Research for SEBS/PPA compound‐modified asphalt

In this study, polyphosphoric acid (PPA) was used to modify styrene–ethylene/butylene–styrene (SEBS)‐modified asphalt further and decrease the SEBS content in asphalt. Different structural analysis methods including morphology observation, infrared spectroscopy, thermal analysis were used to investigate the structural characteristics of asphalt modified by SEBS or PPA before and after short‐ or long‐term thermal ageing. The study shows the suitable addition of PPA can improve the major physical and rheological properties of SEBS‐modified (SM) asphalt and the improved properties became more obvious with further ageing. 0.8 wt % PPA can replace 2 wt % SEBS in the modification. Morphology observation showed PPA increased the incompatibility between SEBS and asphalt. Thermal analysis showed PPA changed the energy consumption and mass loss of SM asphalt greatly at elevated temperatures and led to the more complex structural characteristics.