Bituminous materials are a class of hydrocarbon mixtures that are semi-solid or liquid and are usually dark brown or black in color. They come from synthetic or natural processes and are classified as thermoplastics. This procedure produces a denser residue by removing volatile components. Rock and petroleum deposits that have weathered and been exposed to the elements over time can yield natural bitumen’s.Bitumen is an important part of any road surface and is used all over the world. It can be regarded as the building block of the pavement. The primary reason which makes bitumen a viable choice in flexible pavements is that it binds the other pavement components. Furthermore, it results in a smooth pavement free from defects for the moving movement of vehicular traffic. Bitumen, although a natural substance in solid and semi-solid petroleum, can be readily obtained by fractional distillation of petroleum.
