Load Carrying-capacity of airport pavement
Classification, rating, evaluation
Aircraft manufacturers, airline operators, and airport managers all require information about airfield pavements at different airports to ensure that both the aircraft and the pavement can be utilised to the maximum extend without detrimental effects. Aircraft operations should not be rendered hazardous by pavement failure or uncomfortable due to excessive vibrations due to deformations. In order to avoid deterioration or excessive maintenance costs, airfield pavements must not be over stressed.
Effective pavement management requires a classification system; adequately representing the damaging effect of aircraft and the strength of the pavement. A classification system provides a method of limiting the loading on a pavement so as to allow the number of repetitions required to give an acceptable pavement life.

By international treaties among ICAO states, airport authorities are required to report airfield bearing strength in terms of the ACN/PCN classification system. According to the ICAO Aerodrome Design Manual the method is meant only for reporting of pavement strength data in the Aeronautical Information Publication (AIP). The ICAO documentation makes it very clear that it is not a design/evaluation method, nor does it contemplate the use of a specific method by the airport authority either for the design or evaluation of pavements. The ICAO documentation makes it very clear that the PCN is simply the ACN of the most damaging aircraft that can use the pavement on a regular basis (regular being defined by the operator). Although the Design Manual states that any method may be used to determine the load rating of the pavements, it is obvious that the use of layered elastic method in conjunction with calibrated failure criteria is preferred.

Pavers ® and the ACN/PCN system

Pavers ® enables the calculation of a PCN index according to the ICAO ACN-PCN load classification method, which is also used within NATO from 2001 on.

Whilst ICAO does not recommend specific software, use of a system such as Pavers brings many benefits. Pavers also supports the Dutch CROW Guideline on PCN Assignment (2013), The Ministry of Defense Standard on Pavement Strength Evaluation an Classification (2007), and is recommended as preferred NATO tool for PCN assignment (2005).

Non Destructive Testing (NDT) techniques are frequently used to determine the pavement's load-carrying capacity. The bearing strength of airfield pavements must be measured, analysed, evaluated and reported on a regular basis (at least every ten years) so that the operating weight of aircraft allowed to use the pavements can be controlled .... from heavy wide-bodied jets .... to relatively light aircraft.