Study on the applicability of asphalt concrete skeleton in the semi-flexible pavement

Abstract

This study formed the semi-flexible pavement (SFP) based on five different gradation types of asphalt concrete skeleton. The basic properties of these five kinds of asphalt concrete skeletons and the volume stability, mesostructure characteristics, high-temperature performance, low-temperature performance, water stability, and strength characteristics of the formed SFP were tested and evaluated. We observed that the continuous gradation asphalt concrete skeleton with the minor air void and the most dispersed air void has better volume stability and high-temperature performance. SFP formed by single-particle size gradation asphalt concrete skeleton has better high-temperature and water stability. The low-temperature crack resistance of SFP with continuous gradation asphalt concrete skeleton is better than other SFP. The higher the cement content and the more concentrated the distribution, the more stable the strength and strength composition of SFP at different temperatures. The high-temperature stability and low-temperature crack resistance of SFP are the most affected by the average area of single aggregate (AS) on the cross-section of asphalt concrete skeleton, and the water stability of SFP is the most affected by the total area of all aggregates (AA) on the cross-section. The research results show that continuous gradation has better applicability in areas with a significant temperature difference between four seasons but less rainfall. The single-particle size gradation is suitable for the area with slight temperature difference and high temperature and rain in summer, but not for the cold area.