Laboratory Evaluation of Rheological Properties of Asphalt Binder Modified by Nano‐TiO<sub>2</sub>/CaCO<sub>3</sub>
Zhang Liming, Xuekai Gao, Wensheng Wang, Hua Wang, Kunkun Zheng
Abstract
Nanomaterials have a great potential for enhancing the performance of base asphalt binder. This study aims to promote the application of nano‐TiO 2 /CaCO 3 in bitumen and presents a study on rheological properties for TiO 2 /CaCO 3 nanoparticle‐bitumen. In this study, a series of laboratory experiments have been performed for bitumen with different nano‐TiO 2 /CaCO 3 dosages. Nano‐TiO 2 /CaCO 3 ‐modified bitumen with optimum dosage was prepared for viscosity, dynamic shear rheometer (DSR), and beam bending rheometer (BBR) for assessing temperature sensitivity of bitumen, and the low‐medium‐high‐temperature performances were analyzed for TiO 2 /CaCO 3 nanoparticle‐bitumen as well. Results show that bituminous mechanical properties were enhanced by TiO 2 /CaCO 3 , and based on the overall desirability analysis of various conventional tests, the reasonable dosage of nano‐TiO 2 /CaCO 3 was recommended as 5% by weight of base bitumen. Adding nano‐TiO 2 /CaCO 3 was beneficial to improve the viscosity and reduce the temperature sensitivity of bitumen. The capacities of bituminous rutting resistance as well as medium‐temperature fatigue resistance were enhanced by the addition of nano‐TiO 2 /CaCO 3 . However, BBR test shows that bituminous anticracking is reduced slightly. On this basis, the Burgers model is selected for clarifying the decrease in anticracking performance; that is, nano‐TiO 2 /CaCO 3 increased the stiffness modulus while increasing the viscosity of bitumen.