bitumen is a sticky, black and highly viscous liquid or semi-solid that is present in most crude petroleums and in some natural deposits. Until the 20th century, the term Asphaltum was also used.It is most commonly modelled as a colloid, with asphaltenes as the dispersed phase and maltenes as the continuous phase

Oxidized bitumen is produced by either continuous or Staggered Blowing Process. Heated Penetration Grade bitumen under controlled environment is blown with air which controls the oil content in the bitumen while it oxidized. The different grades for suited applications produced are designated by two numbers to indicate the mid-points of their softening point and penetration ranges.