Abstract: The effect of adding crumb rubber (CR) and carbon nanotubes (CNTs) on the low-temperature properties of virgin asphalt was studied. Using the force-ductility test and the bending beam rheometer (BBR) test, the deformation resistance and rheological properties of asphalt samples at low temperatures were evaluated, respectively. Based on the result of BBR test, the creep functions of the Burgers model and the Zener model were used to fit the low-temperature creep characteristics of the asphalt samples. Furthermore, the differential scanning calorimetry (DSC) test and the attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIR) test were utilized to appraise the low-temperature stability and chemical properties of asphalt samples, respectively. The results showed that CR significantly improved the lowtemperature properties of virgin asphalt, while CNTs had little effect. Moreover, during the degradation of CR, aromatic and aliphatic components were released. In particular, the aliphatic components of CR-modified asphalt were much higher than those of virgin asphalt, which had a significant effect on improving the low-temperature properties of the asphalt. The DSC test results showed that CR enhanced the low-temperature stability of the asphalt, while the addition of CNTs presented a slightly negative effect.

Key words: Low-temperature properties, Crumb rubber (CR), Carbon nanotubes (CNTs), Creep characteristic, Asphalt components