Modification and enhancing effect of SPUA material on asphalt binder: A study of viscoelastic properties and microstructure characterization

In order to significantly improve the viscoelasticity and durability of asphalt materials, Spray polyurea (SPUA) resin modified materials with different particle sizes were obtained by low-temperature fine grinding process in this study, and the corresponding SPUA modified asphalt was prepared. The basic properties of resin modified asphalt were compared and analyzed. The influence of SPUA resin modification materials on the apparent viscosity of asphalt was analyzed. Through dynamic shear rheometer (DSR) and bending beam rheometer (BBR) test, the effect of SPUA resin material on rheological properties of asphalt was systematically investigated. Furthermore, the modifier and asphalt binder were characterized by scanning electron microscopy (SEM) and X-ray energy dispersive spectroscopy (EDS). Results show that decreasing the particle size or increasing the dosage of the SPUA modifier could improve the softening point and apparent viscosity and reduce the ductility, which indicate SPUA modifier could improve the high temperature shear resistance and elastic recovery performance of asphalt binder. The SPUA modifier with smaller particle size has better high temperature rheological modification effect and less negative effect on low temperature performance deterioration. Although part of the functional spherical structure was damaged, the 0.075 mm SPUA modifier could closely interact with the base asphalt perfectly. This study would provide the scientific references for the application of Spray polyurea resin materials in the field of asphalt pavement materials.