Bitumen 60/70 and 80/100 are two widely used grades in road construction and asphalt industries. Each of these bitumens has unique characteristics that are more suitable for certain climatic conditions and projects. In this article, we will examine the differences, similarities and applications of each of these grades.
Definition
Bitumen 60/70
This grade is placed in the category of medium penetrating bitumen and due to its relative hardness and suitable flexibility, it is considered one of the most used grades in asphalt construction. The number “60/70” indicates the penetration range of bitumen at 25°C (between 60 and 70 tenths of mm).
Bitumen 80/100
This grade is softer than 60/70 bitumen and is usually used for areas that require more flexibility. The permeability of this bitumen at 25 degrees Celsius is between 80 and 100 tenths of mm.
Important differences
Hardness and flexibility
Bitumen 60/70 is harder than bitumen 80/100 and is more resistant to deformation at high temperatures. 80/100 bitumen is more flexible due to being softer and causes less cracking at low temperatures.
Resistance to temperature
Bitumen 60/70 is more stable at high temperatures and is more suitable for areas with hot summers. Bitumen 80/100 performs better at low temperatures and is more useful in cold regions where there is a possibility of freezing and thermal expansion.
Applications
Bitumen 60/70 suitable for busy roads, highways and areas with heavy traffic. Bitumen 80/100 is a suitable choice for low-traffic roads, rural areas and projects that require more flexibility.
Climatic conditions
Bitumen 60/70 in tropical and temperate conditions
Bitumen 60/70 is harder than bitumen 80/100 and has more stability at high temperatures.
In tropical regions where temperatures rise sharply, the softer bitumen may loosen and cause permanent deformation of the asphalt surface (such as rutting). Bitumen 60/70 avoids this problem due to its higher hardness.
Roads under the pressure of heavy traffic (such as highways and busy urban areas) at high temperatures require bitumen with high resistance. 60/70 bitumen is ideal for such applications.
In tropical regions, the temperature difference between day and night is usually not large. This reduces the possibility of thermal cracking, which 60/70 bitumen does well.
Bitumen 80/100 in cold and moderately cold weather conditions
80/100 bitumen is softer than 60/70 bitumen, so it has more flexibility at low temperatures.
In cold regions, hard bitumen can become brittle and develop fine cracks or deep cracks, but 80/100 bitumen avoids these problems by being more flexible.
In cold regions, temperature changes between night and day or winter season can cause the asphalt layer to contract and expand. Bitumen 80/100 can tolerate these changes better and prevent cracking.
In areas where there is snowfall or freezing, the flexibility of 80/100 bitumen helps prevent damage from the deicing cycle.
Conclusion
The difference between 60/70 and 80/100 bitumen is their penetration rating, which indicates the hardness and acceptability of the bitumen. 60/70 bitumen is harder and less permeable, so it is more suitable for areas with high temperatures or under heavy traffic, as it provides greater thermal resistance and strength. In contrast, 80/100 bitumen is softer and more consumable and is suitable for cooler areas, as it does not crack at lower temperatures.
to make the right choice between 60/70 and 80/100 bitumen, one must consider the type of project, weather conditions, and costs.
Both grades may be suitable when the project is in a temperate climate. But factors such as the type of traffic load, costs and project priorities can play a role in the final decision.
