Bitumen Solubility Test With Video

The solubility test of bitumen is used to measure the percentage of soluble bitumen content in an organic solvent. Also, based on this test the bitumen purity is determined.

To perform the solubility test, bitumen is solved in a specific solvent. Then the mixture is filtered. After that, insoluble materials are washed, dried, and then weighed. A measure of how much bitumen dissolves in the solvent is reported as bitumen solubility.

See this test steps in the video below:

Different solvents can be used for this test. The most famous one is carbon disulfide, but generally, bitumen is soluble in carbon disulfide and trichloroethylene. 

Although these days use of carbon disulfide is becoming very rare because of its high flammability.  

Additionally, recent studies have shown that trichloroethylene can cause cancer and has been implicated in the destruction of the ozone layer. As a result, it is possible to replace trichloroethylene with a less harmful solvent.

What is the Significance of the Solubility Test of Bitumen?

Performing a solubility test on bitumen is a way to determine its purity.

It is essential to use a high quality bitumen in the road construction without impurity. Because bitumen becomes less applicable when it contains impurities. 

We do not have a uniform and stable asphalt using a bitumen binder which is less than 99% soluble in trichloroethylene.

The solubility of bitumen products in Infinity Galaxy is more than 99% and has high purity.

International Standard Methods for Solubility Test of Bitumen 

In terms of international standards for measuring solubility, the following methods can be used:

• ASTM D 2042
• AASHTO T 44 
• IS 1216
• EN12592
• IP47

Apparatus and Procedure of Solubility Test of Bitumen Based on ASTM D 2042

– Components of apparatus

1. Gooch Crucible
2. Glass Fiber rubber tubing
3. Filter Flask
4. Filter Tube
5. Rubber Tubing stopper
6. Erlenmeyer Flask
7. Oven
8. Desiccator

– Test steps

a) Preparation of Gooch Crucible

Place the gooch crucible and the glass fiber pad in the oven at 110 °C for 15 minutes to ensure that it is completely dry. Let them cool at room temperature. Weigh them and name this mass as A.

b) Sample Preparation

If the sample is not liquid, it should be heated to liquefy. The sample should not be heated more than 110 degrees Celsius above its softening point.

c) Procedure

1. Put 2g of sample in a container (ex: example 125 ml Erlenmeyer flask).
2. Let the sample cool at room temperature, then weigh it. Designate this mass as B.
3. In the next step, slowly add 100 ml of trichloroethylene to the container. Stir the container continuously while adding the solvent.
4. After the bitumen is completely dissolved put the stopper on top of the flask and leave it for 15 minutes.
5. Place the Gooch crucible in the filtering tube.
6. It is necessary to wet the glass fiber pad with trichloroethylene.
7. The solution is drained through the glass fiber.
8. To wash the insoluble matter within the Gooch crucible, add solvent. Once the solvent has become colourless, remove excess solvent using a suction. 
9. Remove the Gooch crucible and again wash the insoluble matter. Put it in a steam bath or an oven to dry.
10. Place the Gooch crucible in the oven a 110 °C for 20 minutes until the trichloroethylene evaporates.
11. Let the Gooch crucible cool in a desiccator for 30 minutes.
12. Finally, weigh its mass and designate it as C.
13. With the help of the following equations, the percentage of soluble and insoluble matter can be calculated:

Insoluble matter (%) = [(C-A)/B]*100

Soluble matter (%) = [(B-(C-A)/B)]*100

Where :

A = mass of crucible and filter

B = mass of the sample

C = mass of crucible, filter, and insoluble material