Ductility test for Bitumen

References:          AASHTO T-51       ASTM D -113

Definition:

This test determines the amount of Tensile  of bitumen ( normal or Modified), which is very important for Road designer to know how much is this value. The result of this test will show the amount of elasticity  and tensile strength of bitumen. increasing this value will results the good properties of bitumen and finally is better product for paving of road.

Instruments ( Apparatus):

1.ductility Machine           2.Balance         3.Oven            4.Speical Mold         5.Thermometer

Sampling:

Sampling of Bitumen is very like to Aggregate sampling ,but some points will be considered in bitumen testing ,such as position of sampling from the tank ,and or type and temperature of sample in time of sampling .and also must notice that if the sample is taken from a tank or directly from distillation oven.

Sample and instrument preparation:

It is very important that before starting the test ,some condition must be much to the general specification, like temperature of water in ductility machine, temperature of sample just before doing the test. all detail will come in procedure section.

Procedure:

First of all must arrange all equipment needed for the test. pour the clean water into ductility test machine and reach its temperature to 25 degree. also first of all  must put the sample  into oven for 10-15 minute or until flowing the bitumen by its weight. after that must fill three molds by this bitumen and lay down it in 4 degree water or letting that to get cool in room temperature for 15 minutes, then by a hot spatula of any sharp edge tool slightly remove the extra amount of bitumen from the edge of the molds. then must put them in warm water ( about 25 degree) ,for 15-25 minute and then put all three molds in machine and start it to stretch the molds by a speed of 5 cm per minute .and finally record the first ruptured distance of the mold from beginning .

this is the value of ductility of bitumen ,which report to supervisor as SI units or  US unit .but generally for normal bitumen samples ,the value less than 100  cm is called failed and above 100 cm is called as accepted or passed result.

You can also See Here Photo description of test  procedure of this test