High temperature rheological properties of surface pretreated PVA fiber modified asphalt

Abstract

In order to improve the compatibility of polyvinyl alcohol (PVA) fiber and asphalt in application of asphalt pavement, the surface of PVA fiber is pretreated with KH-570 silane coupling agent. The tests such as contact angle, rotational viscosity, temperature scanning, multiple stress creep and recovery (MSCR) and the linear amplitude sweep (LAS) are conducted to study the compatibility and high temperature rheological properties of original PVA fiber (T) and surface treated PVA fiber (ST) modified asphalts with different contents, so as to evaluate the effect of surface modification process on the rheological properties of PVA fiber modified asphalt. The results show that the surface treatment process improves the compatibility of asphalt and PVA fiber. Compared with T, ST has better viscosity increasing effect, rutting resistance, and permanent deformation resistance at the same content, and can slightly improve the fatigue resistance of asphalt at the lower strain level. However, T and ST have no obvious improvement on creep deformation ability and fatigue life of asphalt at high stress level under repeated load. The surface pretreatment process can effectively improve the storage stability, viscosity and high temperature deformation resistance of the binder and the results provide reference for the preparation and application of PVA fiber modified asphalt.