Performance grade bitumen, (designated by the letters PG), is the most recent standard of bitumen. It has been established to define the performance of bitumen according to a complete set of specifications combining climate, traffic, and ageing. The binder is chosen according to the climate where the pavement will be installed, taking into account the highest and lowest temperatures. Tests are carried out in order to respond to specific types of pavement degradation such as rutting, fatigue cracking, and cracking at low temperature. Traffic is taken into account by adjusting the class towards a more rigid material for high traffic volume or heavy loadings. Performance Grade Bitumen is defined by AASHTO M320-05 standards, three tests are carried out:

– The Dynamic Shear Rheometer (DSR) to characterize the bitumen at high and intermediate pavement temperatures

– The Bending Beam Rheometer (BBR) to measure the properties at expected minimum pavement temperatures

– The direct tension tester (DTT) to measure the stiffness and stress relaxation properties of asphalt binders at low temperature