Composite nano-TiO2/CaCO3 was prepared by coating a layer of nano-titanium dioxide on the surface of calcium carbonate as asphalt modifier. In order to objectively evaluate the modification effect of the nanoparticles on asphalt, the optimum content of composite nano-TiO2/CaCO3 and the preparation technology of modified asphalt were determined on the basis of the road performance of asphalt before and after aging and grey relational analysis method. At the same time, the road properties and rheological properties of composite nano-TiO2/CaCO3 modified asphalt at different temperatures were studied by Dynamic Shear Rheological test (DSR), Beam Bending Rheological Test (BBR) and Rotational Viscosity test (RV).The results show that the effect of technological conditions on the properties of composite nano-TiO2/CaCO3 modified asphalt is as follows: reaction temperature > shear rate > shear time. The optimum content of composite nano-TiO2/CaCO3 is 5% and its preparation process is that the reaction temperature 170 ℃, the shear rate 5000 r / min，and the shear time 40 min. The addition of composite nano-TiO2/CaCO3 changed the viscoelastic ratio of asphalt, significantly improved its high temperature stability and anti-aging performance. Although its low-temperature stress relaxation ability is reduced, it still has good application value. Meanwhile, the viscosity temperature index (VTS) indicates that nano-TiO2/CaCO3 reduces the temperature sensitivity of the asphalt, also has good construction performance.

CICTP