Properties and mechanism of SBS/crumb rubber composite high viscosity modified asphalt

Previous studies have shown that traditional modified asphalt is difficult to meet the requirements of road quality at the requirements of permeable pavement quality at complex service environments. SBS/crumb rubber composite high viscosity modified asphalt(SBS/CR) was prepared by adding tackifying resin and other modifiers. Standard tube separation tests and rheological results showed that the SBS/CR has better high-temperature performance and storage stability. Atomic force microscopy (AFM) results concluded that the modifiers formed a stable network structure in asphalt system, restricting the free movement and diffusion of asphalt molecules. Asphalt molecules undergo phase changes in a small range, resulting in a "Bee structure" with a large number, small area, and uniform distribution, which improved its surface roughness. Fourier infrared spectroscopy (FTIR) and scanning electron microscope (SEM) analyses confirmed the modification mechanism includes both chemical reaction and physical modification. The tackifying resin was mainly combined with the asphalt binder in the form of physical fusion. Compared with matrix asphalt, the internal structure of the SBS/CR was more stable, the heat absorption area became smaller, and the thermal stability was improved.