Performance grade bitumen

How is performance grade bitumen different? Why is PG bitumen an important and concise type of bitumen? Bitumen is commonly classified by penetration degree (hardness) and viscosity (consistency) While SHRP engineers later recognized that temperature significantly affects bitumen performance. This leads to the development of the SUPERPAVE system.

What is performance grade bitumen?

Performance Grade Bitumen is a climate-specific asphalt, classified under HS code 27132000, made of carbon, hydrogen, sulfur, and trace elements, with no specific chemical formula or CAS number.

PG bitumen, is graded based on its performance across different temperature ranges, ensuring reliability in extreme conditions. PG Bitumen is designed to withstand high traffic and harsh climates. At high temperatures, it resists rutting and deformation, with grades ranging from 16 to 46—higher values indicate better performance.

At low temperatures, performance grade bitumen ensures resistance to cracking and stiffness, with grades from -22°C to -76°C—lower values signify better cold performance.

PG grading system

After years of research, SHRP engineers identified temperature as a crucial factor in bitumen performance, which earlier classification systems had overlooked. This led to the development of the SUPERPAVE system (Superior Performing Asphalt Pavements) between 1987 and 1993, introducing the Performance Grade Bitumen system.

This system evaluates binders based on their performance in extreme temperatures, ensuring suitability for specific environmental and traffic conditions through standardized, performance-linked tests.

The Long-Term Pavement Performance (LTPP) program contributed an algorithm, the performance grade bitumen calculator, to aid in the selection of appropriate binders.

The PG Bitumen grading system classifies bitumen based on its performance at low, medium, and high temperatures, indicating the temperature range where it performs effectively.

• The positive number (e.g., 58) represents the average maximum pavement temperature over seven consecutive summer days.
• The negative number (e.g., -28) indicates the lowest pavement temperature during seven consecutive winter days.

Types of PG bitumen

Performance Grade Bitumen is designed for specific climates and traffic conditions, ensuring durability in various temperatures. The PG grading system classifies bitumen based on high and low pavement temperatures.

For example, PG 52-28 is ideal for cold climates, while PG 76-22 resists rutting in hot climates. PG bitumen offers superior resistance to fatigue cracking, adhesion, and weathering, ensuring long-lasting infrastructure. These features affect performance grade bitumen price.

This type of bitumen is divided into modified and unmodified types:

Modified

Polymer-modified binders improve the performance of PG bitumen by offering better resistance to rutting, cracking, and fatigue. To identify them, add the high and low-temperature grades—if the sum exceeds 92, the binder is likely polymer-modified. For example, PG 76-22 (sum: 98) is polymer-modified.

Polymer modification in performance grade bitumen, improves bitumen’s resistance to deformation and cracking in extreme conditions, but also raises its price.

Features	Details
Performance	Better resistance to rutting, cracking, and fatigue
Temperature Suitability	Works in hot and cold climates
durability	Higher durability resists aging.
Adhesion	A stronger bond reduces stripping.
cost	Higher cost due to additives
Applications	High-traffic areas, extreme climates

Unmodified

Unmodified performance grade bitumen refers to bitumen that hasn’t been enhanced with additives like polymers to improve its performance. It is typically used in areas with moderate climate conditions where extreme temperature fluctuations or heavy traffic loads are not a concern.

If summing the high and low temperatures is below 92, it is unmodified. For example, PG 64-10 (sum: 74) is unmodified.

Feature	Details
Temperature Suitability	Graded for specific temperature ranges, e.g., PG 64-10 (max 64°C, min -10°C). Suitable for typical conditions.
Cost-Effective	Unmodified performance grade bitumen cost is more affordable than modified bitumen and is ideal for budget-conscious projects.
Performance	Adequate for standard road construction but less resilient in extreme climates and high-traffic areas. Prone to rutting and cracking.
Applications	Used in mild climates, lower traffic volumes, and moderate weather; common in maintenance and repair work.

Performance grade bitumen uses

Performance Grade Bitumen is a modern classification system designed to assess bitumen performance across specific temperature ranges. This method evaluates mechanical properties, making it easier for consumers to select the appropriate product for their needs.

Suitable for both polymer-modified and pure bitumen, PG bitumen grades are determined based on environmental and temperature conditions. A wider performance grade bitumen grade range indicates greater durability and improved performance characteristics.

This type of bitumen is highly used in flexible pavement. Using this special type of bitumen can lower rutting, thermal cracking, Fatigue or alligator cracking, bleeding, block cracking, corrugation and shoving, depression, joint reflection, and longitudinal cracking.

Because rutting and thermal cracking are two main road damages, the suitable PG bitumen grades to use in the flexible pavement to maintain the surface are as below.

Performance grade bitumen grades for preventing thermal cracking include PG 58-34, PG 64-22, PG 64-28, and PG 76-22. This type of bitumen grades resistant to rutting include PG 70-22, PG 70-28, PG 76-28, and PG 82-22.

PG Grade	Primary Applications	Climatic Suitability	Performance Strength
PG52-28	New construction, HMA, sealing, spray applications	Moderate climates	General-purpose binder
PG58-22	Bridge decks, protective membranes, HMA	Moderate climates	Versatile for dense/open-graded HMA
PG58-28	HMA, cold climate spray applications	Very cold regions	High resistance to thermal cracking
PG58-34	High-elevation, cold-weather HMA	Extremely cold climates	Superior thermal cracking resistance
PG58-40	High-elevation HMA and sealing	Extremely cold, high-altitude areas	Excellent for extreme cold temperatures
PG64-22	Toll roads, bridge decks, protective membranes	Moderate climates	Reduces pavement tenderness, versatile
PG64-28	Eastern Washington (lower half), HMA, sealing	Cold climates	Reliable in low-temperature areas
PG70-22	High-traffic areas, toll roads, urban highways	High temperature, heavy traffic	Superior rust resistance
PG76-22	Rest areas, toll booths (slow traffic)	High-stress, heavy-traffic zones	High durability for standing and slow traffic
PG82-22	Heavy-duty roads, extreme traffic	High-temperature areas	Best rut resistance

PG grade asphalt specification

Bitumen PG 64-22 (asphalt) is a Performance Grade bitumen that is categorized based on its behavior at various temperatures. How to determine PG grade of asphalt? The grading of PG bitumen depends on two main factors: traffic conditions and pavement temperatures.

The process for determining the PG grade of asphalt:

Step	Description
1. Consider Key Factors	– Traffic loads: Higher traffic = higher PG grade.
	– Climate: Hot climates = higher high-temperature grades; cold climates = lower low-temperature grades.
	– Pavement design: Review thickness and structure.
2. Laboratory Testing	– DSR Test: Assesses high-temperature performance.
	– BBR Test: Assesses low-temperature performance.
3. Select PG Grade	Choose the appropriate grade based on test results and project requirements.
4. Verification	Ensure PG grade meets specifications during production and construction.

Adjustments to the PG 64-22 asphalt specification are made to improve the pavement’s durability and design life, taking into account traffic volume and temperature extremes of 64ºC and a minimum of -22 ºC, over 7 days, making it suitable for use in very cold regions.

Application of Bitumen PG 64-22

The performance grade bitumen system uses standardized tests to evaluate the binder’s physical properties, which are closely related to the pavement’s performance under service temperatures. A major improvement in the Superpave system is that they must now be met under specific traffic conditions and pavement temperatures.

Factors Influencing the PG Grade of Asphalt

The Performance Grading system classifies asphalt binders based on performance under different conditions. Several factors affect the PG grade selection, including traffic loads, climate, pavement design, service life, and construction conditions.

Traffic Loads

Heavier traffic loads require higher PG bitumen grades to prevent rutting and deformation.

Climate Conditions

Extreme temperatures impact the binder’s performance. Hot climates need higher high-temperature grades, while cold climates require lower low-temperature grades.

Pavement Design

Pavement thickness, layer composition, and structure influence the penetration grade bitumen needed to withstand stresses.

Expected Service Life

Longer service life demands higher PG bitumen to ensure durability.

Construction Conditions

Construction practices, such as paving temperature and compaction, affect the binder’s final properties and performance.

Other Considerations

Material availability, costs, and local regulations may also impact PG bitumen selection.

Purchasing PG bitumen

At Kiapetro, we offer Performance Grade Bitumen for sale with competitive pricing and flexible payment options. Our PG bitumen meets international standards, providing excellent performance across a wide range of environmental and traffic conditions.

Kiapetro offers a full selection of PG bitumen grades, including PG 52-28, PG 64-10, PG 76-22, and others, tailored to suit specific project needs. Whether you’re looking for one-time purchases or recurring orders, we ensure timely delivery and high-quality products to meet your requirements.

FAQ

1. How to determine performance grade?

DSR Test (high-temperature), BBR Test (low-temperature)

2. How to calculate price performance?

Revenue variance = (Price difference) × (Units sold).

3. Can PG bitumen be used as waterproofing?

No, black bitumen is a great choice.