Before knowing the difference between bitumen and tar; it is necessary to know what is bitumen and tar.
Bitumen is a solid or semisolid, black, sticky, ductile substance, obtained as an important byproduct from the distillation of crude petroleum.
Bitumen implies a group of hydrocarbon often mixed with some organic matter. It is known as petroleum in the fluid state, mineral tar in the semifluid state and asphalt in the solid state.
i. It is characteristically solid or semi-solid, black and sticky.
ii. It melts or softens on the application of heat.
iii. Its specific gravity is 1.09.
iv. It is completely soluble in carbon disulphide.
v. It is a binder in all types of asphalt.
vi. It possesses great chemical stability but is affected by oil.
vii. It has low permittivity and high insulation resistance.
i. It is used as a damp-proof course in walls and under basements and in lining tanks, swimming pools, urinals etc.
ii. Since it forms a good expansion joint, therefore, it is used for filling up the joints in leaky roofs.
iii. It is being extensively used as a road making material.
iv. It is used for making heat-insulating materials for buildings.
v. It is also employed in the manufacture of roofing felt, impermeable paints, and cold moulded bituminous plastics. Bituminous paints are made by incorporating red, green or brown pigments into the asphalt. These paints are suitable for decorative and waterproof flooring.
Tar is a black solid mass that is formed during the destructive distillation of coal, peat, wood, or other organic material. It contains 75 to 95% of bituminous contents. It contains a higher percentage of carbon.
Usually, tar properties depend upon the type of raw material used for manufacture, method of distillation and proportion of residual matter incorporated.
It hardens much quicker than asphalt. It is more adhesive than asphalt. It possesses toxicity to a high degree.
According to the American Society of Testing Materials, tar is a black or dark-brown bituminous condensate that provide substantial quantities of the pitch when practically evaporated or fractionally distilled and which is obtained by destructive distillation of organic material such as coal, oil, lignite, peat and wood.
It is the byproduct of the manufacture of bituminous coke and is soluble in carbon disulphide.
i. It is used for roofing and road making.
ii. It is used for making bituminous paints and water-proofing compounds.
iii. Coal tar is used as a preservative for timber.
iv. It is used for painting latrine walls.
3. Difference Between Bitumen and Tar
|1||It is usually solid.||It is a viscous liquid.|
|2||It is deep black.||It is jet black.|
|3||It has a low degree of toxicity.||It has a high degree of toxicity.|
|4||It is more adhesive.||It is most adhesive.|
|5||It consists of a moderate percentage of carbon.||It consists of a high percentage of carbon.|
|6||It is more resistive to water and acid.||It is less resistive to water and acid.|
|7||It sets quickly.||It sets slowly.|
|8||When it is spread, it loses volatile matter slowly and thus hardens slowly.||When it is spread, it loses volatile matter at a faster rate and thus hardens quickly.|
|9||It occurs naturally.||It is produced through distillation.|
|10||It is derived from sources associated with coal and oil.||It is derived from petroleum or coal and wood.|
|11||It has high durability.||It has less durability than bitumen.|
|12||It has high weather resistance.||It has comparatively low weather resistance.|
|13||It produces less deterioration than tar.||Greater deterioration is produced when exposed to weather conditions.|
|14||It has low specific gravity.||It has maximum specific gravity.|
|16||It produces a more slippery surface.||It produces a less slippery surface.|
|17||It has a low viscosity.||It has a high viscosity.|
|18||It is expensive.||It is cheaper.|
The use of bitumen or tar depends upon the conditions like strength, durability, cost, etc.
Bitumen is more flexible, durable & resistive towards chemicals. So, from the view of quality; bitumen is the best.
In terms of the economy; tar is more economical than bitumen.
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