Bitumen, also known as asphalt, is a black, sticky, and viscous semi-solid or liquid form oil based substance. It is a semi-solid substance and is stable at ambient temperatures. There are six major kinds of bitumen according to their applications: paving grade bitumen, cutback bitumen, bitumen emulsions, modified bitumen, polymer modified binders and multi-grade bitumen.
Asphaltic bitumen is valued for a variety of properties. It is water-proof, ductile, adhesive, chemically inert, and resistant to atmospheric exposure and the effects of dilute acids and alkalis. Obtained from the residues of naphthenic crude oils after distillation of the volatile products, it is marketed in a wide range of grades, ranging from soft to hard.
Bitumen is manufactured through a fractional distillation process from selected crude oils. The crude oil is first heated to between 300°C and 350°C. The lightest fraction is then isolated through vaporization. Next, through the process of vacuum flashing or vacuum distillation of atmospheric residue from the vacuum distillation column, bitumen is obtained.
Building and constructions
The major use of bitumen is in construction industry as a binder involving roofing and paving applications and around 85% of bitumen produced in the world is used for road construction, car parks, airport runways and footways. It is also used as a binding agent to mix sand, gravel and crushed rock. It can also be used for bituminous waterproofing products.
Paint and Coating
Asphalt or Bitumen also is used in paint and marker inks by some graffiti supply companies to increase the weather resistance and permanence of the paint and ink, and to make the color much darker.