Influence of different anti-stripping agents on the rheological properties of asphalt binder at high temperature

Effects of different anti-stripping agents (ASAs) (M5000, M1 and LOF-6500) with various dosages (0.25%, 0.50% and 0.75% by weight of asphalt binder) on the rheological properties of asphalt binder before and after rolling thin film oven test (RTFO) at high temperature were investigated. The tested rheological properties included rotational viscosity, complex modulus (G∗), phase angle (δ), rutting resistance factor (G∗/sinδ), failure temperature, non-recoverable creep compliance (Jnr) and amplitude sweep. The results indicated that the rheological properties such as viscosity, G∗, δ, G∗/sinδ and failure temperature of ASA modified asphalt binders before aging depended on the ASA types and its dosages. After RTFO, all ASA modified asphalt binders showed the lower high temperature stability compared with blank sample, however, the high temperature performance grade maintained 64 °C unchanged. Besides, the Jnr susceptibility for stress level was weakened evidently by adding ASAs. As a result of the amplitude sweep test, compared with blank sample, all ASA modified asphalt binders after RTFO had the higher δ and G∗ values. Additionally, the introduction of ASAs could effectively improve the ability of asphalt binder to resist RTFO. Moreover, compared with M5000 and LOF-6500, the improvement degree of M1 was more apparent.