Preparation and performance of oxidized crumb rubber (OCR)/nano-SiO2 composite-modified asphalt

[Display omitted] •Optimum preparation conditions for OCR/nano-SiO2 modified asphalt were studied.•The oxidation treatment changed the microscopic characteristics of crumb rubber.•OCR improved the high-temperature properties and storage stability of the asphalt.•The swelling of the OCR in asphalt was more sufficient than that of untreated CR. The purpose of this study was to improve the problems of inadequate storage stability and insufficient high-temperature rutting resistance of crumb rubber-modified asphalt (CRMA) by adding nano-SiO2 and pre-oxidizing crumb rubber (CR). Hydrogen peroxide (H2O2) and sodium hypochlorite (NaClO) were used to oxidize the CR. The results indicated that the CR obtained the optimum oxidization effect in 30 mL H2O2 solution at 80 °C for 2 h under the catalysis of ferrous sulfate (FeSO4). Besides, oxidation treatment of the CR significantly improved the storage stability and high-temperature properties of the CR/nano-SiO2 composite-modified asphalt.