Surface-treated fish scale powder with silane coupling agent in asphalt for performance improvement: Conventional properties, rheology, and morphology

Abstract

There has been an increasing interest in using bio-waste materials to modify asphalt binders in recent years. Among the bio-waste materials, fish scale powder (FSP) has been widely studied in various industries, while the research in the asphalt industry is still limited. Thus, this work investigated the effect of silane coupling agent surface-treated fish scale powder (ST-FSP) on asphalt performance. The surface-treated fish scale powder modified asphalt (ST-FSMA) was then prepared with different mass rates (4%, 8%, 12%, and 16%). Fish scale powder modified asphalt (FSMA) and neat asphalt were also prepared as the control. It is found that the surface treatment with the silane coupling agent may further improve the modification effect of FSP on the penetration, softening point, viscosity, and rutting resistance of the asphalt binder. The master curves showed that ST-FSP could further increase the storage modulus and loss modulus of asphalt binder. Furthermore, the reduction in the ductility and compatibility of the asphalt binder due to the added FSP can be improved with the surface treatment. The influence of the surface treatment on the low- and intermediate-temperature behavior of the asphalt matrix is minimal. The mechanism analysis with Fourier transform infrared (FT-IR) spectroscopy confirmed the feasibility of grafting silane coupling agent onto FSP, and there is physical mixing between ST-FSP and asphalt. Fluorescence microscope (FM) and Scanning electron microscope (SEM) showed that the enhanced dispersibility and reduced agglomeration of FSP in the asphalt were observed from ST-FSMA. This work can provide insights into the utilization of fish scale waste as an innovative and sustainable biomaterial in the asphalt industry.