Abstract: Nickel-ferrous slag fiber was used as modifier to produce road modified asphalt， and the performances of modified asphalt were evaluated by penetration， softening point and penetration index. The mechanism of modified asphalt by nickel-ferrous slag fiber was analyzed by means of scanning electron microscopy (SEM)， infrared spectroscopy(IR) and differential scanning calorimetry(DSC). The results showed that the high-temperature performance， low-temperature performance and temperature-sensitive performance of asphalt can be improved by nickel-ferrous slag fiber. The reason for the good effect of nickel-ferrous slag fiber on asphalt performance is to adjust the relative proportions of light components of asphalt composition under the foundation of physical blending， which leading the colloid type of the matrix asphalt to be more “sol-gel” type.

Key words: nickel-ferrous slag fiber, modified asphalt, mechanism