Comparing Critical Pavement Responses in HMA and WMA (with RAP) Test Sections Measured Using Embedded Sensors under Accelerated Pavement Tests at NAPMRC

Use of environment-friendly warm mix asphalt (WMA) technologies with reclaimed asphalt pavement (RAP) materials in airfield asphalt concrete (AC) pavement construction is essential to reduce embodied carbon of airport pavements. However, the current Federal Aviation Administration (FAA) advisory circular for airfield construction neither provides a guidance on WMA technologies nor allows the use of RAP in AC surface mixes for airfield construction projects funded by the airport improvement program (AIP). Test Cycle 2 (TC2) at FAA’s National Airport Pavement and Materials Research Center (NAPMRC) studies the rutting and fatigue performances of three different WMA variants alongside one WMA variant with and without 20% RAP in the surface AC mix. Accordingly, six full-scale test lanes were constructed and subsequently trafficked with a 272.7 KN single moving wheel load under the influence of high temperature and tire pressure. Prior to traffic tests to failure, response tests were performed at different wheel loads to measure pavement responses. This paper summarizes the results from response tests, rutting performance of the WMA+RAP mix considering the strains at the bottom of the asphalt concrete layers and compressive stresses on top of the underlying layers. Rutting performance under accelerated pavement tests of WMA+RAP is compared with HMA. The RAP test sections exhibited comparable rutting performance to that of the control P-401 HMA test section.