Preparation, Performance, and modification mechanism of high viscosity modified asphalt

A type of high viscosity modified asphalt (HVMA) with excellent performance was prepared by mixing a certain amount of SBS modifier, tackifying resin, stabilizer, and plasticizer into the base asphalt (BA) to meet the performance requirements of porous asphalt pavement. The influence of each modifier on the performance of composite modified asphalt was studied according to the basic physical performance test of asphalt, and the appropriate amount of each modifier was determined. The HVMA, BA, SBS/tackifying resin modified asphalt, and domestic high viscosity asphalt (HVA) were tested with a dynamic shear rheometer. The high temperature rheological properties of HVMA were evaluated by comparative analysis. The modification mechanism of HVMA was analyzed by Fourier transform infrared spectroscopy, scanning electron microscopy, and thermogravimetry/differential scanning calorimetry. Test results show that the 7% SBS modifier and 4% tackifying resin are the appropriate proportions. HVMA has excellent high temperature anti-rutting performance and anti-permanent deformation ability, which is not inferior to that of HVA. In the modification of HVMA, the modifier and BA are mainly physical blending; however, chemical reactions also occur. The modifier fully swells and evenly disperses in the asphalt, and the high temperature stability of the modified asphalt is effectively improved.