Exploration of Cracking-Related Performance-Based Specification Indexes for Airfield Asphalt Mixtures

Abstract

This study assessed the cracking performance of warm-mix asphalt (WMA) and reclaimed asphalt pavement (RAP) mixtures for airfield pavements and explored performance-based airfield asphalt mix specifications. Fundamental properties of these mixtures were investigated through performance-based laboratory tests such as complex modulus, semicircular bend (SCB), and direct tension cyclic fatigue (DTCF) tests. Performance prediction software was utilized to evaluate mixture performance during the design period. Based on the complex modulus and SCB tests results, it was found that organic additive and RAP tend to increase mixture susceptibility to fracture. Results of the DTCF test showed that fatigue indexes ranked mixtures in different ways, which emphasizes the importance of using performance prediction programs to investigate mixture fatigue performance. The results of performance prediction indicated that utilization of hybrid WMA additive and RAP would increase airfield pavement fatigue damage. The contradictory results of laboratory tests and pavement performance simulation showed that the airfield current asphalt pavement thickness design procedure lacks a usable model of fatigue cracking in its standard design program.