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Evaluation of Bitumen Concentration

Evaluation of Bitumen Concentration

If you are with us by the end, we will provide you with information about the concentration of bitumen.

Bitumen is solid. People use it in insulation and asphalt construction. This material is produced in different ways that each of them has its own efficiency.

Pitch is a derivative of oil. The color of this material is black to dark brown and they dissolve it in carbon tetrachloride/ carbon disulfide.

People produce tar in two ways. If people extract pitch from the mine, it will be mineral pitch.

It will be oil tar, if they extract it from the oil refinery.

The application of mineral pitch includes road construction and sealing of buildings.

Superior Characteristics of Pitch

Tar has superior features such as water permeability, high adhesion to other materials, electrical insulation, elasticity and moderate stability against acids, bases as well as salts.

Disadvantages of Pitch

It has disadvantages such as loss of physical and mechanical properties due to rising temperature,  turning  it into charcoal due to high heat, loss of adhesion, deformation due to high pressure, dissolves in some solvents such as carbon sulfur and mineral oils as well as loss of adhesion in contamination of the soil and wet environment.

How to Create Pitch

People distil crude oil to produce oil pitch.

We can say that one of the products of the atmospheric distillation tower is tar. Humans separate gasoline from crude oil in the first stage of distillation – whose pressure is about an atmosphere.

They also separate gasoline and kerosene from crude oil in the second phase of distillation –which its pressure is close to the vacuum- and finally a mixture of fine asphalt particles remain.

Lab Tests on Pure Pitch, Soluble Tar and Emulsion Bitumen

Pure Pitch

Degree of   Penetration

If you want to determine the concentration of pitch, they can use the degree of penetration. You must use a standard needle to do so.

Your needle should be pregnant and also weigh 100 grams. You need to put it in tar- the temperature is 25 degrees Celsius- for five seconds to do it.

If its penetration is less, the hardness of tar will be more.


The solid properties of pitch are more, if the viscosity of tar is higher.

As a result, the density of bitumen is lower at higher temperatures.

Degree of Ignition

When individuals raise the temperature of tar to that degree, the emissions are ignited. You can heat tar according to its degree of ignition.

Losing Weight

If you evaporate some oils and oil compounds, the weight of bitumen will decrease. You can measure it at 163 degree Celsius and within 5 hours in Avon.

Degree of Purity

The measurement includes pitch sample weight, amount of impurity and tar weight.

Soft Spot or Degree of Softness

If they convert pitch from solid to smooth state, it becomes soft. As a result, it is less sensitive to temperature changes.

The softness of conventional tar is 60-70 degrees Celsius

Bitumen  Emulsion

 The experiments of components of tar emulsions include the determination of residual pitch from distillation, determination of residual due to evaporation and etc.

The tests of determination of concentration of tar emulsions include the determining the viscosity or viscosity of tar emulsions by Saybolt Furol viscometer.

The tests of determination of stability of bitumen emulsions include conglobate, loosening & storage, cement mixing, freezing, coating testing and etc.

We conduct experiments on the density of residual pitch from tar emulsion distillation as follows:

Determination of penetration rate, ductility, determination of tar solubility in trichloroethylene and etc.

Soluble Bitumen Concentration

If people want to produce soluble pitch, they can dissolve pure bitumen with solvents or petroleum products oils, so their type and quality are directly related to the type of solvent and the amount of dissolver.

If the amount of oil solvents is high in soluble tar, the density of tar is lower.

People use soluble pitch in road construction for surface plates, cold asphalt of factories or asphalt mixtures in place due to the lack of access to asphalt heating devices, the decomposition of tar at high temperatures, the impossibility of water penetration in porous minerals, the safety of workers and etc.

In fact, People divide soluble bitumen of the following three categories according to the speed of the clamping and the type of solvent:

Rapid curing (RC), medium curing (MC) as well as Slow curing (SC).

The tests performed on soluble pitch include determination of kinematic viscosity at 60 degrees Celsius in CST, determining the flash point by open cup method, determining the percentage of water as well as determining the percentage of residual tar by distillation method.

Thickener for Pitch Emulsion

The amount of viscosity in tar used in surface repair is very important in terms of spraying, but it is impossible to measure.

If the tar has a high shear mixer and a temperature of 90 degrees Celsius in terms of spraying, they will break.

They are desirable in terms of practice, but those are inappropriate in terms of rheology.

If the concentration of pitch emulsion is high, it will have very few Newtonian viscosity properties because their viscosity will change because of the cutting speed.

As a result, it will have different temperatures.

Emulsifier plays an important role in the production of emulsion bitumen, but it cannot increase the density of pitch to the extent possible.

As a result, people use additives such as thickener for tar emulsion.

Thickener for tar bitumen is effective on water in emulsion. It increases the density of cationic pitch emulsion.

Emulsion tar has low viscosity that according to regulation 234 paving, viscosity must be between 100-20, but sometimes the viscosity is less than 20.

If humans want to increase viscosity, they can add thickener to the concentration of pitch emulsions.


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