Physical, rheological and micro characteristics of ARA/Nano-TiO 2 composite modified asphalt before and after short-term aging

This paper aims to investigate the composite application of nanomaterials and natural asphalt in order to enhance the road performance of asphalt pavement. The objective is to develop high-performance modified asphalt that improves the durability, reliability, and load resistance of asphalt roads while reducing resource waste and environmental pollution. The composite modified asphalt was prepared by adding different blends of Albanian natural rock asphalt (ARA) and 1% of nano titanium dioxide (Nano-TiO 2 ), and the basic properties and rheological properties of the asphalt before and after aging were tested by using basic performance tests and temperature scanning tests. Subsequently, the microscopic morphological characteristics of the asphalt were observed by scanning electron microscope and atomic force microscope, and the number of bee structures, the area share of bee structures, root mean square roughness R q, and arithmetic mean roughness R a were used as microscopic quantitative indexes. The results indicate that the complex modulus and rutting coefficient of ARA/ Nano-TiO 2 composite-modified asphalt increase with an increase in ARA dosage when the dosage of Nano-TiO 2 is 1%. The asphalt modified with Nano-TiO 2 composite blended with 15% ARA exhibits higher residual needle penetration, composite modulus ratio, rutting coefficient ratio and lower softening point increment compared to 70# asphalt. The bitumen modified with titanium dioxide nanocomposite blended with 15% ARA exhibits higher R q and R a and a more stable phase structure before and after aging. 15% of ARA/Nano-TiO 2 composite-modified asphalt has higher R q and R a before and after aging, and its phase structure is more stable. The results show that ARA/Nano-TiO 2 composite-modified asphalt has better high-temperature deformation resistance and aging resistance than 70# and that 15% ARA is recommended as the optimum amount of composite-modified asphalt.