Performance grade bitumen

Performance Grade (PG) bitumen is bitumen which is graded based on its performance at different temperatures. The Long-Term Pavement Performance(LTPP) has given certain algorithm to calculate the temperature of the pavement based on the temperature of the air above. From this, the highest and the lowest temperatures of the pavement is calculated and the bitumen that performs well in that temperature range is selected.

Penetration grading and viscosity grading are somewhat limited in their ability to fully characterize asphalt binder for use in Hot Mix Asphalt(HMA) pavement. Therefore, as part of the Superpave research effort new binder tests and specifications were developed to more accurately and fully characterize asphalt binders for use in HMA pavements. These tests and specifications are specifically designed to address HMA pavement performance parameters such as rutting, fatigue cracking and thermal cracking.