Effects of Different Nanofibers on Self-Healing Properties of Composite Modified Emulsified Asphalt

摘要

To improve the self-healing performance of styrene-butadiene-styrene/multiwalled carbon nanotube composite modified emulsified asphalt (SMEA), three representative types of nanofibers were used to reinforce SMEA, and their effects on self-healing properties of SMEA were discussed by the developed self-healing evaluation methods. Test results indicate that basalt (BS) nanofiber without shape memory performance not only decreases the ductility and low-temperature cracking resistance of evaporation residue of SMEA after self-healing but also lowers the self-healing performance of SMEA. On the contrary, polyethylene terephthalate (PET) nanofiber and polytri-methylene terephthalate (FIT) nanofiber improve the ductility and low-temperature cracking resistance of SMEA. Further, PTT nanofiber with a stronger shape memory property more obviously increases the self-healing performance of SMEA than PET nanofiber. Additionally, the self-healing index of dissipated energy ratio (HI~3) before and after self-healing is more suitable to characterize the self-healing performance of nanofiber-reinforced SMEA. Finally, PTT nanofiber-reinforced SMEA shows satisfactory repeated self-healing performance. PTT nanofiber at the content of 0.35% is proposed to reinforce SMEA, developing more durable modified emulsified asphalt for the maintenance and repair of asphalt pavement.