The Bitumen mode is dependent on temperature. The temperature-vs-stiffness relationship of bitumen is dependent on the type of crude oil and its refining method. Bitumen penetration grade 50/70 is semi hard penetration grade bitumen used as a paving grade bitumen which is suitable for road. It is also used for the production of asphalt pavements . This grade of bitumen is mainly used in the manufacturing of hot mix asphalt for bases and wearing courses. Bitumen 50/70 is one of the most used bitumen grades and it’s a basic material for all other bituminous products.
The penetration degree of 50/70 bitumen, which is provided by Dersa Bitoman Company, is pure petroleum bitumen, which is produced by passing hot air through the raw material of vacuum baton.
Bitumen is produced from crude oil residues after breaking down and eliminating its hydrocarbons.
The condition of refinery bitumen depends on its temperature.
The relationship between temperature and hardness of different types of bitumen depends on the type of crude oil and its refining method and the degree of permeability of bitumen is 50/70 between 5 to 7 mm. Are.
50/70 bitumen is used for asphalt production and is mainly used in hot asphalt production for surface coating.
The most commonly used type of bitumen is 70/50 bitumen and is a raw material for other bitumen products.
Bitumen with a penetration degree of 70-50 has a penetration degree of 5 to 7 mm and its soft point is between 49 to 56.
This degree of penetration of bitumen has a thermoplastic property that is similar to synthetic resin, it becomes softer with heating and hardens when cooled.
This grade of 70-50 bitumen has a very strong viscosity compared to other grades of bitumen and it is widely used.
Bitumen permeability test is used to determine the relative stiffness of blown bitumen and pure bitumen.
One of the uses of penetration grade is to specify pure bitumen and blown bitumen.
Pure bitumen is named only on this basis, but the criterion for naming blown bitumen, in addition to the degree of penetration of bitumen, is also the degree of thinness of bitumen.
For example, 70/50, 60-70, 85-100 bitumens and percent of bitumens are common pure bitumens in road construction.
Two numbers (50/70) that are associated with pure bitumen indicate that the degree of penetration of bitumen is in this range.
Bitumen R85 / 25, R90 / 15, R110 / 10 and… are common forms of blown bitumen in Iran, the first number indicates the penetration of bitumen and the second number indicates the soft spot of bitumen.
As explained, the degree of penetration of bitumen is the longitudinal value (in millimeters) of a standard diamond-shaped needle.
At a temperature of 25 degrees Celsius, it penetrates bitumen under a load of 100 grams for 5 seconds.