High-Temperature Indirect Tensile Test to Assess Asphalt Rutting Performance in Airfield Mixes

The Federal Aviation Administration (FAA) P-401 specification for hot mix asphalt (HMA) includes mix acceptance performance criterion to limit rutting in airfield HMA mixes under high temperature and aircraft tire pressure. To achieve this goal, the specification requires mix acceptance performance criteria based on the asphalt pavement analyzer (APA) test. However, not all production laboratories have access to the specialized testing equipment required for APA testing. As a result, FAA is exploring additional tests that can serve as quality control (QC) indicators and rutting performance discriminators for asphalt mixes. One such test is the high-temperature indirect tensile test (HT-IDT), which aims to evaluate rutting performance in airfield asphalt mixes. To determine the effectiveness of this test, researchers evaluated multiple airfield P-401 mixes comparing HT-IDT strength values to field performance from accelerated pavement testing (APT) sections and results from APA testing. The results showed that a higher binder performance grade (PG) led to better performance results, as evidenced by the APT performance results. Moreover, the research found a strong correlation between HT-IDT strength values and APA and APT results. Therefore, the findings from this study suggest that the HT-IDT test could be an acceptable indicator of rutting performance in airfield mixes, as it effectively gauges rutting performance from accelerated pavement testing.