Specific Gravity Test of Bitumen
By the specific Gravity test of Bitumen, we are determining the specific gravity of bitumen that is one of the important properties of bitumen. Used for pavement construction is the classification of bitumen binders that can therefore be used.
The source of the bitumen binder can also help in identifying. In the bitumen specimen, the presence of the mineral impurities can also help in pointing out. If the mineral impurities quantity is more, then the value of specific gravity will increase.
From the bitumen binder during the extraction of impurities, it is very important. Instead of weight sometimes the volume of bitumen is specified, Presenting asphalt concrete mix design.
Apparatus OF Specific Gravity Test of Bitumen
For specific gravity tests of bitumen following are the instruments and apparatus used-
1. Specific Gravity Bottles
In this test, the bottles are used that are called wide-mouthed capillary type-specific gravity bottles. Whose neck diameter is 6 mm, that is called Ordinary capillary type-specific gravity bottles. In this ordinary capillary type-specific gravity bottle the materials are used that remain absolute fluid at 25 °C temperature.
Whose neck diameter is 25 mm, which is called a wide-mouthed capillary type-specific gravity bottle. In this ordinary capillary type-specific gravity bottle, the materials are used that remain highly viscous or semi-solid at 25 °C temperature.
The stopper is centrally located concerning the vertical axis. Its diameter is varying 1-2 mm. It is plain and smooth at the top and the lower surface is kept concave to escape from the bore to allow the air. At the center, the height of the concave surface is varying 4.0-6.0 mm.
3. Constant Temperature Bath
With 0.2 °C accuracies, the constant temperature bath should be maintained at the given temperature. That of pycnometer bottles, the depth should be greater than.
4. Bath Thermometer
For the measure of the temperature of water in the ductility apparatus bath thermometer is used. The range must be between 0 to 44 °C. The least count should be 0.1 °C
5. Other Apparatus
And the Other Apparatus That’s Being Used Is Below:
- Electronic balance
- Heating oven
Procedure of Specific Gravity Test of Bitumen
- At first, clean the specific gravity bottles and weigh them along with the stopper after they are dried. Note down this weight reading as And then one of the bottles was filled with distilled water and put on the stopper. Before filling the water should be cleanly boiled and cooled.
- After that minimum at 27 ± 0.1 °C and for at least 30 minutes in a beaker of distilled water up to its neck place the bottle on submerged. or at which any other temperature specific gravity is to be determined and can be maintained.
- With a dry cloth on the outside of the bottle clean the surplus moisture after Remove the bottles from the water bath. Again, measure the weight reading of the bottle. Note down this weight reading as After taking the weight reading the bottle should be dry again.
- By the application of heat carefully bring the bitumen specimen to a fluid state so that the material does not evaporate. After the step slightly warm the specific gravity bottle. Until half, into the dry and clean specific gravity bottle, pour the bituminous sample. Ensure that with the sides of the bottle the material does not come in contact.
- With the neck of the bottle, A small funnel can be used for pouring the materials which prevent the material from coming in contact. If there have any air bubbles the partly filled bottle to stand at 60-70 temperature so that the entrapped can escape.
- Up to the specified temperature allow the bottle to cool and weigh it. Note down this weight reading as Fill the bottle with freshly boiled distilled water that containing asphalt and loosely place the stopper. We should care that how to we can prevent air bubbles in the bottle.
- We need to attach the stopper firmly for at least 30 minutes and place the specific gravity bottle in the water bath. With a dry cloth on the outside of the bottle clean the surplus moisture after Remove the bottles from the water bath. At last measure, the weight reading of the bottle again and note down this weight reading as
Result of Specific Gravity Test of Bitumen
The specific gravity of the specimen is recorded as the ratio of the mass of an equal volume of distilled water to the mass of the specimen.
Within the range, the specific gravity of bitumen falls – 0.97 to 1.02 at 27 °C.
By Bureau of Indian Standard, the minimum specific gravity values standardized for Paving Bitumen at 27 °C for different grades that are given below:
Grade of Bitumen
|A – 25||0.99|
|A – 35||0.99|
|A – 45||0.99|
|A – 65||0.99|
|S – 35||0.99|
|S – 65||0.99|
|A – 90||0.98|
|S – 90||0.98|
|A – 200||0.97|
|S – 200||0.97|
Conclusion of Specific Gravity Test of Bitumen
Of bitumen practical by performing the specific gravity test, we can determine the given bitumen sample whether meets the specification requirements as given in the standards for specific gravity. By the compared to the standard value the specific gravity found out of the practical and thus the specific gravity criteria can be concluded whether the sample meets for the given grade of bitumen.