Bitumen

            Bitumen is a mixture of Hydro carbons and thermoplastic material having strong tarry odour. It stiffness is dependent on temperature. The temperature-vs-stiffness relationship of bitumen is dependent on the source of crude oil and the method of refining. It also known as Asphalt and Mineral Pitch.

Bitumen has the following five characteristic properties.

*Bitumen Adheres
*Bitumen is Elastic
*Bitumen is Plastic
*Bitumen is Viscoelastic
*Bitumen Ages
*Bitumen Hardens

Properties of Bituminous Materials:

             The high demand of bituminous materials is owing to the number of their first-rate advantageous properties listed below:

1. Adhesive: Binds together all the components without bringing about any positive or negative changes in their properties.

2. Water proof: Bitumen is insoluble in water and can serve as an effective sealant

3. Strong: Though the coarse aggregates are the main load bearing component in a pavement, bitumen or asphalt also play a vital role in distributing the traffic loads to the layers beneath.

4. Durable: Bitumen lives upto twenty years if maintained properly throughout the pavement life.

5. Versatile: Bitumen is a relatively easy to use material because of its thermoplastic property. It can be spread easily along the underlying pavement layers as it liquefies when heated making the job easier and hardens in a solid mass when cooled.

6. Economical: It is available in cheaper rates almost all over the world