroughly coat the surface of the plate and the interior surfaces of the sides of the

mould with a mixture of equal parts of glycerin and dextrin to prevent the material under

test from sticking to the surface.


26

4) Pour the material in a thin stream back and forth from end to end of the mould until it is

more than level full.

5) Leave it to cool at room temperature for 30 to 40 minutes and then place it in a water bath

maintained at the specified temperature for 30 minutes.

6) Now, remove the excess bitumen by means of a hot, straight-edged putty knife or spatula

to make the mould just level full.

7) Place the brass plate and mould with briquette specimen in the water bath at the specified

temperature for about 85 to 95 minutes.

8) Remove the briquette from the plate; detach the side pieces and the briquette

immediately.

9) Attach the rings at each end of the two clips to the pins or hooks in the testing machine

and pull the two clips apart horizontally at a uniform speed, as specified, until the

briquette ruptures.

10) Measure the distance in cm at which the rupture occurs.

Note: While the test is being done, make sure that the water in the tank of the testing machine

covers the specimen both above and below by at least 25mm and the temperature is maintained

continuously within 0.5oC of the specified temperature.

RESULTS

Table 9.1: Ductility values of the sample

Grade of Bitumen -

No. Ductility (cm)

1

2

3


27

Note: A normal test is one in which the material between the two clips pulls out to a point or to a

thread and rupture occurs where the cross-sectional area is minimum. Report the average of

three normal tests as the ductility of the sample, provided the three determinations be within

0.5 percent of their mean value.

If the values of the three determinations do not lie within 0.5 percent of their mean, but the two

higher values are within 0.5 percent of their mean, then record the mean of the two higher

values as the test result.

Ductility (cm) = Average of the three readings

=

DISCUSSION


28

10. SOFTENING POINT TEST (IS: 1205, BS2000-58, ASTM D36-95, 1995, AASHTOT53-06, 2006)

OBJECTIVE

To determine the softening point of a given bitumen sample

APPARATUS

Ring and ball apparatus

Thermometer -Low Range : -2 to 80oC, Graduation 0.2oC

-High Range: 30 to 200oC, Graduation 0.5

oC

Figure 10.1: Ring and Ball Apparatus Figure 10.2: Thermometer

PROCEDURE

Preparation of sample

1) Fill the ring with the sample. Cut off the excess sample by a knife.

2) Heat the material between 75 and 100oC. Remove air bubbles and water by stirring it and

then, filter it through IS Sieve 30, if necessary.

3) Heat the rings and apply glycerin.

4) Now fill the material in rings and cool it for 30 minutes.

5) Use a warmed, sharp knife to remove the excess material.


29

For Materials of softening point below 80oC

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

7) Fill the beaker with boiled distilled water at a temperature 5.0 0.5 oC per minute.

8) With the help of a stirrer, stir the liquid and apply heat to the beaker at a temperature of

5.0 0.5 oC per minute.

9) Apply heat until the material softens and allow the ball to pass through the ring.

10) Record the temperature at which the ball touches the bottom, which is nothing but the

softening point of that material.

For Materials of softening point above 80 oC

The procedure is the same as described above. The only difference is that instead of water,

glycerin is used and the starting temperature of the test is 35 oC.

RESULTS

Softening point (oC) = the temperature at which the ball touches the bottom

=

DISCUSSION


30

11. FLASH & FIRE POINT TEST (IS: 1205, BS2000-58, 1958, ASTM D36-95, 1995, AASHTO T53-06, 2006)

OBJECTIVE

To determine the Flash & Fire point test of a given bitumen sample

APPARATUS

Cleaveland apparatus

Thermometer-Low Range: -7 to 110 oC, Graduation 0.5 oC

-High Range: 90 to 370 oC, Graduation 2

oC

Figure 11.1:Cleveland apparatus

PROCEDURE

Note: Bitumen is just sufficient to fill the cup up to the mark given on it.

Flash Point

1) Heat the bitumen between 75 and 100 oC & remove the air bubbles and water by stirring

the sample.

2) Fill the cup with the bitumen to be tested up to the mark & place it on the bath. Fix the

open clip; insert the thermometer of high or low range as per requirement and also the

stirrer, to stir the sample.


31

3) Light the test flame and supply heat at such a rate that the temperature increase, recorded

using a thermometer is neither less than 5oC nor more than 6

oC per minute.

4) Note the temperature at which first flash appears when test flame is bought close to the

surface of the material. This temperature is noted as Flash point temperature.

Note: Do not get confused with the bluish halo that sometimes surrounds the test flame with the

true flash.

Fire Point

5) After flash point is obtained, heating should be continued at such a rate that the increase

in temperature recorded by the thermometer is neither less than 5oC nor more than 6

oC

per minute.

6) Now light a test flame and adjust it so that it is of the size of a bead 4mm in diameter.

7) Finally note that thermometer at which the application of test flame causes the material to

ignite and burn for at least 5 seconds. This temperature is noted as Fire point temperature.

RESULTS

Flash point temperature (oC) =

Fire point temperature (oC) =

DISCUSSION


32

12. DETERMINATION OF BINDER CONTENT FOR ASPHALT MIX

(IRC: SP 11 1988 (Appendix - 5), ASTM D 2172-95, 1995, AASHTO T 164-08, 2008)

OBJECTIVE

To determine the binder content in the asphalt mix by cold solvent extraction

APPARTUS

Binder Centrifuge Extractor

Balance of capacity 500 g and sensitivity 0.01 g

Thermostatically controlled oven with capacity up to 250oC

Beaker for collecting extracted material

Figure 12.1: Binder Centrifuge Extractor Figure 12.2: Precision Balance

PROCEDURE

1) Take a known weight (W1) of representative sample and place it in the bowl of extraction

apparatus.

2) Add benzene to the sample until it is completely submerged.


33

3) Take a dry filter paper with weight (F1) and place it over the bowl of the extraction

apparatus containing the sample.

4) Clamp the cover of the bowl tightly.

5) Place a beaker under the drainpipe to collect the extract

6) Allow sufficient time (not more than an hour) for the solvent to disintegrate the sample

before running the centrifuge.

7) Run the centrifuge slowly and then gradually increase the speed to a maximum of 3600

rpm.

8) Maintain the same speed till the solvent ceases to flow from the drainpipe.

9) Run the centrifuge until the bitumen and benzene are drained out completely.

10) Stop the machine, remove the cover and add 200ml of benzene to the material in the

extraction bowl and the extraction is done in the same process as described above.

11) Repeat the same process not less than three times till the extraction is clear and not darker

than a light straw color.

12) Collect the material from the bowl of the extraction machine along with the filter paper

and dry it to constant weight in the oven at a temperature of 105 to 1100C and cool to

room temperature.

13) Weigh the material (W2) and the filter paper (F2) separately to an accuracy of 0.01 g.

RESULTS

W1 (W2 + W3)

Percentage of binder in the total mix = ---------------------- x 100

W1

W1 = Weight of sample taken

W2 = Weight of sample after extraction

W3 = Increased weight of filter paper (F2 F1)


34

Table 12.1: Binder content calculation

Sample No. W1 (g) W2 (g) F1 (g) F2(g) W3 (g) Binder Content (%)

1

2

3

Final Binder Content (%) = Average of three samples

=

DISCUSSION


35

13. BITUMINOUS MIX DESIGN BY MARSHALL METHOD (ASTM D1559, 1993)

OBJECTIVE

To determine optimum binder content of given bituminous mix by Marshall Method of Mix

Design

APPARATUS

Mould Assembly: Cylindrical moulds of 10 cm diameter and 7.5 cm height consisting of

a base plate and collar extension.

Sample Extractor

Compaction Pedestal and Hammer: Used to compact a specimen by 4.54 kg weight with

45.7 cm height of fall.

Breaking Head: Used to test the specimen by applying a load on its periphery

perpendicular to its axis in a loading machine of 5 tones capacity at a rate of 5 cm/min.

Loading Machine: Measures the maximum load supported by the test specimen at a

loading rate of 50.8 mm/min at 60 0C.

Flow Meter: An attached dial gauge measuring the flow value as a result of the loading in

0.25 mm increments.

Thermometers

Water Bath

Oven

Figure 13.1: Mould Assembly


36

Figure 13.2: Sample Extractor Figure 13.3: Loading Machine

Figure 13.4: Oven Figure 13.5: Compaction Pedestal and Hammer

PROCEDURE

In the Marshall test method of mix design three compacted samples are prepared for each binder

content. At least four binder contents are to be tested to get the optimum binder content.

1) Prepare a mix of coarse aggregates, fine aggregates and mineral filler material in such a

proportion that final mix after blending has the graduation within the specified range

(Table 13.2).


37

2) Take approximately 1200 grams of aggregates and filler, and heat them to a temperature

of 175 to 195 0C.

3) Clean the compaction mould assembly and rammer, and heat to a temperature of 100 to

145 0C. Heat the bitumen to a temperature of 121 to 138

0C and add the required quantity

of first trial percentage of bitumen to the heated aggregate and thoroughly mix using a

mechanical mixer or by hand mixing with trowel.

4) Then heat the mix at a temperature of 150to 160 0C.

5) Transfer the mix into the pre-heated mould and compact it by giving seventy five blows

on each side.

6) Soon after the compacted bituminous mix specimens have cooled to room temperature,

take the sample out of the mould using the sample extractor and measure the weight,

average thickness and diameter of the specimen. Weigh the specimens in air and then in

water.

7) Determine the theoretical specific gravity of the mix using the known specific gravity

values of different aggregates, filler and bitumen.

8) Calculate the bulk density value of the specimen from weight and volume.

9) Then immerse the specimen to be tested under water in a thermostatically controlled

water bath maintained at 60 10C for 30 to 40 minutes.

10) Take out the specimens from the water bath and place them in the Marshall loading

machine to measure the marshal stability and flow values.

11) If the average height of the specimen is not exactly 63.5mm, then correct the Marshall

Stability value of each specimen by applying the appropriate correction factor (Table 1).

12) Plot five graphs with values of bitumen content against the values of density, Marshall

Stability, voids in mineral aggregates(VMA), flow value and voids filled by

bitumen(VFB).

13) 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:

Bo= (B1+B2+B3)/3.


38

RESULTS

The optimum Bitumen Content of the given mix, Bo =

=

DISCUSSION


39

Data Sheet 1

Specification for Aggregate Selection

No. Sieve size (Passing)

Specificatio

n Range

(%) Pass

Our

Selection

%

Retained

Sample Wt.

(g)

0 25.0 mm to 19.0 mm 100

1 19.0 mm to 12.5 mm 66 95

2 12.5 mm to 9.5 mm 54 88

3 9.5 mm to 4.75 mm 37 70

4 4.75 mm to 2.36 mm 26 52

5 2.36 mm to 1.18 mm 18 40

6 1.18 mm to 600 m 13 30

7 600 m to 300 m 8 23

8 300 m to 150 m 6 16

9 150 m to 75 m 4 10

10 < 75 m (filler) Pan 0

Total wt. = 1200 g

% of Total

Aggregate

Coarse Aggregate =

Fine Aggregate =

Filler (Agg. dust) =

% Bitumen Wt. of bitumen

Specific

Gravity

Coarse Aggregate

Fine Aggregate

Filler

Bitumen


40

Data Sheet 2

Aggregate grading type :

Mixing temp. oC :

Grade of Bitumen :

No. of blows :

Compaction temperature :

% Asphalt by

Weight of

Total

Aggregate

Mix

Weight of specimen (g) Gbcm Stability Flow

In Air In Water

1 2 3 1 2 3 1 2 3 1 2 3 1 2 3


41

Data Sheet 3

Asphalt % by

weight of Total

Aggregate Mix

Gbcm Volume Gbam Gmp VMA Pav

Stability

Flow Obs. Corr.

Table 13.1: Correction Factors

Volume of

Specimen

(cm3)

Thickness

of

Specimen

(mm)

Correction

Factor

457 470 57.1 1.19

471 482 68.7 1.14

483 495 60.3 1.09

496 508 61.9 1.04

509 522 63.5 1

523 535 65.1 0.96

536 546 66.7 0.93

547 559 68.3 0.89

560 573 69.9 0.86


42

Table 13.2: Aggregate Specifications

Table 13.3: Specifications for Marshall Properties

Sieve Size

(mm)

Percent by Passing Weight

Type 1

Base course

Type 2

Binder or

leveling

course

Type 3

Wearing

course

37.5 100 25 72 100 100 19 60 - 89 82 - 100 100

12.5 46 - 76 60 - 84 66 95

9.5 40 - 67 49 - 74 54 88

4.75 30 - 54 32 - 58 37 70

2.36 22 - 43 23 - 45 26 52

1.18 15 - 36 16 - 34 18 40

0.6 10 28 12 25 13 30

0.3 6 22 8 20 8 23

0.15 4 14 5 13 6 16

0.075 2 8 4 7 4 10

Asphalt

cement (% by

weight of

total

aggregate)

3.5 - 5.0 4.0 - 6.5 4.5 - 6.5

Description

Type 1 Base course Type 2 Binder or

leveling course

Type 3 Wearing

course

Min. Max. Min. Max. Min. Max.

Marshall specimens (ASTM D

1559) No. of comp. Blows, each

end of specimen

75 75 75

Stability, kg. 350 500 600 Flow, 0.25 mm 8 16 8 16 8 16

VMA 13 14 15 Air voids, % 3 8 3 8 4 6

Aggregate voids filled with

bitumen, % 60 80 65 85 70 85

Immersion compression

specimen (AASHTO T 165)

index of retained strength, %

70 70 70


43

Figure 13.6: Typical plots for Marshall Test

Note: Refer to the textbook for examples


44

14. SUPERPAVE GYRATORY COMPACTOR (SGC) (AASHTO T 312-11, 2011)

OBJECTIVE

To prepare specimens of hot mix asphalt (HMA) using the Superpave gyratory compactor to

determine the volumetric and mechanical properties of the mixture

APPARATUS

Superpave Gyratory Compactor (SGC) meeting the requirements of AASHTO T 312

Molds meeting the requirements of AASHTO T 312

Chute, mold funnel or both (Optional)

Scale meeting the requirements of AASHTO M 231 Class G 5

Oven, thermostatically controlled, capable of maintaining set temperature within 3C

Thermometers accurate to 1C between 10 and 232 C Note 1: Non-Contact thermometers are not acceptable.

Miscellaneous pans, spoons, spatulas, hot pads, gloves, paper discs, markers, etc.

Figure 14.1: Superpave gyratory compactor (SGC)


45

PROCEDURE

1) Prepare the laboratory asphalt mixture by batching the aggregates, mixing in the proper

amount of binder, conditioning the prepared mixture approximately 4700 g to provide

enough material for a finished specimen height of 115 5 mm.

2) Turn on the power to compactor for the warm up period as recommended by the

manufacturer prior to the time the HMA is ready for compaction.

3) Check the settings of the compacter,

-Internal Angle: 1.16 0.02

-Ram Pressure: 600 18 kPa

-Number of gyrations: (From Table 14.1)

4) Preheat the mold, base plate, and funnel in an oven at 93 C for 30-60 minutes to prevent

the asphalt mix from sticking to molds during the compaction process and sticking in the

funnel during sample preparation.

5) Heat the asphalt mixture in an oven at 132 C. When the asphalt mixture reaches 132 C,

remove the heated mold and base plate from the oven and place a paper disk in the

bottom of the mold.

6) Mix the entire sample to be compacted with a heated spoon and then carefully put the

sample in a funnel. With the funnel, place all the mixture into the mold. With a heated

spoon or spatula level the mix in the mold and place a paper disk on the top.

7) Load the mold into the compactor and center the loading ram. Set the pressure, angle

setting, and gyrations per minute. Start the compactor and wait for the compaction

process to finish.

8) When completed, remove the mold assembly from the compactor. The specimens can be

removed immediately from the mold after compaction for most HMA mixes. In order to

insure the specimen does not get damaged, a cooling period of 5 to 10 minutes in front of

a fan may be necessary.

9) Remove the specimen with an extrusion jack. Remove the paper disks from the top and

bottom of the specimen.

Notes: Before testing, the gyratory compactor should be calibrated periodically for

pressure, height, angle, and rotation to make sure compactor is within specifications.


46

RESULTS

Table 14.1: AASHTO R 35 Superpave Gyratory Compaction Effort

20-Year Design Traffic, ESALs

(millions)

NDesign(Number of Design

Gyrations)

< 0.3 50

0.3 to < 3 75

3 to < 10 100

10 to < 30 100

> 30 125

Number of Design Gyrations =

DISCUSSION

.


47

15. DYNAMIC CONE PENETROMETER

OBJECTIVE

To measure the in-situ strength and thickness of soil layers underlying the bound pavement

layers

APPARATUS

Dynamic cone Penetrometer

Measuring scale

Figure 15.1: Dynamic Cone Penetrometer

PROCEDURE

1) Assemble the DCP by attaching the cone tip, connect upper and lower shafts.

2) Test the soil layer beneath a bound pavement layer by cutting a hole through the bound

pavement layer of at least 50mm in diameter.

3) Place the DCP on the test surface or insert DCP in the center of the hole and carryout

seating operation.

4) Establish a reference for reading the penetration of the shaft after each blow; do not

record penetration during seating operation.

5) Raise the hammer to its upper limit and allow it to fall freely without lifting the shaft.

Note: Be careful to not influence the drop by forcing the hammer down.

6) Record the reading and the blow count by reading the shaft to the nearest millimeter.

7) Repeat steps 5 and 6 until the cone is driven to the full depth of lower shaft, the total

penetration is less than 3mm for ten consecutive drops or the desired depth is reached.


48

Note: Do not remove the DCP by forcefully striking the hammer against the handle. This will

damage the DCP.

RESULTS

The vertical movement of DCP cone produced by one drop of hammer,

Dynamic Penetration Index, DPI (mm/blow) = (PR2 PR1)/ (DN2 DN1)

=

Where, PR Penetration reading

Log10 (CBR) = 2.48-1.057 * Log10 (DPI)

CBR =

DISCUSSION


49

Table 15.1: DCP Testing

Drop

Number

(DN)

Rod Reading

(mm)

Invert Reading

(mm)

Penetration Index

(mm/blow)

Estimated

CBR

0

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20


50

16. BENKELMAN BEAM DEFLECTION MEASUREMENTS (IS 2386 (Part IV) - 1963, BS 812, Part 3, 1975)

OBJECTIVE

To determine the rebound deflection of a pavement surface

APPARATUS

A Benkelman beam

Figure 16.1: Benkelman Beam

A truck or trailer with an rear axle load of 8170kg equally distributed on two dual tired

wheels

A tire pressure of 5.6 kg/cm2 for loading the pavement

A thermometer with a range of 0-6 C in 1 C divisions

A mandrel suitable for making a 100mm deep hole in the pavement for inserting the

thermometer

A can containing either glycerol or oil for filling the thermometer hole

PROCEDURE

Calibration of Benkelman Beam

1. Calibrate the Benkelman Beam so that to ensure that the dial gauge and beam are

working correctly. This is done as described below.

2. Place the beam and level it on a hard surface.

3. Place a metallic block of known thickness under the probe and read the dial gauge

reading.

4. If the beam is in order then the dial gauge reading would be half of that of the metallic

block otherwise the dial gauge is checked and replaced if necessary.

5. If the dial gauge is functioning correctly then the beam pivot is checked for smooth and

free movements.

6. Check the dial gauge spindle beneath the striking plate to ensure that it is tightly secured

and has not become grooved by the dial gauge stylus.


51

Deflection measurements

Deflections shall be measured as follows:

1. Select a section of a road with preferable length not less than 1 km. In each of these

sections a minimum of 10 points are marked at equal distance to measure deflections in

the outer wheel path.

Note: For highway pavements following table should be referred to select the Test points.

The interval between the points should not be more than 50m in a lane. If for roads having more

than one lane, mark the points on adjacent lanes in a staggered fashion.

Lane Width

(Meters)

Distance from lane Edge

(Meters)

< 3.5 0.6

>3.5 0.9

Divided 4 lane Highway 1.5

If the highest or lowest deflection values in a group of ten differs from the mean by more

than one-third of mean then extra deflection measurements is made at 25m on either

side of point where high or low values are observed.

2. Center the dual wheels of the truck above the selected point.

3. The probe of the Benkelman beam is inserted between the duals and placed on the

selected points.

4. Release the locking device and adjust the rear of the beam so that the plunger is in

contact with the stem of the dial gauge.

5. Set the dial gauge at approximately 1 cm and record the initial reading when rate of

deformation of the pavement is equal or less than 0.025 mm per minute.

6. After initial reading is recorded, the truck is slowly driven a distance of 270 cm and

stopped.


52

7. Now record the dial gauge reading with truck at the above mentioned position and note

that the recording is done when the rate of recovery of the pavement is equal to or less

than 0.025mm per minute.

8. Move the truck further by 9m.

9. Record the final reading when the rate of recovery of the pavement is equal to less than

0.025 mm per minute.

10. Also record the pavement temperature at least once every hour inserting thermometer in

the standard hole with the hole filled with glycerol.

Note: Check the tire pressure at an interval of 2-3 hours and adjust to the standards

RESULTS

If (Di Df) 0.025 mm

Actual deflection (XT) = 2 (Di Df)

=

If (Di - Df) > 0.025 mm,

Actual deflection (XT) = 2(Di Df) + 2.91 [2 (Df Di)]

=

1. Rebound Deflection= 2 x XT

=


53

Table 16.1: Calculation of Rebound Deflection

Chainage

(m)

Pavement

Temperature,

(0C)

Initial

Reading(D0)

(mm)

Intermediate

Reading(Di)

(mm)

Final

Reading(Df)

(mm)

Rebound

Defection, x

(mm)

2. Mean deflection = x = x / n

=


54

3. Standard deviation = = ( ( x x )2 / n-1)

=

4. Characteristic Deflection = Dc = x +

=

DISCUSSION

APEL Lab Manual

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