Simultaneous enhancement of the thermal oxygen and ultraviolet aging resistance of asphalt by incorporating antioxidant intercalated layered double hydroxide

This research aims to enhance the anti-thermal oxygen and anti-ultraviolet aging properties of asphalt binder simultaneously with antioxidant intercalated UV-shielding material. For this purpose, the antioxidant 1222 with excellent thermal oxygen resistance was used to modify UV-shielding material layered double hydroxides (LDHs) to synthesize antioxidant 1222 intercalated LDHs (LDHs-1222). The crystal phase, chemical structure and micro-morphology of LDHs-1222 were characterized. The physical properties, storage stability, rheological properties and aging resistance of LDHs-1222 modified asphalt before and after thermal oxygen and UV aging were also investigated. The results showed that CO32– in LDHs was substituted by phosphate group from antioxidant 1222, indicating the successful intercalation of antioxidant 1222. LDHs-1222 maintained the sheet structure and demonstrated a UV reflectivity of 70% and a radical scavenging efficiency of 84.53%, endowing it with desirable UV shielding property and free radical capture property. The incorporation of LDHs-1222 improved the storage stability of modified asphalt. LDHs-1222 modified asphalt exhibited lower complex modulus aging index, carbonyl index and sulfoxide index than LDHs, antioxidant 1222, and composite anti-ageing agent modified asphalts, indicating superior thermal oxygen ageing and UV aging resistance. 4% LDHs-1222 showed the most significant enhancement effect on anti-aging properties of asphalt.