Class Name: Pavement design lab
Class Number: CEE533
Report Title: Ductility test
Name: Qusai Alsaadat
Date: 21/7/2020
Introduction:
Ductility test of bitumen is one of the main testes that you need to do during road
construction. We know that the ductility of a material is the ability of that material
to undergo plastic deformation (permanent deformation) before the rupturing
(breaking) of that material.
The ductility of a bituminous material is measured by the distance in cm to which it
will elongate before breaking when a standard briquette specimen of the material is
pulled apart at a specified speed and a specified temperature.
Objectives:
Determining the distance of elongation for a bitumen material before breaking at a
specific speed and specific temperature.
Apparatus:
1. Ductility testing machine (Ductilometer)
2. Ductility mold and plate
3. Water path
4. Thermometer
5. Hotplate
6. Spatula
Materials used:
Bitumen
Procedure:
1. The bituminous material tested is completely melted by heating it to a
temperature of 75 to 100-degree Celsius above the approximate softening
point until it becomes thoroughly fluid.
2. The mold is assembled on a brass plate and in order the material is prevented
under test from sticking, thoroughly coat the surface of the plate and the
interior surfaces of the sides of the mold with a mixture of equal parts of
glycerin and dextrin.
3. While filling, the material is poured in a thin stream back and forth from end
to end of the mold until it is more than level full.
4. It is leaved to cool at room temperature for 30 to 40 minutes and then it is
placed in a water bath maintained at the specified temperature for 30
minutes, after which cut off the excess bitumen by means of a hot, straight-
edged putty knife or spatula, so that the mold is just level full.
5. The brass plate and mold is placed with briquette specimen in the water bath
and it is kept at the specified temperature for about 85 to 95 minutes. The
briquette is removed from the plate; detach the side pieces and the briquette
immediately.
6. The rings are attached at each end of the two clips to the pins or hooks in the
testing machine and the two clips are pulled apart horizontally at a uniform
speed, as specified, until the briquette ruptures.
7. The distance is measured in cm through which the clips have been pulled to
produce rupture.
8. While the test is being done, the specimen both above and below by at least
25mm is covered with water in the tank of the testing machine and the
temperature is maintained continuously within ± 0.5°C of the specified
temperature.
Calculation:
Type of material Bitumen
Reading No. Ductility reading, cm Average reading, cm
1 109 106.5
2 104
Average reading = (104+109)/2 = 106.5cm
Conclusion:
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.
References:
1. http://www.prbdb.gov.in/files/Quality%20Control%20Training/Tests%20on%20Bitu
min/Ductility%20Test/DETERMINTION%20OF%20DUCTILITY.pdf
2. https://www.youtube.com/watch?v=TE8zYxUJHt0
