Performance evaluation of lignin-fibre reinforced asphalt mixture modified by anti-rutting agent

This paper aims to analyze the long-term road performance of anti-rutting agent (ARA) reinforced asphalt mixture, and reveal its road performance from the micro morphology and chemical perspective. ARA was used to modify the lignin fiber-reinforced SMA-13 asphalt mixture (LFSMA-13). The unaged, and the short and long-term aged specimens were used to test the road performance (high and low-temperature properties, water stability, and anti-cracking) of the LFSMA-13 and ARA modified LFSMA-13 (ALSMA-13). In addition, the micromorphology of the additives and asphalt mixture and the chemical property of asphalt in the mixture were analyzed using the scanning electron microscope (SEM) test and Fourier transform infrared (FTIR) test. The relationship between road performance and chemical property was also analyzed. The results showed that the performance of the ALSMA-13 was better with age than the LFSMA-13. The SEM images showed that the lignin fiber and the ARA could form a network structure in the SMA-13 mixtures. The FTIR test indicated that the ARA's amino group (–NH–) could chemically interact with the asphalt in SMA-13. The peak area of the carbonyl and sulfoxide chemical group increased, and the imino and methyl decreased with age. The results showed a good correlation between the FTIR parameters and road performance.