Evaluation of anti-ageing performance of bitumen based on rheological and chemical characterisation

Improving the anti-ageing performance of bitumen plays a vital role in prolonging the service life of bituminous pavement. A bituminous additive for resisting all-weather ageing (BARAA), with excellent anti-ageing performance and fewer side effects, was developed in this study. The service life of bitumen can be doubled by using BARAA. The results show that the anti-ageing index and influence index can quantitatively evaluate the anti-ageing performance of anti-ageing additives. The BARAA was composed of amine antioxidant (1.89% by weight of base bitumen), Ni-containing antioxidant (3%) and hindered amine light stabilisers (0.7%). BARAA effectively delayed the deterioration of bitumen performance during ageing. The J _nr reduction of BARAA-modified bitumen caused by ageing was 17.7% of the base bitumen. At −12°C and −18°C, the S increase of BARAA-modified bitumen caused by ageing was about 35% of the base bitumen. The oxidation during ageing was inhibited. The growth of sulphoxide groups can be curbed by BARAA. After long-term ageng, the aromatic ring increase of BARAA-modified bitumen was 41.1% of the base bitumen. In addition, the increase of average molecular weight and functional group index of BARAA-modified bitumen caused by long-term ageing was 57% and 19.1% of the base bitumen, respectively.