Effect and mechanism of calcium carbonate whisker on asphalt binder

Calcium carbonate whisker (CCW) has been widely used for its excellent mechanical and physical properties as well as low manufacturing cost and simple process. In this study, CCW was added into asphalt binder to produce modified asphalt. The morphological characteristics, thermal performance and rheological properties of CCW and the modified asphalts were studied with various experimental methods. In order to enhance the compatibility of asphalt and CCW, the silane coupling agent (2 wt%, KH-570) was used to treat the surface of CCW. Results show that the addition of CCW can improve the softening point of asphalt and decrease its penetration and ductility. In addition, the rutting resistance of the modified asphalt has been increased to some extent. As the presence of silane coupling agent, the interaction between asphalt and CCW and the storage stability of CCW modified asphalt were slightly increased.