Characterization and design of three-dimensional skeleton structure of asphalt mixture based on network science

The skeleton structure of asphalt mixture plays a crucial role in mitigating plastic deformation, preventing cracking, and resisting fatigue loading in pavement. While a well-designed skeleton structure can significantly enhance pavement quality and service life, the current design heavily relies on empirical methods and time-consuming repetitive experiments, lacking a precise pre-test framework. The objective of this study is to characterize and design the three-dimensional skeleton structure of asphalt mixture using the methodology of network science. Initially, we proposed a construction method for a weighted skeleton network based on the three-dimensional structure of asphalt mixtures with different gradings. Subsequently, we defined the triangular pyramid cycle (tp-cycle) comprising four nodes with full interconnections in all three dimensions. A multi-scale evaluation system was then established, encompassing metrics for nodes, tp-cycles, and the network, to assess the skeleton network's properties. Finally, we delved into the influence of mixture composition on the characteristics of the skeleton network, examining aspects at the particle-level, local-level, and system-level, and establishing correlations among them. The research findings have the potential to be utilized for predicting and optimizing the skeleton structure of asphalt mixture, offering valuable guidance and insights for mixture design and material performance enhancement.