Bitumen is a mixture of organic liquids that are highly viscous,
black, sticky, entirely soluble in carbon disulfide, and composed primarily of highly condensed
polycyclic aromatic hydrocarbons.
It is principally obtained as a residual product in petroleum refineries after higher tractions
like gas, petrol, kerosene and diesel, etc., are removed generally by distillation from suitable
crude oil. Indian standard institutions define Bitumen as a black or dark brown
non-crystalline soil or viscous material having adhesive properties derived from
petroleum crude either by natural or by refinery processes.