Regarding its generation source bitumen can be classified into three categories:
natural, petroleum asphalts, coal tar pitches:
A- Natural bitumens or native asphalts are a class of bitumens which have been
naturally produced due to climate conditions in the course of time, and are used
without the need to be processed in distillation ways; they are very varied regarding
their composition and properties.

B- Coal tar Pitches are hard black substances which are formed as the result of
coal tar distillation. Their new broken surface is shiny and when they are heated
they , along with fast decrease in viscosity, melt and their melting point depends on
the production process.

C- Petroleum Asphalts are the bitumens which are derived from petroleum
.These are solid and semi solid bitumens which are directly produced through
distillation from petroleum or by additional operations such as air blowing. Compared
with the other types, they are more commonly used and have more applications.