All-day to day activities require a lot of time, energy, effort and most important materials. Construction of anything, be it roads, parking lots, runways, footpaths, garages etc require various substances. All these substances vary in their features, characteristics, appearance, usage and so on.
Different materials play different roles in various processes. The materials required are unique in their own ways. One material cannot be used in place of the other because each material has its own integral role to play.
Among the various substances, Bitumen and Tar are the most commonly used and known substances. Both these substances are used very often in the day to day activities. They have various purposes that they help in.
Bitumen vs Tar
The main difference between Bitumen and Tar is that Bitumen is derived from sources likes coal and oil and exists in usually in solid form whereas on the other hand Tar is derived from sources like petroleum and wood and exists usually in the liquid form.
Comparison Table Between Bitumen and Tar
| Parameter of Comparison | Bitumen | Tar |
|---|---|---|
| Derived from | Bitumen is derived from sources associated with coal and oil. | Tar is derived from sources associated with petroleum and wood. |
| Exists in | Bitumen exists in the solid form. | Tar exists in viscous liquid form. |
| Colour | The colour of Bitumen is dark with slight reddish. | The colour of Tar is deep dark. |
| Nature | Bitumen occurs naturally. | Tar usually needs to be distilled. |
| Carbon Content | The carbon content of Bitumen is medium. | The carbon content of Tar is very high. |
| Setting Time | The setting time of Bitumen is very less. | The setting time of Tar is more. |
| Cost | Bitumen is more expensive as compared to Tar. | Tar is cheaper as compared to Bitumen. |
| Molecular weight range | The molecular weight range for Bitumen is 400 to 5000. | The molecular weight range for Tar is 150 to 3000. |
| Resistance to weather | Bitumen is more resistance to weathering action. | Tar is less resistance to weathering action. |
| Used for | Bitumen is used in construction as damp-proof course and roofing felt. | Tar is used in industries and usually for preserving timber. |
| Temperature susceptible | Bitumen is less susceptible to temperature. | Tar is very susceptible to temperature. |
What is Bitumen?
Bitumen is a very commonly used substance. It is a mixture of various organic substances. It consists of aromatic hydrocarbons. Bitumen occurs in the solid-state. It is dark in colour and is viscous. Bitumen is often referred to as asphalt in a few countries.
Bitumen is formed in an environment with lots of algae, plants and other such organic matter. It is due to this, that Bitumen is also formed in similar conditions like oil and coal. It is formed in mainly in lakes and marshes. Areas of high vegetation wherein it is possible to preserve the plant matter in mud deposits, are also where it is possible for the formation of Bitumen. The plan matter is preserved in mud deposits and is altered because of heat and pressure when it gets buried. Organic shale is the main source of Bitumen.
Bitumen has a better weathering property. They are durable and resistant to weathering conditions. Also, bitumen has a tendency to stay at or near the surface. This usually leads to the building up of a rich and fat surface.
It is because of this reason that there has to be regular traffic on roads built of bitumen so that the roads can be kept in good order. If this is not the case, it results in the cracking of roads and reducing the life of the roads.
What is Tar?
Tar is another very common substance that is used in various day to day activities. It is most commonly used as a sealing agent. It helps seal roof tiles, building interiors and boats. It is also used as a flavour in candy and various foods. Because of the pleasant smell of Tar, it is often used in cosmetics too.
So basically, Tar is a black liquid which can be formed in different ways. It is made of hydrocarbons mostly. But since Tar is formed in various ways, the chemical composition of Tar also varies. Mostly Tar is made of some kind of organic matter.
Tars are highly susceptible to temperature changes. With hot weather, the surface of Tar softens while it becomes brittle at low temperatures. This makes it unsuitable for Tar to be used in places where there are many temperature fluctuations.
The specific gravity of Tar is also very high and the viscosity is low. Tar has great penetrating power. One of the main reasons that Tar is commonly used is because it is very affordable as compared to the other likes of it.
Main Differences Between Bitumen and Tar
- Bitumen usually exists in the solid form whereas on the other hand Tar exists in the liquid form.
- Bitumen comes from sources like coal and oil whereas Tar comes from sources like wood and petroleum.
- Bitumen occurs naturally whereas on the other hand Tar needs to be distilled.
- The carbon content of Bitumen is medium whereas, on the other hand, the carbon content of Tar is very high.
- Bitumen costs more than Tar while Tar costs less than Bitumen.
- Bitumen has less temperature susceptibility whereas on the hand Tar has more temperature susceptibility.
- Bitumen is more resistance to weathering action whereas Tar is less resistance to weathering action.
Conclusion
Bitumen and Tar are two different substances that are often used in the day to day activities. They do have quite a few similarities between them like, both of them are dark organic liquids. Both of them seep from the ground.
Bitumen and Tar are very often used in the same areas as both as used for sealing in the process of construction.
However, there are major differences between the two. Bitumen usually exists in the solid-state while Tar exists in the liquid state. Also, bitumen mostly occurs naturally while Tar needs to be distilled.
References
- https://www.onepetro.org/journal-paper/SPE-10229-PA
- https://pubs.acs.org/doi/abs/10.1021/ef9009586