The uses of bitumen
The
most amount of bitumen, which is used in the construction industry and road construction,
is also used in road and roof pavement. The waterproofness and elasticity at
high temperature are two perfect traits of bitumen that makes it ideal for a
vast group of uses. It works like an adhesive liquid at high temperatures
(normally between 100°_ 200°) and it can get mixed with the other components
and get shaped if needed. An ineffective solid material will be remained after
cooling down which is tough and hydrophobic (it repels water). Several terms
are used to describe normal bitumen such as pavement grade, penetration grade,
and pen grade (also known as PG). When they use these terms they usually mean a
bitumen that can be produced in an ordinary refinery by relatively simple
methods. The refinery processes that are used to produce bitumen and the effect
of these processes on final specifications of the product are mentioned in
several sources.
What is pure bitumen?
Since
the most amount of bitumen that is used in asphalt for road construction is the
normal bitumen (pure bitumen), it is mostly known as the asphalt bitumen.
The
term "penetration grade" is the short form of bitumen with
penetration grade, and it shows the fact that this product is usually
classified by the penetration test (in Europe and some parts of Asia). The term
"direct extraction” mentions the fact that this type of bitumen directly
gets produced by the vacuum distillation process and without further reforms. The
available estimations of global bitumen usage are nearly 102 million tons of
bitumen in a year (according to Euro Bitumen and Asphalt Institute 2011) and
about %85 of the entire amount of produced bitumen is used for road
construction and other asphalted areas. Normally, asphalt contains %5 bitumen
and the remaining %95 is a mixture of mineral gravels and fine grains like
limestone filler.
"Asphalt"
is a common term used to describe a large number of road pavement products
which contain bitumen and mineral gravels. There are some superseded terms like
hot mix asphalt (HMA) and asphalt concrete (AC). In this essay, the term "asphalt"
is used in all meanings. The term "asphalt is usually misused in media as
the short form of asphalted road.
Sale of export bitumen
Asphalt
road pavement is a part of the road that has been used as a connection by coal
tar and it's nearly more than 30 years that it isn't used anymore.
Coal tar (bitumen)
%10
of global tar production is used in roof pavement and near %5 of it is used in
sealing and insulation at different kinds of building materials like pipe covering,
covers protection, connections sealing, and dye preparation.
A vast field of Bitumen
uses is
shown by the recorded use cases in Europe, matching with regulatory
requirements of registration, evaluation, authorization, and Restriction of
Chemicals (REACH) that needs to list all the chemical materials and
related expenditures.
Bitumen is available in
variable grades. Characteristics all around the world are used to describe
these grades that meet the needs of applications, the climate, loading
conditions, and the final use. They usually are based on some experimental
standard methods which define the same properties of each grade; like hardness,
viscosity, solubility, and persistence. Bitumen is also is used to produce a
mixture or for bedding. In these products, bitumen is usually the major part
however they can contain a considerable proportion of other materials in order
to meet the needs of final use. These mixtures are classified as kinds of
bitumen.
The most common ones
are mentioned below (Eurobitume and Asphalt institute 2011).
The soluble bitumen and
oil modified bitumen
The soluble bitumen and oil-modified bitumen are two products
in which the viscosity of the bitumen is reduced by adding a solvent (usually a
hydrocarbon).
Normally, the used solvents are white
spirit, materials similar to white oil and petrol. The bitumen products are
usually used for dispersal and mixing, in some cases.
Types of soluble bitumen
The modified bitumen
The polymerized-modified bitumens (PMBs) are
produced to change the characteristics and function of the directly extracted
bitumens Properties like elasticity, adherence, and the durability of
adherence. This type of bitumen can be modified by one or more than one
chemical substance. These substances may contain polymers, waxes, shredded
rubbers, sulfurs, and acids. The modified bitumens have reached different uses
by now.
The Emulsion bitumen
The emulsion bitumens are those types of products
in which the bitumen particles are outspread in a water phase. Emulsifiers are
used to stable the mixture. Bitumen emulsions provide the possibility of
transporting and using the bitumen at temperatures which are lower than the temperature
of the bitumen and they are usually used for road pavements. You can find more
information about bitumen emulsion and the way to use them in the other parts.
Components of emulsion bitumen
What is bitumen?
Introduction of different bitumen experiments