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Performance of New Materials for Aircraft Arrestor Beds

The design and the construction of currently employed aircraft arrestor beds require the presence of soft ground in which an aircraft in overrun decelerates as a result of drag forces acting on its landing gear. During this interaction, the wheels crush or displace the material until the airplane is completely stopped. The arresting systems are of special importance for those airports that do not have a safety area of the length required by international regulations. In the recent past, several materials with the capability for high energy absorption have been proposed, but most of them have been rejected so that some secondary effects—such as dust production during overrun, which leads to engine failure; short durability to environmental conditions; and limited mobility for rescue vehicles—can be reduced. This paper describes an experimental investigation performed on new materials by employing innovative testing protocols. Four materials of low density and low compressive strength—such as cellular mortar, cellular mortar with expanded polystyrene, and expanded clay pellets with bitumen and cement binder—have been considered. Quasi-static tests have been performed to define elastic–plastic transition points, and impact tests have been considered to assess the amount of energy that can be absorbed under the gears during the collapsing phase. Performance indicators of these new materials have been highlighted and compared with traditional indexes normally used for the characterization of existing arrestor beds.