DUCTILITY TESTIS: 1208 – 1978

A test on Bitumen

HIGHWAY ENGINEERING PRACTICAL

PPT Prepared by;

Nado RinchenDhendup TashiPemba TsheringRigesh LamaRohit Adhikari

Objective:

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

2. To determine the suitability of bitumen for its use in road construction.

Apparatus:

1. Briquette mould

2. Water bath

3. Testing machine

4. Thermometer

Figure: Mould for ductility Test

Procedure:

1. The bitumen sample is melted to a temperature of 75 to 100 C above the approximate softening point until it’s fluid.

2. It is strained through IS sieve 30, poured in the mould assembly and placed on a brass plate, after a solution of glycerin and dextrin is applied at all surfaces of the mould exposed to bitumen.

3. 30-40 minutes after the sample is poured into the mould, the sample and mould assembly are removed from water bath and excess bitumen material is cut off by leveling the surface using hot knife.

4. After trimming the specimen, the mould assembly containing sample is replaced in water bath maintained at 27 C for 85-95 minutes.

5. The sides of the mould are now removed and the clips are carefully hooked on the machine without causing any initial strain.

Procedure Contd…

6. Two or more specimens may be prepared in the moulds and clipped to the machine so as to conduct these test simultaneously.

7. The pointer is to read zero.

8. The machine is started and the two clips are thus pulled apart horizontally.

9. While the test is in operation, it is checked whether the sample is immersed in water at a depth of at least 10mm.

10. The distance at which the bitumen thread of each specimen breaks, is recorded (in cm) to report as ductility value.

Precaution

1. The plate assembly upon which the mould is placed shall be perfectly flat and level so that the bottom surface of the mould touches it throughout.

2. In filling the mould, care should be taken not to disarrange the parts and thus distort the briquette and to see that no air pocket shall be within the mould sample.

3. Use glycerin/grease for easily removal of bitumen from the container.

4. Equipment should be cleaned thoroughly before testing & after testing.

Observation:

1. Bitumen grade =

2. Pouring temperature (in C) =

3. Test temperature (in C) =

4. Periods of cooling (in minutes)

i.In air =

ii.In water bath before trimming =

iii.In water bath after trimming =

Observation Table

Reading Briquette No.

1 2 3

Initial Reading      

Final Reading      

Ductility = ii-I (cm)      

Limits:

• For bitumen construction – minimum ductility of 50 cm.

• The minimum ductility values specified by Indian Standards Institution for various grades of bitumen available in India are given below:

Source of paving bitumen and penetration

grade

Minimum ductility value (cm)

Assam petroleum A25 5

A35 10

A45 12

A65, A90 & A200 15

Bitumen from sources other than Assam petroleum S35

50

S45, S65 & S90 75

Result:

• Ductility Value of the specimen =

SAMPLE Observation:

1. Bitumen grade=RT-4

2. Pouring temperature (in C) =75oC to 100oC

3. Test temperature (in C) =80oC

4. Periods of cooling (in minutes)

i.In air =30 mins

ii.In water bath before trimming = 30 mins

iii.In water bath after trimming = 90 mins

ANNEXURE 1

SAMPLE Observation Table

Reading Briquette No.

1 2 3

Initial Reading  0 0 0

Final Reading  >100 >100 >100

Ductility = ii-I (cm)  >100 >100 >100

SAMPLE Result:

• Ductility Value of the specimen = Greater than 100.