Development of rational ACN/PCN system

Abstract

The Aircraft Classification Number/Pavement Classification Number (ACN/PCN) system is the worldwide official airfield pavement rating method. It relies on the concept of aircraft equivalency to a single-wheel load on a given pavement structure. For flexible pavements, this underlying pavement is implicitly determined by the semi-empirical California Bearing Ratio (CBR) procedure. However, new pavement design methods have emerged, based on a rational approach and making an extensive use of the Multi-Layer Linear Elastic Analysis (ML2EA). These methods are now widely used for pavement design, hence raising the issue of consistency with the ACN/PCN system. The International Civil Aviation Organization (ICAO) initiated the work aimed at renewing the ACN/PCN system by taking advantage of these new methods, thus overcoming the well-known drawbacks of the CBR procedure. This paper describes the development and the fine-tuning of this renewed ACN/PCN system, which is to become the standard in the upcoming years.