PG Bitumen

• A.Crude Oil Refinement
• B.Modification Techniques
• C.Grading and Classification
• D. Quality Control and Testing

A. Crude Oil Refinement

The first step in the production of PG bitumen is crude oil refinement. Crude oil is a complex mixture of hydrocarbons that must be separated into different fractions in order to produce useful products. PG bitumen is produced from the heaviest fraction of crude oil, known as vacuum residue.

Crude oil is refined using a variety of processes, including distillation, cracking, and reforming. Distillation is a process that separates crude oil into different fractions based on their boiling points. The vacuum residue is the heaviest fraction of crude oil, and it is collected at the bottom of the distillation tower.

B. Modification Techniques

Once the vacuum residue has been collected, it can be modified to improve its performance characteristics. There are two main types of modification techniques: polymer modification and aging and temperature effects.

1. Polymer Modification: Polymer modification is a process that involves adding polymers to the vacuum residue. Polymers are long-chain molecules that can improve the performance of bitumen in a number of ways, including increasing its elasticity, reducing its viscosity, and improving its adhesion to aggregates.
2. Aging and Temperature Effects: Bitumen is a viscoelastic material, which means that its properties change depending on the temperature and the rate of loading. Aging is a process that causes bitumen to become more brittle and less viscous over time. This can be caused by exposure to sunlight, heat, and oxygen. Temperature also has a significant impact on the properties of bitumen. At high temperatures, bitumen becomes more fluid and less viscous. At low temperatures, bitumen becomes more brittle and more viscous.

C. Grading and Classification

PG bitumen is graded and classified based on its performance at different temperatures. The PG grading system uses two numbers to indicate the high-temperature performance grade (PG-HT) and the low-temperature performance grade (PG-LT).

The PG-HT is the highest temperature at which the bitumen can withstand rutting. The PG-LT is the lowest temperature at which the bitumen can withstand thermal cracking.

For example, a PG 58-28 bitumen has a PG-HT of 58 degrees Celsius and a PG-LT of -28 degrees Celsius. This means that this bitumen can withstand rutting at temperatures up to 58 degrees Celsius and thermal cracking at temperatures down to -28 degrees Celsius.

D. Quality Control and Testing

Once the PG bitumen has been produced, it is important to test its quality to ensure that it meets all of the required specifications. PG bitumen is typically tested for its viscosity, penetration, ductility, and softening point.

1. Viscosity and Performance Testing: Viscosity is a measure of the resistance of a fluid to flow. Penetration is a measure of the hardness or softness of a material. Ductility is a measure of how well a material can be elongated without breaking. The softening point is the temperature at which a material begins to soften. These tests are used to ensure that the PG bitumen has the desired performance characteristics for the intended application. For example, a PG bitumen that will be used in a hot climate will need to have a high softening point and a low viscosity.
2. Aging Susceptibility Tests: Aging susceptibility tests are used to measure how well the PG bitumen will resist aging. These tests are important because aging can cause bitumen to become more brittle and less viscous, which can lead to premature failure of the pavement. PG bitumen is a valuable product that is used in a wide variety of applications, including road construction, waterproofing, and roofing. By following the steps outlined above, refiners can produce a high-quality PG bitumen product that meets the needs of their customers.

Properties of Performance Grade Bitumen

PG bitumen has a number of unique properties that make it well-suited for a variety of applications. These properties include:

• Temperature resistance: PG bitumen is designed to perform well at a wide range of temperatures, from hot climates to cold climates. This is due to its unique formulation, which includes polymers that help to improve its elasticity and reduce its viscosity.
• Rutting resistance: PG bitumen is highly resistant to rutting, which is a common problem with traditional bitumen grades. This is due to its high softening point and its ability to maintain its viscosity at high temperatures.
• Thermal cracking resistance: PG bitumen is also highly resistant to thermal cracking, which can occur in cold climates. This is due to its low-temperature performance grade (PG-LT), which indicates the lowest temperature at which the bitumen can withstand thermal cracking.
• Thermal cracking resistance: PG bitumen is also highly resistant to thermal cracking, which can occur in cold climates. This is due to its low-temperature performance grade (PG-LT), which indicates the lowest temperature at which the bitumen can withstand thermal cracking.
• Longer service life: PG bitumen pavements have a longer service life than pavements made with traditional bitumen grades. This is due to the improved durability of PG bitumen.
• Reduced maintenance costs: PG bitumen pavements require less maintenance than pavements made with traditional bitumen grades. This is due to the longer service life of PG bitumen pavements and their resistance to rutting and thermal cracking.

Application of PG Bitumen

PG bitumen is a versatile material with a wide range of applications, including:

• Road Construction
• Asphalt Mix Design
• Benefits in Extreme Climates

Road Construction

• Hot mix asphalt (HMA): HMA is the most common type of asphalt pavement, and it is used for both new construction and pavement rehabilitation. PG bitumen can be used in HMA for a variety of traffic loading conditions and climatic conditions.
• Warm mix asphalt (WMA): WMA is a type of asphalt that is mixed at a lower temperature than HMA. This can reduce energy consumption and emissions during construction. PG bitumen can also be used in WMA.
• Open-graded asphalt (OGA): OGA is a type of asphalt pavement that contains a high percentage of air voids. This makes it more permeable to water and reduces the risk of hydroplaning. PG bitumen is often used in OGA to improve its durability and resistance to rutting.
• Asphalt emulsions: Asphalt emulsions are mixtures of asphalt and water that can be used for a variety of applications, such as chip seals, slurry seals, and tack coats. PG bitumen can also be used in asphalt emulsions.

Asphalt Mix Design

PG bitumen is used in asphalt mix design to ensure that the resulting asphalt mixture has the desired properties for the intended application. The selection of the appropriate PG bitumen grade is based on the following factors:

• Climatic conditions: The PG bitumen grade must be selected to withstand the expected temperature range and traffic loading conditions at the pavement site.
• Aggregate type and gradation: The PG bitumen grade must be compatible with the aggregate type and gradation.
• Asphalt pavement type: The PG bitumen grade must be selected for the specific asphalt pavement type, such as HMA, WMA, OGA, or asphalt emulsion.

Here are some specific examples of how PG bitumen is used in asphalt mix design:

• To improve resistance to rutting: PG bitumen grades with higher high-temperature performance grades (PG 64-22, PG 70-22, PG 76-10, etc.) and lower low-temperature performance grades (PG 58-28, PG 64-28, etc.) are typically used in asphalt mixes that are designed to resist rutting.
• To improve resistance to thermal cracking: PG bitumen grades with lower low-temperature performance grades (PG 58-28, PG 58-34, etc.) are typically used in asphalt mixes that are designed to resist thermal cracking.
• To improve durability in high-traffic areas: Polymer-modified PG bitumen grades are often used in asphalt mixes that are designed for high-traffic areas.
• To improve performance in cold climates: PG bitumen grades with higher low-temperature performance grades (PG 58-28, PG 58-34, etc.) are typically used in asphalt mixes that are designed for cold climates.

some other PG bitumen grade: PG 58-16, PG 64-10, PG 70-10, PG 76-10, PG 16-10, PG 76-16, PG 16-10, PG 82-22, PG 76-40, PG 70-40, PG 64-40, PG 52-40, PG 70-34, PG 64-34, PG 58-34, PG 52-34, PG 76-28, PG 70-28, PG 64-28, PG 58-28, PG 52-28, PG 76-22, PG 70-22, PG 64-22, PG 58-22, PG 52-22, PG 64-16)

Benefits in Extreme Climates

• Improved resistance to rutting in high-temperature climates: PG bitumen grades with higher high-temperature performance grades are more resistant to rutting, which is a common problem in hot climates.
• Reduced risk of thermal cracking in low-temperature climates: PG bitumen grades with lower low-temperature performance grades are less susceptible to thermal cracking, which is a common problem in cold climates.
• Increased pavement life: PG bitumen can help to extend the life of asphalt pavements in extreme climates by reducing the risk of rutting, thermal cracking, and other types of damage.
• Reduced maintenance costs: PG bitumen can help to reduce the long-term maintenance costs of asphalt pavements in extreme climates by increasing their durability and performance.

Advantage of PG Bitumen

• Improved performance: PG bitumen is designed to perform better in a wider range of temperature and traffic loading conditions. This can lead to longer pavement life and reduced maintenance costs.
• Reduced variability:  Performance-grade bitumen is produced to tighter specifications than traditional penetration-grade bitumen. This helps to reduce variability in the performance of asphalt pavements.
• Greater flexibility:  Performance-grade bitumen can be modified with polymers and other additives to improve its performance in specific applications. For example, polymer-modified bitumen can be used to improve the durability and resistance to rutting of asphalt pavements in high-traffic areas.

The Future of PG Bitumen in Construction

• Improved performance at extreme temperatures: Performance-grade bitumen grades are selected based on the expected temperature range of the pavement, which ensures that the bitumen will perform well in both hot and cold climates. This is especially important in regions with extreme temperature variations, where traditional bitumen grades may be more susceptible to rutting or thermal cracking.
• Reduced risk of rutting and thermal cracking: Performance-grade bitumen is formulated to resist rutting at high temperatures and thermal cracking at low temperatures. This helps to extend the lifespan of the pavement and reduce the need for repairs.
• Increased pavement durability: Performance-grade bitumen pavements are more durable than pavements made with traditional bitumen grades. This is because PG bitumen is better able to withstand the effects of traffic loading and environmental factors.
• Longer pavement service life: As a result of its improved performance and durability, PG bitumen pavements have a longer service life. This can lead to significant cost savings in terms of pavement maintenance and replacement.
• Reduced maintenance costs: Performance-grade bitumen pavements require less maintenance than pavements made with traditional bitumen grades. This is because they are less susceptible to rutting, thermal cracking, and other forms of damage.

addition to these benefits, PG bitumen is also a more sustainable material than traditional bitumen grades. This is because PG bitumen is produced using less energy and emits fewer greenhouse gases.

Here are some specific examples of how PG bitumen is being used to improve the construction industry:

• In the United States, Performance-grade bitumen is now required for all federal highway projects. This is a testament to the performance and durability benefits of PG bitumen.
• In Europe, Performance-grade bitumen is being used to construct more sustainable roads and bridges. For example, the A10 motorway in the Netherlands is one of the first roads in the world to be constructed using Performance-grade bitumen.
• In Asia, Performance-grade bitumen is being used to improve the quality of roads in rapidly developing countries. For example, China is investing heavily in Performance-grade bitumen to improve its road network.

Safety Tips for Performance Grade Bitumen

• Wear personal protective equipment (PPE): PPE is essential for protecting workers from the hazards of bitumen emulsion, including skin contact, inhalation of fumes, and burns. PPE should include gloves, goggles, a respirator, and long-sleeved clothing.
• Work in a well-ventilated area: Asphalt emulsion fumes can be harmful if inhaled, so it is important to work in a well-ventilated area when applying or handling bitumen emulsion.
• Avoid contact with the skin: Asphalt emulsion can be irritating to the skin, so it is important to avoid contact with the skin. If contact does occur, wash the affected area immediately with soap and water.
• Be careful with hot bitumen:  Asphalt emulsion can be heated to make it easier to apply. However, it is important to be careful with hot bitumen, as it can cause burns.
• Store and handle bitumen emulsion safely:  Asphalt emulsion should be stored in a cool, dry place away from direct sunlight and heat sources. It should also be handled carefully to avoid spills.

Additional Tips for Ensuring Worker Safety

• Train workers on the safe handling of bitumen emulsion: Workers should be trained on the hazards of Asphalt emulsion and how to safely handle it. This training should include information on PPE, ventilation, skin contact, hot bitumen, and storage and handling.
• Supervise workers closely: Workers should be closely supervised when working with Asphalt emulsion to ensure that they are following safety procedures.
• Have a spill response plan in place: In case of a spill, workers should know how to respond safely. This includes having the proper spill response equipment on hand and knowing how to use it.

Specification of PG Bitumen Types

	PG 46-34	PG 46-28	PG 52-28	PG 58-28	PG 58-22	PG 64-22	AASHTO Method
Flash Point, COC,°C	230	230	230	230	230	230	T 48
Flash Point, P-M, °C	NS	NS	NS	≥ 204	≥ 204	≥ 204	ASTM D93
Rotational Viscosity @ 135°C, Pa·s	3.00	3	3	3	3	3	T 316
Dynamic Shear @ Grade Temperature,°C	46	46	52	58	58	64	T 315
G*/sin @ 10 rad/sec, kPa	≥ 1.00	≥ 1.00	≥ 1.00	≥ 1.00	≥ 1.00	≥ 1.00	---
Mass Loss, %	≥ 1.00	≥ 1.00	≥ 1.00	≥ 1.00	≥ 1.00	≥ 1.00	T 240
Dynamic Shear @ Grade Temperature,°C	46	46	52	58	58	64	T 315
G*/sin @ 10 rad/sec, kPa	2.20	2.2	2.2	2.2	2.2	2.2	T 315
PAV Residue (Aging Temperature, °C)	90	90	90	100	100	100	R 28
Dynamic Shear @ Grade Temperature,°C	10	13	16	19	22	25	T 315
G*/sin @ 10 rad/sec, kPa	5000	5000	5000	5000	5000	5000	T 315
Creep Stiffness	-24	-18	-18	-18	-12	-12	---
S, Mpa	≤ 300	≤ 300	≤ 300	≤ 300	≤ 300	≤ 300	T 313
m-value	≥ 0.30	≥ 0.30	≥ 0.30	≥ 0.30	≥ 0.30	≥ 0.30	T 313

In Summary

Performance Grade Bitumen is a more advanced and accurate way to grade bitumen than traditional methods. It offers several benefits, including improved performance at high and low temperatures, reduced risk of pavement failures, and increased pavement durability.

As a result, Performance Grade Bitumen is becoming increasingly popular in a variety of applications, including HMA pavements, bridge deck overlays, crack sealing, asphalt emulsions, and waterproofing membranes.