Design of a Rut-Resistant Asphalt Mixture Using the Simplified Multilevel Mixing Method

Abstract

The multilevel mixing method for aggregate gradation design was optimized based on the division of the functions of coarse and fine aggregates. The mixing procedures were simplified. The mixing process for fine aggregates was omitted to avoid segregation during the mixing process for coarse and fine aggregates. The calculation method for the ratio of coarse aggregates to fine aggregates was redesigned to consider the volume interference of mineral powder. The volume relationship between mineral powder and asphalt was established by controlling their ratio. Accordingly, the optimal asphalt aggregate ratio was obtained to guarantee the anti-rutting performance of the mixture. The performances of the mixtures designed using this new method were verified via the Marshall stability test, and their rut-resistant capabilities were compared with those of the AC-13 and SMA-13 asphalt mixtures. Results show that the technical indicators of the MLB-13 mixture fulfill the relevant requirements of the standard and demonstrate reasonable rut-resistant performance.