Developing Representative Test Specimen Conditions for Rutting
Mechanical Test Methods of Airfield Pavements
Abstract
The Federal Aviation Administration (FAA) is considering implementation
of a balanced mix design method (BMD) for asphalt concrete (AC) of
airfield pavements in a future specification update. One of the key
elements towards implementing BMD, is setting adequate conditions for
laboratory mechanical testing that best simulate actual field
conditions. In this study, representative air void (AV) levels were
identified for laboratory mechanical testing by analyzing quality
control (QC) data of plant-mixed laboratory-compacted (PMLC) samples
along with in-place density measurements for multiple existing airfield
pavements. The laboratory compaction effort in the Superpave Gyratory
Compactor (SGC) required to reach the recommended AV levels were
evaluated for different specimen heights. The specimen height and AV
level were then experimentally verified with the Ideal Rutting test
(ASTM D8360-22) for these airfield mixtures. Based on analysis of field
density, laboratory compaction effort, and mechanical test data, it was
recommended to test 62 mm thick gyratory specimens at 7±0.5% AV
(directly molded) or at 5±0.5% AV (after cutting), which should help
capture the different aspects of the asphalt mixture’s resistance to
rutting in terms of aggregate skeleton and binder properties.