Closing the Fine Crushed Rock Proof Rolling Gap in Airport Pavement Construction

Abstract

Proof rolling is a critical element of constructing airport pavements. This is particularly important in Australia, where flexible airport pavements generally comprise thick fine crushed rock layers with a relatively thin asphalt surfacing, and rigid airport pavements still make use of fine crushed rock sub-base materials. Traditionally, purpose-built proof rollers were capable of inducing stresses in the crush rock layers that exceeded those induced by commercial aircraft trafficking the surface of the pavement. However, as proof rolling tyre pressures have been decreased and aircraft wheel loads and tyre pressures have increased, a gap between the proof rolling capacity and the aircraft-induced stress has developed, mainly affecting the upper base layers of flexible airport pavements. This research developed and compared approaches for closing the gap, including the design of a replacement proof rolling fleet, the incorporation of more expensive bound base course layers, and retrofitting second-grade aircraft tyres to the existing proof rollers. The conclusions allow the Australian airport pavement construction industry to close the fine crushed rock proof rolling gap for more reliable airport pavement construction.