Research on the impact of environmental factors on the effective compaction time and microstructure of asphalt mixture

Environmental conditions had been one of the critical influencing factors in the pavement construction process. This study investigated the impact of environmental factors on the effective compaction time and microstructure of asphalt mixtures. Firstly, the impact of environmental factors on asphalt mixture compaction was studied using a simulation wheel rolling compactor, with effective compaction time analyzed based on the response surface method. Then, the rutting performance and microstructure changes were evaluated under varying conditions, and a mathematical model was developed linking rutting depth to microstructure parameters. The results showed that heat flow exchange significantly reduced the effective compaction time, while air velocity had the least effect. Wheel tracking tests revealed that asphalt mixtures compacted at elevated temperatures with minimized thermal losses exhibited superior performance, characterized by reduced rutting depth and improved internal stability. Microstructure analysis highlighted the critical role of medium pores in load distribution and structural stability. Under optimal molding conditions, the arrangement of aggregates had become more orderly, which had improved the interlocking performance among aggregates during testing. Statistical correlations confirmed that medium pore count, aggregate orientation, and vector magnitude significantly influenced rutting depth.