How to choose the best Grade of PG Bitumen?

For the chosen grade of PG, Bitumen should consider stress-strain relationships under field loading, pavement conditions like temperature, traffic speed, volume, and structure, and acceptance limits derived from experience and actual field performance.

Variables affecting binder selection include geographic area, air temperature, pavement temperature, traffic volume, speed, and pavement structure.

PG Bitumen in Different seasons

In PG Bitumen with two positive numbers A negative number is defined in which a positive number corresponds to the average of seven consecutive days of the highest pavement temperature in the summer season and a negative number is the minimum pavement temperature in seven consecutive days of the winter season in degrees Celsius.

the feature of PG Bitumen Grades

the best grade of PG Bitumen for resisting thermal cracking:

1. PG 64-22
2. PG 76-22
3. PG 64-28
4. PG 58-34

the best grade of PG Bitumen for resisting rutting:

1. PG 82-22
2. PG 76-28
3. PG 70-28
4. PG 76-22

the best grade of PG Bitumen for Traffic Speed

1. PG 58-22
2. PG 64-22
3. PG 70-22
4. PG 76-22

4 Key Factors for Selecting PG Bitumen

1. Traffic Conditions

PG bitumen selection is crucial for roads with high traffic volume and heavy vehicle loads, as it affects its resistance to deformation and fatigue cracking. High traffic areas require bitumen that can handle repeated loading without significant deformation, such as higher PG grades or polymer-modified bitumen (PMB). Lower-speed traffic increases the time under load, making rutting more likely. Roads with high heavy axle loads require bitumen with enhanced rutting resistance and fatigue performance.

2. Moisture Susceptibility

In regions with high rainfall, humidity, or water accumulation, selecting bitumen with good moisture resistance is crucial. Bitumen should be resistant to stripping to maintain pavement integrity. Anti-stripping agents or polymer modification can enhance moisture resistance.

3. Aging Resistance

Bitumen ages due to oxidation, UV exposure, and environmental factors, causing brittleness and reduced pavement life. PG bitumen is chosen to minimize aging effects by using additives or higher oxidation resistance. Long-term pavement durability is crucial, especially in regions with high UV exposure or temperature fluctuations.

4. Cost Considerations

Choosing PG bitumen involves balancing initial cost with expected performance and maintenance costs. Higher-grade and modified bitumen types are more expensive but may reduce long-term maintenance and repair costs by extending pavement life.

The Main Application of Performance Grade

Performance Grade Bitumen mainly used for Road Construction or paving for both new construction However Other uses include spray applications for bridge deck and pavement protective membrane with fabrics.

Equivalence of Bitumen Penetration to Performance Grade Bitumen

The bitumen penetration produced in the country’s refineries can be classified into two standard categories: 60/70 and 85/100 or 80/100.

• Bitumen 60/70 produced by refineries with a penetration degree of 64.7 is equivalent to bitumen PG 64-22 and PG 64-10 in the SHRP classification.PG bitumen named PG6422 and PG6410 performs almost the same function as Bitumen 60/70.The meaning of the numbers in front of PG, such as PG 64-22, is that the bitumen performs well from -22 to +64 degrees Celsius and PG 64-10 that means Bitumen Performs well from -10 to +64 degrees Celsius.
• Bitumen 85/100 or 80/100 produced by refineries with a penetration degree of 95 is equivalent to PG58-22 bitumen in It will have SHRP rating.PG 58-22, it means Bitumen Performs well from -22 to +58 degrees Celsius.

Performance Grade Bitumen for East Asia

PG Bitumen is a classification system for bitumen (asphalt) used in road construction, based on its performance at varying temperatures rather than just its penetration grade. For East Asia, which includes countries like China, Malaysia, Thailand, Taiwan, Vietnam, Philippines, Indonesia, and Cambodia.

Commonly Used PG Grades in East Asia

• PG 64-22:

  • Suitable for moderate climate zones with average high and low temperatures.
  • Widely used in many parts of East Asia where temperatures do not exceed 64°C (147°F) and do not fall below -22°C (-8°F).

• PG 70-22 / PG 76-22:

  • Used in regions with higher summer temperatures or more severe traffic conditions.
  • PG 70-22 can withstand higher pavement temperatures up to 70°C (158°F), while PG 76-22 is suitable for even hotter climates or where enhanced performance is required.

• PG 58-28 / PG 64-28:

  • Used in colder regions, particularly in Northern China, where winter temperatures can drop significantly.
  • These grades can withstand lower temperatures, preventing thermal cracking.

Performance Grade Bitumen in Africa

Performance Grade (PG) Bitumen in Africa is chosen based on the continent’s diverse climate conditions and traffic demands. Africa’s geography ranges from hot desert climates to tropical and temperate regions, so the appropriate PG bitumen must be selected to meet the specific temperature and environmental conditions of each region.PG Bitumen can be exported to various regions in Africa, such as Congo, Djibouti, Rwanda, Angola, Kenya, Liberia and Mozambique.

Most Usage of PG Bitumen in Africa

• PG 64-16:

  • Suitable for moderate climates with average high temperatures and minimal low-temperature requirements.
  • Commonly used in areas with temperatures not exceeding 64°C (147°F) and rarely dropping below -16°C (3°F).

• PG 70-10 / PG 70-16:

  • Used in hotter regions such as North Africa, parts of West Africa, and Southern Africa.
  • These grades are designed to handle higher temperatures up to 70°C (158°F) while preventing rutting and softening.

• PG 76-10 / PG 76-16:

  • Often used in regions with extremely high pavement temperatures or heavy traffic, such as urban centers or high-volume highways.
  • Can withstand temperatures up to 76°C (169°F), making it suitable for hot climates.

• PG 58-22:

  • Used in regions where lower temperatures are experienced, such as highland areas or regions closer to the Mediterranean coast.
  • This grade can handle moderate temperatures while providing flexibility to resist cracking at lower temperatures.

Specifications of Performance Grade Bitumen

In Summary

Performance Grade Bitumen (PG Bitumen) is a popular product for road construction, used in various weather conditions. It is classified into Low, Medium, and High temperatures, with specifications based on AASHTO M 320-10 and ASTM D6373 − 1. The PG system uses a common battery of tests to determine the performance of a particular asphalt binder at specific temperatures. For high temperature performance, rutting takes time to cumulate, while low temperature performance can cause thermal cracking. The best grade of PG Bitumen for resisting thermal cracking is PG 64-22, PG 76-22, PG 64-28, PG 58-34, PG 82-22, PG 76-28, PG 70-28, PG 76-22, and PG 58-22. PG Bitumen is mainly used for road construction, paving, spray applications for bridge decks, and pavement protective membranes with fabrics.