Review of Recent Research on Using Gyratory Compaction to Design Hot Mix Asphalt for Airfield Pavements

This document is a critical review of three recent reports detailing research on the appropriate level of design gyrations to use when preparing hot mix asphalt (HMA) mix designs for airfield pavements using the gyratory compactor. Research performed at the U.S. Army Corp of Engineers Engineering Research and Development Center (ERDC) recommended using 70 gyrations when designing HMA for airfield pavements using the gyratory compactor. The results from research using a similar approach, sponsored by the Federal Aviation Administration (FAA) and performed by SRA International, Inc. (SRA) and several other contractors, concurred that 70 gyrations was an appropriate compaction level. This research also found that HMA designed using 75-blow Marshall compaction and 70 gyrations exhibited similar levels of rut resistance and fatigue resistance when evaluated in laboratory tests. A third study, Airfield Asphalt Pavement Technology Program (AAPTP) Project 04-03, also examined the issue of using gyratory compaction to design HMA for airfield pavements. In this project, it was recommended that design gyrations should increase with increasing tire pressure. For example, the AAPTP 04-03 report recommended that, for HMA subject to aircraft tire pressures in excess of 200 lb/in2, 80 gyrations should be used in preparing specimens during the mix design process. Although the concept of linking design gyrations to aircraft tire pressure has merit, the performance test used in developing these recommendations was not calibrated to actual pavement performance. Therefore, it is recommended that 70 gyrations be used in preparing mix designs for HMA for airfield pavements, in accordance with the ERDC and FAA/SRA reports.

DOT/FAA/TC-13/48
Author: Donald W. Christensen, Jr., PhD