Full-component cascade utilization of waste cooking oil in asphalt materials

Abstract

Resources utilization of waste has become a global challenge with both environmental and economic issues. To realize the refinement recycling of waste cooking oil (WCO), a novel strategy was proposed in this work for the cascade utilization of different components of WCO in asphalt materials. Given the characteristics of each component in WCO, the analysis and verification were carried out for WCO as aged asphalt rejuvenators, warm mix asphalt additives, and thermal storage materials for asphalt thermoregulation. The results show that WCO components can be classified into three categories based on the nature of the fatty acid esters, namely waxy components, light oil components, and heavy oil components. Both light oils and heavy oils demonstrate great potential as rejuvenators of aged asphalt in terms of rheological properties and microscopic characteristics. Furthermore, it is worthy of expectation to select appropriate WCO components for performance recovery according to the actual aging degree of asphalt pavement. The waxy components of WCO can be applied for asphalt thermoregulation and warm mix asphalt additives after hydrolysis and ammonolysis respectively, which is conducive to improving the durability of roads, reducing the energy consumption and volatile organic compounds emissions during the construction process. The findings of the study contribute to the sustainable development of highway engineering and the recycling of waste resources.