What property does the Performance Grade (PG) system evaluate in asphalt binders?

The Performance Grade (PG) system specifically evaluates the behavior of asphalt binders under varying temperature and loading conditions. This system provides a detailed understanding of how asphalt will perform in the field based on the climate and traffic it will experience. By considering both high and low temperature performance, the PG system identifies the binder's ability to resist deformation and cracking, which are critical factors in ensuring the longevity and durability of asphalt pavements.

The PG grading system categorizes asphalt binders based on their softening and hardening characteristics. It uses two key temperature points: the high temperature at which the binder remains stable and the low temperature at which it maintains flexibility. This helps engineers select the right binder for specific environmental conditions and traffic stresses, ensuring optimal performance over the lifespan of the pavement.

Understanding the PG system is essential for making informed decisions in the selection of asphalt binders for various projects, thus directly influencing the quality and performance of paved surfaces.