Impact of new high inflation pressure aircraft tyres on asphalt overlay interface debonding

Abstract

Aircraft tyre inflation pressures and wheel loads have increased over time and this trend is not expected to abate in the future. With increased tyre inflation pressures has come increased shear forces induced by braking aircraft. An increase in reports of interface debonding and delamination failures of asphalt surfaces on runways has followed in Australia, Japan and South Africa. Octahedral shear and normal stresses were calculated for extreme braking aircraft of various tyre inflation pressures and wheel loads. The historical increase in tyre inflation pressure of around 50 % was shown to have resulted in a moderate 10 % increase in the stress-strength ratio associated with the surface layer interface. The factor of safety associated with interface shear strength was shown to be negligible. New interface construction techniques or tack coat materials with increase adhesion are required to reduce the risk of further shear-related delamination of asphalt surfaces in high stress applications such as runways.