Influence analysis of performance of semi-flexible pavement based on aggregate distribution characteristics of matrix skeleton

In this study, five different gradation types of semi-flexible pavement (SFP) were formed by changing the gradation and porosity of the matrix skeleton. The porosity and its distribution of the matrix skeleton were characterized by two aggregate distribution characteristics indexes: aggregate total area index (IA) and aggregate average area index (IAA). The specific influence relationship between independent and related changes of IA and IAA on the performance of SFP was investigated, and the influence of IA and IAA on the same performance and different performance of SFP was compared. The results showed that the effect of IA on each performance of SFP with single-particle size gradation was more significant. In contrast, the impact of IAA on each performance of SFP with continuous gradation was much more significant than its effect on single-particle size gradation. When IA and IAA were analyzed independently, the influence of IAA on the properties of SFP was much more significant than that of IA. When IA and IAA were analyzed correlatively, the properties of SFP were more influenced by IA. When IA and IAA are changed associated, the influence degree of each performance of SFP from large to small is: maximum bending strain > bending strain energy > dynamic stability = Dynamic modulus (54 °C) = Dynamic modulus (21.1 °C) > TSR > phase angle (54 °C) > residual stability > phase angle (21.1 °C). To obtain SFP with suitable high-temperature stability, low-temperature stability, and water stability simultaneously, it is suggested that the IA of the designed matrix skeleton is between 72 % and 78 %, and IAA is between 1 % and 1.8 %.