ABSTRACT
Since 1981, most airports have used an internationally standardized method of airport pavement strength rating, which is based on simple pavement analysis models and categorical subgrades. With the broad implementation of mechanistic-empirical layered elastic pavement design methods, a mis-match between pavement thickness determination and pavement strength rating has evolved. To address this, a new system is being implemented that uses the same layered elastic model for strength rating as is used for pavement thickness determination in the United States and new subgrade categories, taken from French road design. Case studies on four Australian airports indicate how the new system may be implemented in countries that do not mandate prescriptive methods of pavement strength rating, rather using engineering judgment exercised by specialist engineers based on historical using aircraft, historical pavement performance and reverse engineering of existing pavement structures. The transition to the new system will create some challenges, mostly for those airports that do not know the basis of their current strength rating and can not locate historical existing pavement composition and subgrade bearing strength data. The cost of transition is estimated to be significant and is not justified because the new system provides no practical benefit to most airports in Australia.
