Performance Grade (PG) Bitumen is bitumen is graded based on its performance indicated in different temperatures. In Super pave grading system, according to their performance in extreme hot and cold temperatures, binders are classified and are called as performance grade (PG) bitumen. The main goal of grading asphalt binder using the PG system and selecting it is to make sure that the binder has the appropriate properties needed for environmental situation it’s going to be used in. PG asphalt binders are selected to suit the expected climatic conditions as well as volume adjustments and traffic speed. Therefore, the PG system uses a set of tests to measure physical properties of the binder which can be directly related to field performance in the paving situation.
The Long-Term Pavement Performance (LTPP) has given a controlled algorithm to calculate and derive the temperature of the pavement based on the temperature of the air above. From this, the range of the temperatures of the pavement are indicated and the bitumen that performs the best in the defined conditions is selected. Penetration grading and viscosity grading face some limitations in their ability to completely characterize asphalt binder for use in Hot Mix Asphalt (HMA) pavement. Therefore, as part of the Superpave research, new specifications and binder tests were developed to more accurately and comprehensively to determine the characteristics of asphalt binders to be used in HMA pavements. These tests and specifications are mostly designed to address HMA pavement performance parameters such as fatigue cracking, rutting ,and thermal cracking. Superpave performance Grade (PG) Bitumen is developed on the idea that an HMA asphalt binder’s properties should be according to the conditions under which it is applied.

The PG grading system is defined by two numbers, representing the pavement temperatures. The first number (ex: PG 64-XX) represents the highest pavement temperature in Celsius, while the second number (ex: PG XX-22) represents the lowest. Note that these numbers are pavement temperatures, not the air temperatures (these pavement temperatures are derived from air temperatures using an algorithm included in the LTPP Bind program). The high temperature is related to the effects of rutting and the low temperature relates to cold results such as fatigue cracking.