Optimization of Aggregate Characteristic Parameters for Asphalt Binder—Aggregate System under Moisture Susceptibility Condition Based on Random Forest Analysis Model

Abstract

Water damage to asphalt pavements is a common occurrence that lowers the quality of service they can offer and causes several traffic problems. The loss of adhesion characteristics in the system of the asphalt binder and aggregate is the primary source of the problem of water damage in asphalt mixes. A number of things, including the impact of aggregate characteristics on asphalt binder—aggregate systems’ adhesion characteristics, have been proven. Through the use of random forest analysis, this study seeks to maximize the screening of aggregate characteristic factors. In this research, the morphology characterization, chemical composition, and phase composition of the five aggregates were first studied, and their relevant characteristic parameters were calculated. A method of engineering evaluation of the resistance of asphalt mixtures to water damage was used to assess the water susceptibility of the five asphalt binder—aggregate systems. Next, utilizing the fuzzy comprehensive evaluation analysis approach, a thorough study of the water susceptibility of the five asphalt binder—aggregate systems was conducted. Finally, sensitivity analysis of the aggregate characteristic parameters was carried out by a random forest analysis model, so as to achieve the optimal screening of the aggregate characteristic parameters. The results showed that, during sensitivity analysis of each parameter of aggregate properties using random forest analysis, the SiO2 content of the aggregate had the highest importance, and the roughness had the highest importance among the morphology characterizations. The water susceptibility of the asphalt binder—aggregate system could be expressed by the SiO2 content and roughness of the aggregate characteristic parameters.