Performance Grade (PG)

Performance Grade (PG) Bitumen is a more advanced classification of asphalt binder that is specifically engineered to deliver better performance in pavements under varying weather conditions, from extremely hot temperatures to very cold climates. This grading system was developed as part of the Superpave (Superior Performing Asphalt Pavements) system, which was established to introduce more scientifically based methods for selecting asphalt materials that meet specific regional climate and traffic conditions.

The PG system classifies bitumen based on its performance at different temperatures. The grades are denoted by two numbers, which represent the binder's maximum and minimum temperature limits. For example, a PG 64-22 bitumen is designed to perform adequately in regions where the pavement surface temperatures are as high as 64°C (147.2°F) during the hottest part of the year and as low as -22°C (-7.6°F) in the coldest season.

PG Bitumen is characterized by its ability to resist rutting and thermal cracking, fatigue damage, and low-temperature cracking, making it a crucial material for extending the lifespan of road surfaces under a wide range of environmental conditions and traffic loads. Its specifications focus on key properties such as viscosity, stiffness, rutting resistance at high temperatures, and flexibility at low temperatures.

The introduction of Performance Grade Bitumen allows for more precise specification and use of asphalt binders to match local climate variations and traffic patterns, leading to more durable and longer-lasting pavements. This tailored approach helps in reducing maintenance costs and improving road safety by ensuring better performance of road surfaces throughout the year.