Research on the Characteristics of Asphalt Mixture Gradation Curve Based on Weibull Distribution

Gradation design is the critical procedure for asphalt mixture design, a proper mineral gradation could provide excellent volumetric and mechanical properties for asphalt mixture. Most previous studies were focused on the effect of single particle content on the properties of mixture, which could result in uncontrolled and unpredictable mixture performances, and the comprehensive characterization of the entire gradation curve needs to be extensively explored. Therefore, this research proposed a two-parameter Weibull distribution model to describe the aggregate gradation, and the applicability of the Weibull model and the fractal model was compared for different gradations. Besides, the influence of the gradation characteristics parameters on the volumetric indexes of mixture was evaluated by 332 groups of field and experimental gradation design. Finally, the factors influencing the uniaxial compressive strength (UCS) of the porous asphalt concrete were evaluated by the grey correlation analysis, and a multiple regression model for the UCS of mixture was developed. The results indicated that there were linear correlations between gradation characteristics parameters and mixture volumetric indexes, and it was feasible to predict the UCS of asphalt mixture by known material parameters.