Performance evaluation of surface-organic grafting on the palygorskite nanofiber for the modification of asphalt

摘要

This paper aims to promote the application of nano-mineral materials in asphalt and improve the compatibility of modifiers with asphalt to produce high-performance and economical modified asphalt. In this paper, palygorskite (Pal) was organic grafted by gamma-aminopropyltriethoxysilane (ATPES) to obtain an organomodified palygorskite (A-Pal). Then A-Pal was adopted to modify asphalt by melt blending with different contents. The microstructure and elemental distribution of the modified asphalt were characterized to confirm the interface state of different components. The rheology, water stability and aging resistance of Pal and A-Pal in the asphalt were evaluated. The organic group was successfully grafted on the surface of Pal, and A-Pal had good compatibility with asphalt. Adding A-Pal could enhance the water stability, high-temperature stability and anti-rutting capacity of asphalt binder. The thermo-oxidative aging resistance of asphalt increased after TFOT and PAV aging under the shielding effect of A-Pal fibers. Considering high- and low-temperature performances, water stability, anti-aging performances and economic benefits, the optimal amount of A-Pal in asphalt was recommended from 4 to 6%. A-Pal has been proved to be an excellent and environmental-friendly asphalt modifier for the nanofiber effect. (C) 2020 Elsevier Ltd. All rights reserved.