28 Apr 2020

PUBLICATION NOTICE: Feasibility Investigation of Inductive Heating of Asphalt Repair Materials

Abstract: Airfield pavement repairs conducted as part of rapid airfield damage recovery (RADR) activities must utilize suitable materials to reduce the need for subsequent repairs in order to maintain an operable pavement surface. For asphalt concrete pavements, hot mix asphalt (HMA) is typically used, but this requires a fairly large operation and is less practical for small repairs (e.g., small munitions damage, potholes). Instead, cold mix asphalt (CMA) is typically used for small repairs; however, its performance under aircraft loads is generally unacceptable.  The objective of this project was to investigate the feasibility of rapidly heating small-repair quantities (e.g., 5 gal buckets) of asphalt mix to hot mix temperatures in a matter of minutes. This objective was met using 15% steel aggregate by volume to produce an inductive HMA (iHMA) that could be heated from ambient to 320°F in approximately 5 min. This technology was demonstrated at full scale with a prototype field induction heater; iHMA patch repairs were subjected to simulated F-15E traffic and exhibited comparable rutting resistance to conventional HMA, which was considerably improved relative to CMA. Overall, iHMA was found to be a feasible repair material and should be considered for additional refinement and eventual implementation.