Method for Optimizing Key Evaluation Parameters of Recycled Asphalt: Based on Rheology and Chemistry

Abstract

This study proposes and validates a method to identify key parameters for evaluating recycled asphalt rejuvenation, aiming to simplify complex, multi-parameter testing into a practical and efficient assessment framework. Its core lies in using mathematical approaches to determine the relationships between rheological parameters and chemical composition parameters. While reducing the total number of parameters, this method selects key parameters with greater differences and independence, thereby enabling a comprehensive and accurate evaluation of the recycled asphalt condition. Based on correlation analysis, clustering analysis, regression analysis, and dimensionality reduction of both rheological and chemical composition parameters, this study ultimately selects G*/sinδ (a rheological parameter) and Saturates (a chemical parameter) as key evaluation parameters. This parameter combination not only simplifies the parameter system but also provides a relatively accurate prediction of the optimal regeneration agent content for recycled asphalt and its mixtures. Meanwhile, variations in these two asphalt parameters can, to some extent, reflect changes in mixture performance. The study provides preliminary evidence for the feasibility of this parameter-selection method for recycled asphalt and supports the validity of the selected key parameters. This method will promote high-quality and efficient recycling of aged asphalt, enhance the sustainability of recycled asphalt.