Investigating the interaction mechanism and effect of different calcium sulfate whiskers on performance of asphalt binder

Abstract

Three kinds of calcium sulfate whisker (CSW) and two types of asphalt binders were used to prepare the modification asphalt by mechanical stirring. The influence of the types and contents of CSW on the high temperature performance, deformation resistance property, temperature susceptibility performance, viscosity-temperature characteristic, rheological property and low temperature performance of asphalt binder were respectively analyzed by softening point test, ductility test, cone penetration test, Brookfield rotational viscosity test, dynamic shear rheometer (DSR) and bending beam rheometer (BBR). In addition, the interaction mechanism of CSW with asphalt binder was investigated by the Attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIR), X-ray diffraction (XRD) analyzer and Scanning electron microscope (SEM). The results indicate that three CSWs can significantly improve the high temperature performance, rheological property and deformation resistance property of two asphalt binders, but will weaken their temperature susceptibility performance, viscosity-temperature characteristic and low temperature performance to some extent when CSWs contents range from 7 wt% to 11 wt%. The effect of CSWs on the performances of asphalt binder is related to the types of CSW and the kinds of base asphalt, respectively. The results of ATR-FTIR, XRD and SEM tests indicate that the interaction between CSWs and asphalt binder is physical adsorption and interleaving process.