Generally speaking, viscosity bitumen grade is a substance suitable for
street paving, road construction and the asphalt pavement industry, especially
in areas such as India. Technically speaking,
Also , viscosity bitumen is mainly in the production of hot mixed asphalt for road paving, insulation and
the production of liquid bitumen. By combining the viscoelastic reaction
of bitumen with other materials, very flexible and viscous joints will appear
which depends on the speed at which the reaction applies. In the following,
we discuss more the viscosity bitumen grades production,
specifications, types such as VG 30, VG 40, VG 10 and other details.
Production and manufacturing viscosity bitumen grades
Important to know that viscosity bitumen, which is often a refinery bitumen,
is from vacuum aeration of the distillation tower, while refinery bitumen is
from the vacuum pulp of raw materials, which depends on the temperature
of bitumen. It’s also essential to know that bitumen in road construction if
it is from the mine, it is natural or mineral bitumen, and if it is from the refining
of crude oil, it is petroleum or refinery bitumen. To be more specific,
when crude oil volatiles in the depths of the earth evaporates overtime
against atmospheric agents, a black substance, which is natural bitumen, remains.
Natural bitumen includes rock bitumen and lake bitumen as follows:
In general, the bitumen types are all a type of natural bitumen. Besides,
bitumen is mainly limestone and sandstones into which crude oil has
penetrated and over time its volatiles has evaporated and bitumen remains
in these rocks. After crushing and softening, the bitumen heats and spreads
on the road surface. As a matter of fact, the amount of bitumen in rock
bitumen varies from 7 to about 80%. Good to know that bitumen dissolves
in mineral oils and solvents such as carbon sulfide, carbon tetrachloride
and ethylene trichloride.
What are the applications of viscosity bitumen grades?
The use of viscosity bitumen in road construction is not cost-effective
compared to the abundance of petroleum bitumen due to the high costs
of extraction and transportation, non-uniformity of constituents and the
variable amount of bitumen in them. Of course, future research can help
exploit and consume them in the road construction industry. Not to become puzzled, let’s discuss lake bitumen more.
Lake bitumen from a variety of natural bitumen
When crude oil naturally rises to the surface through the failed layers of the
earth and its volatiles evaporate, natural bitumen appears as a lake on the earth. Besides, lake bitumen resources are in most parts of the world, including
the Middle East. In fact, these resources are available in Iran, Poshtkuh,
Kharameh Fars and other regions of the country.
Types of petroleum bitumen in road construction
On the contrary, to the abovementioned, petroleum or refinery bitumen is
usually by refining crude oil in distillation towers, and ultimately what remains
at the bottom of the distillation tower is pure petroleum bitumen. Moreover,
bitumen types with different degrees of hardness for different road
construction use can be by adjusting the temperature and pressure inside
the distillation towers as well as aeration. Note that the bitumen from
crude oil refining is according to the type and conditions of their use
in road construction:
Pure bitumen from a variety of petroleum bitumen types
As you know, bitumen types that are directly from the refinery vacuum in
the something briefly exposed distillation tower or to the aeration process
are under the title of pure bitumen types. It’s important that these bitumen
types should be homogeneous and free of water and should not foam at 176 ° C.
In addition, pure bitumen types deform into a thick, watery liquid due to heat
and are elastic at low temperatures. As the last point, pure bitumen in
road construction divides according to penetration and performance.
Also , The technical specifications of bitumen for each project, depending on whether
they are bitumen with penetration or performance, should be clear in
the private technical specifications of the project.
Blown bitumen from various types of petroleum bitumen
So , Pure bitumen types pressurize to 200 to 300 ° C to combine all the hydrogen
in the bitumen molecules with oxygen in the air, and by creating
polymerization reactions, heavier hydrocarbons obtain that have a
lower penetration and a softer point than primary pure bitumen. In the Middle East,
two types of blown bitumen are 25.85 and 15.90, the numbers of 25
and 15 degrees of penetration and the figures of 85 and 90 are their soft points.
Soluble bitumen from various types of petroleum bitumen
The type and quality of soluble bitumen depend on the quality of the original
pure bitumen, the type and the amount of solvent. To put it differently,
the higher the number of petroleum solvents in the dissolved bitumen,
the greater its fluidity. In addition to above, the percentage of solvent
insoluble bitumen usually varies from 20 to 50%. Soluble bitumen is in
road construction for surface coatings, infiltration, surface asphalt,
cold factory asphalt, or mixed asphalt on-site, etc. Types of soluble
bitumen classifications are three major groups according to the set s
peed and the type of solvent.
- Instant soluble bitumen (RC)
- Solution bitumen (MC)
- Retardant Soluble Bitumen (SC)
To sum up, VG30, VG40, VG10 viscosity bitumen are more suitable for
But , In the classification based on the viscosity of
bitumen according to the absolute viscosity at 60 ° C or kinematic viscosity at
135 ° C, classification and specific technical criteria have been determined
for each of them. Absolute viscosity is clear in terms of motion
and kinematic viscosity.
To summarize, recycling asphalt pavement decreases construction expenses
as well as environmental depravity. Therefore, adding the bitumen emulsion
as a rejuvenator in aged and oxidized asphalt binder enhances its viscosity
and rigidity without significantly lowering the carbonyl ratio.