Rheological properties and microscopic characteristics of rejuvenated asphalt using different components from waste cooking oil

Abstract

The resource utilization of waste is of great significance to the sustainable development of society. Waste cooking oil (WCO) and reclaimed asphalt pavement (RAP), two typical wastes, have been plaguing the ecological environment for a long time. In this work, the different components of WCO were separated and employed separately as recycling agents for RAP to determine the suitability of various substances in WCO with RAP. The effects of different components of WCO on the rheological properties of aged asphalt were determined through dynamic shear rheometer (DSR) and bending beam rheometer (BBR). Meanwhile, the microscopic characteristics of rejuvenated asphalt using different WCO components were also discussed by atomic force microscope (AFM), Fourier transform infrared spectroscopy (FT-IR), and cluster analysis (CA). The experimental results indicate that all components of WCO have a significant effect on mitigating the brittleness of aged asphalt. However, some wax-like substances such as methyl palmitate in WCO are prone to solid-liquid phase transformation when the temperature decreases, which has a poor recovery effect on the fatigue and low-temperature performance of aged asphalt. It is suggested that waxy substances in WCO should be eliminated in advance to achieve efficient and stable regeneration of RAP when WCO is recycled as recycling agents for RAP. In terms of micro perspective, it is found that the lower the molecular weight of the WCO component is, the better its restoration effect on microscopic characteristics of aged asphalt is. The different effects of various substances in WCO on aged asphalt can be observed more intuitively after the classification of WCO components, which is instructive for the engineering application of efficient recovery of RAP using WCO.