Effect of pretreated cow dung fiber on rheological and fatigue properties of asphalt binder

Abstract

Cow dung waste has caused severe environmental pollution and public health issues in China. In this study, the cow dung residues were used as a cheap renewable fiber to modify asphalt binder, providing a new solution for the proper disposal of cow dung waste. Three cow dung fibers with two lengths were prepared using different treatments, including original cow dung fiber (CDF), surface treatments of cow dung fiber (STCDF) and alkali treatments of cow dung fiber (ATCDF). The physicochemical properties of CDF, STCDF and ATCDF were analyzed by scanning electron microscope (SEM) and thermogravimetry (TG). The viscidity, rheological properties and fatigue characteristics of CDF modified asphalt binders (CDFMA) were evaluated using Brookfield viscometer and dynamic shear rheometer. The results showed that the rough surfaces of STCDF and ATCDF improved their thermal stability. STCDF and ATCDF enhanced the resistance to permanent deformation under high temperature conditions of modified asphalt binder. STCDF modified asphalt binders exhibited the best viscosity and rheological performance. The increase of fiber length was positively correlated with the high temperature deformation resistance of CDFMA. CDF, STCDF and ATCDF inhibited fatigue cracking of modified asphalt binders compared to base asphalt binders. ATCDF modified asphalt binders exhibited higher fatigue life and smaller crack under the same cyclic loading. The increase in fiber length had a slight improvement on the fatigue resistance of modified asphalt binders.

Double Effects of Oxidative Aging on Carbon Nanotube–Asphalt Nanocomposite Interfaces: Enhancement and Deterioration

“…Currently, researchers are aware of the multiscale nature of asphalt interfacial aging and have used a variety of techniques to explore the phenomenon, including molecular dynamics (MD) simulations, , Atomic Force Microscopy (AFM), Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR), and property evaluation. , However, these studies tend to summarize information from multiscales and rarely involve coupling between different scales . In addition, the dual effect of macroscopic properties and the multifactorial nature of aging make it difficult to clarify the pathways and mechanisms of asphalt property change.…”