Comparative Performance of Different Warm Mix Asphalt Technologies under the Influence of High Aircraft Tire Pressure and Temperature

Abstract

Warm mix asphalt (WMA) technologies allow the production and placement of asphalt concrete materials at a lower temperature than the traditional hot mix asphalt (HMA). These materials simultaneously reduce the production fuel costs, increase the available hauling distance, lengthen the paving season, are eco-friendly, and ensure safer working conditions. Airport authorities can use such materials for construction applications to minimize the downtime and user-delay costs. However, the existing Federal Aviation Administration (FAA) construction specifications do not provide guidance on the implementation of such technologies, especially under the conditions created by aircraft with high tire pressure. To this end, the FAA National Airport Pavement and Materials Research Center (NAPMRC) conducted accelerated pavement tests as part of Test Cycle 1 (TC-1) to study the application potential of WMA (using chemical additive) on airport pavements. TC-1 results showed WMA performance was comparable to P-401 HMA performance in rutting. Test Cycle 2 (TC-2) study investigated the rutting performance of chemical, organic, and hybrid additive-based warm mixes alongside an FAA specification P-401 HMA counterpart. Four different test lanes were constructed accordingly in the outdoor area of NAPMRC, each encompassing three different test sections. Using the sixth-generation airport heavy vehicle simulator (HVS-A), sections on the north side of the test lanes were trafficked with 61.3 kips (272.7 kN) moving wheel load at a controlled temperature of 120°F (48.9°C). The chemical additive-based warm mix appeared to exhibit comparable performance to the HMA. A laboratory characterization effort also seemed to corroborate the rutting observations from traffic tests.