Challenges for Australian flexible airport pavements

Since the end of direct Commonwealth government management of Australian airports in the 1990s, there has been no coordinated up-keep of airport pavement technology and practice in this country. In contrast, aircraft technology has advanced significantly. To address significant risks, a number of construction contractors have introduced new products and methods. However, the risk-averse nature of the airport industry has sometimes resulted in good solutions being resisted. A number of challenges relating to flexible aircraft pavements have resulted, including aircraft with higher tyre pressure and wheel load combination than previously experienced and an associated inability to ‘prove’ the upper fine crushed rock base layers during construction. Also, a general reduction in bitumen reliability has resulted in the increased use of polymer modified bitumen for asphalt production, but these products are not readily available in regional areas. Moreover, airport asphalt was routinely rejuvenated to extend the period between resurfacing, but increased concern for the impact of surface treatments on skid resistance has resulted in some designers no longer recommending such maintenance. A reduction in the number of specialised airport pavement engineers has meant that expertise, particularly in spray seal design for airports, has become limited. The reduction in expertise has also seen the development of new methods for expedient airport pavement rehabilitation be substantially left to construction contractors. A collaborative, airport-industry-wide initiative is essential to addressing these challenges in the future.