15+ DIFFERENCES BETWEEN BITUMEN AND TAR USED IN ROAD CONSTRUCTION

difference between bitumen and taro
difference between bitumen and taro

Following are the differences between bitumen and tar.

  1. Bitumen has better weathering properties than tar. Generally, tar produces more degradation than bitumen when exposed to similar weather conditions. Bitumen has better durability and resistance to weathering than tar.
  2. Tars are more sensitive to temperature changes than bitumen. Hot weather will soften the surface of tar more than a surface made of bitumen of the same viscosity, and it will become more brittle at lower temperatures than bitumen. In other words, tar becomes brittle in cold weather and surfaces treated with tar are apt to bleed in hot weather if a small excess amount was used. Therefore tar is considered unsuitable for locations with wide temperature variations. Where bitumen has been used, but not with tar, there may be a slight delay in grating or surface dressing.
  3. Surface dressing with bitumen is more prone to failure from water displacement than with tar. Tar generally sticks better to wet aggregates than bitumen.
  4. The tar can be brought into a spraying state at a temperature lower than that required for bitumen; The stones do not need to be heated to high temperatures.
  5. Tar has a longer set time than bitumen and this property is useful in the production of pre-coated aggregates that can be transported over great distances or kept for a period of time before spreading.
  6. Tars harden much more quickly than bitumen.
  7. Tar has a higher specific gravity and lower viscosity than bitumen and these properties give them greater penetrating power and are more marked during the summer. Higher viscosity can generally be used with tar than with bitumen.
  8. Tar produces a less slippery surface than bitumen.
  9. Bitumen has a tendency to remain on or near the surface resulting in a rich and thick surface.
  10. Bitumen roads require constant traffic to keep them in good order; Otherwise the surface will crack and the life of the road will be reduced.
  11. Tar forms harder surfaces than bitumen (but such surfaces are brittle) and should be preferred for roads in areas where traffic with bullock carts or other hard tires is predominant. Bitumen forms a more elastic surface and is better suited for pneumatic traffic. The hardening of bitumen occurs very slowly.
  12. Tar is more suitable for dense fine-grained surfaces and bitumen for more open surfaces.
  13. The amount of tar required for the same type of road work is about 10 percent less than the amount of bitumen.
  14. Tar is cheaper than bitumen.
  15. Primer with tar is usually not needed.
  16. Road tar does not dissolve in petroleum distillates like petrol, kerosene, diesel oil. Thus tar carpets have proved to be a good material for parking lots as it is unaffected by oil and petrol leaks from automobiles.


Er. Mukesh Kumar

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Er. Mukesh Kumar is Editor in Chief and Co-Funder at ProCivilEngineer.com Civil Engineering Website. Mukesh Kumar is a Bachelor in Civil Engineering From MIT. He has work experience in Highway Construction, Bridge Construction, Railway Steel Girder work, Under box culvert construction, Retaining wall construction. He was a lecturer in a Engineering college for more than 6 years.