Performance evaluation of asphalt mixture reinforced by lignin and ceramic fiber

A single-adding fiber technology only plays a role in improving one performance of asphalt mixture such as high temperature or low temperature or water damage performance. Although double-adding fiber-reinforced asphalt mixtures are expected to improve overall road performance, existing research still only focuses on the analysis of a single performance. In this study, two representative fibers including lignin fiber (LF) and ceramic fiber (CF) were selected including to investigate the role of double-adding fibers in asphalt mixtures. The effect of different fiber proportions on the overall road performance of stone matrix asphalt (SMA-13) mixtures was analyzed via wheel tracking tests, low temperature bending test, moisture susceptibility test and fatigue test, etc. The results revealed that the combined addition of LF and CF exhibited superior improvements in mechanical strength, anti-rutting performance, moisture susceptibility, and fatigue life as compared to that of using either fiber alone. Specifically, compared to that of SMA mixtures using LF, the SMA mixtures using both two fibers improved in 11% dynamic stability, 8.6% low-temperature bending stress, 2.1% moisture susceptibility and 20% fatigue life, respectively. And compared to that of SMA mixtures using CF, the mixtures using both two fibers increased in 11% low-temperature bending strain and 8% fatigue life, while improving slightly in dynamic stability, low-temperature bending stress, and moisture susceptibility respectively. Based on the results of efficiency coefficient method, the recommended ratio of LF to CF in the asphalt mixture is 1:2, providing a more balanced and comprehensive enhancement of road performances. This study provides a theoretical reference for the engineering application of improving the road performance of asphalt mixture through composite fiber blending, which can effectively enhance the service life of asphalt pavement.