Evaluation of hard petroleum asphalt's low-temperature performance and index optimisation based on the grey correlation model

Hard petroleum asphalt (HPA) has good application prospects because of its simple manufacturing process and excellent performance. However, according to previous studies, the performance of HPA at low temperatures cannot be well characterized by commonly used methods. The use of HPA in cold climates is severely constrained. In order to comprehensively evaluate the low-temperature performance of the material, this study used four different types of HPA as the research object, and used the bending beam rheological test ( BBR) to determine the basic rheological properties of the material. On this basis, after fitting and analysing the low-temperature creep compliance curve using the Burgers viscoelastic model, the asphalt was assigned a low-temperature viscoelastic assessment index. The glass transition temperature and sensitivity of HPA were investigated by differential scanning calorimetry (DSC). At the same time, the HPA assessment index at low temperatures was determined systematically by using grey correlation theory.