Performance of Grooved Warm-Mix Asphalt Pavement Surfaces under Heavy Aircraft Load and High Tire Pressure

This paper presents an evaluation of the performance of grooved warm-mix asphalt (WMA) under heavy aircraft loading compared with that of grooved hot-mix asphalt (HMA). Runway surface grooving is often required to provide high skid resistance for aircraft braking, particularly in wet conditions where hydroplaning must be minimized. An area of potential concern with the use of WMA on the surface of airfield runway pavements is the material response to surface grooving. If the asphalt binder in WMA is softer than that of comparable HMA because of reduced binder aging during production and placement, the WMA mixture may be more likely to experience groove closure or collapse. This condition could result in hydroplaning issues because of the reduction in water discharge and also in chipping of aggregate from the groove edges, which could increase the potential for foreign object damage. A full-scale experiment was designed to evaluate two pavement curing conditions and three WMA mixtures. Traffic was applied to the pavements with an F-15 load cart, and testing occurred during the summer of 2013. The performance of WMA, measured as the percentage of groove closure, was compared with that of comparative HMA. It was concluded that WMA could perform as well as HMA under different pavement curing conditions. This result indicates that WMA runway surface pavement that is properly cured before grooving should not exhibit groove closure under normal aircraft traffic conditions.