Research on rheological properties of CNT-SBR modified asphalt

•The CNT can significantly improve the high temperature characteristics and anti-aging properties of SBR-modified asphalt.•The incorporation of CNT can improve the stress release rate of SBR-modified asphalt and improve the low temperature crack resistance.•The CNT incorporation can improve the fatigue damage resistance of SBR-modified asphalt and prolong fatigue life. For the sake of improving the high-temperature rutting resistance, storage stability, and fatigue endurance of SBR-modified asphalt. In this study, powdered carbon nanotubes (CNT) with a fineness of 1000 mesh were used to modify 4 % further SBR-modified asphalt. The physical properties and modification mechanism of CNT-SBR modified asphalt were studied by segregation test, temperature sweep, multiple stress creep test (MSCR), bending beam rheological test (BBR), linear scanning (LAS), and Fourier transform infrared spectroscopy (FTIR). Based on the test results, CNT incorporation can significantly enhance the rheological properties of SBR-modified asphalt, making it suitable for supporting higher traffic loads. Compared with SBR-modified asphalt, 1.5 %CNT-SBR modified asphalt significantly enhanced its high-temperature characteristics and anti-aging performance. −12 °C low-temperature stress relief rate raised by 12.6 %. Meanwhile, the 1.5 %CNT-SBR modified asphalt has excellent storage stability at high temperatures, the 70℃ dissociation rate is only 0.03, and fatigue life could be increased by 80.4 %. FTIR test showed that the reaction process of CNT, SBR, and neat asphalt belongs to physical blending. Moreover, FTIR test results showed that CNT and SBR could improve the anti-aging performance of neat asphalt. Careful consideration of CNT-SBR modified asphalt mechanical properties, when the SBR content is 4 %, the recommended CNT content is 1.5 % (1.5 %CNT-SBR).