Investigation into the variation in airfield pavement strength rating calculation

Abstract

The Pavement Classification Number (PCN) was an international method developed by the International Civil Aviation Organization (ICAO) to report runway, taxiway as well as apron pavement strength. In the past, the great variation in calculated PCN values obtained through available internationally recognised methods for PCN calculation, allowed pavement engineers to target a specific PCN to the potential detriment of the airfield pavement and its safe operation. Recently, in June 2020, the ACN-PCN system was replaced by the new ACR-PCR (Aircraft Classification Rating ‒ Pavement Classification Rating) system. During this study a series of PCN calculations were performed for a range of typical airport pavement structures with different internationally recognised PCN calculation approaches. The process was repeated using the new PCR approach with the currently available calculation approaches. The variation in PCN was compared to the variation in PCR to confirm if the new rating system results in reduced variation. The analysis confirmed a reduced variation in calculated ratings for flexible pavements, but not for rigid pavements.