Study on the performance of asphalt containing modified sulfur pellets

Sulfur can be added into asphalt to improve the high-temperature rut resistance of asphalt pavement. However, the H₂S is released during the mixing sulfur and asphalt at a high temperature. In this paper, modified sulfur pellets (MSP) were prepared by mixing sulfur, H₂S-inhibitors and filler to reduce the H₂S evolution. The results indicated that the free sulfur content in the mixture of asphalt and sulfur was higher than that in the mixture of asphalt and MSP, suggesting that more crosslinking sulfur which was beneficial to improve the performance of asphalt pavement produced in the mixture of asphalt and MSP. Environmental scanning electron microscopy (ESEM) micrographs showed that free sulfur particles in the mixture of asphalt and MSP were more homogeneously dispersed in asphalt. H₂S evolution was inhibited for a long time and even at a higher temperature after adding MSP in asphalt. The addition of MSP in asphalt resulted in the sharp increase in the dynamic stability from (1073±51) times/mm to (2410±214) times/mm for AC-20F bituminous mixture and from (1471±178) times/mm to (2530±165) times/mm for AC-20C bituminous mixture, respectively. The results of the study suggest that MSP can significantly reduce the H₂S evolution and strengthen the intensity of asphalt pavement.