Self-leveling Epoxy Asphalt Concrete and its Rheological Properties during Mixing and Paving Periods

Abstract: In the context of increasing global climate change, bridge deck asphalt pavement (BDAP) is facing low-carbon precast assembly development needs, while the existing BDAP materials are difficult to take into account the advantages of multi-performance. To meet the precast assembly and service performance needs of BDAP, the balance design method and development procedures Self-leveling Epoxy Asphalt Concrete (SLEA) were proposed based on Guss asphalt concrete and epoxy asphalt concrete. The effects of different gradations and asphalt-aggregate ratios on the flow performance and mechanical strength of SLEA were investigated. The effect of different gradations and asphalt-aggregate ratios on the fluidity and mechanical strength of SLEA were investigated. The rheological properties of SLEA during the mixing and paving periods were analyzed. Referring to Bingham's plastic hydrodynamic properties, the generalized mixing viscosity of SLEA (GMV) was defined. The morphological characteristics of aggregates such as Needle Flake Index (NFI), Fractal Dimension (FD), Gradation Characteristics (k) and Scale Parameter (λ) were taken into consideration to establish the rheological property prediction model during the mixing and paving period. Results show that SLEA10 has good fluidity and mechanical strength, which can meet the requirements of prefabricated assembly and service performance. The gradation has a greater impact on the fluidity of SLEA10 while has a smaller impact on its strength. The fluidity mainly depends on the gradation coarseness and aggregate characteristics, while the strength after molding mainly depends on the consolidation of epoxy asphalt, and the influence degree of gradation coarseness is smaller. The established GMV prediction model can effectively predict the rheological performance of SLEA10. Based on the analysis results, it is recommended to choose the aggregate type with regular size, smaller surface roughness and finer gradation to realize the self-leveling and non-compaction function. Research findings could provide a reference for the design of SLEA and the assessment of rheological properties during the mixing and paving period, which is of great value and significance for the comprehensive performance improvement and high-quality development of asphalt pavements.