Study on the Mix Design of Mastic Flow for Filling Based on Deviation Coefficient Method

To quantitatively evaluate the skeleton design of the MaFF method, this study addresses five dimensions: gradation control, test method, quantitative model, correction conversion, and design method. First, the deviation coefficient method is proposed based on the Talbot method. Unlike conventional design restricted to n = 0.3-0.7, this method takes the maximum density curve at n = 0.45 as the reference and enables flexible adjustment of Vag by controlling the 4.75 mm sieve passing rate. This provides a theoretical basis for discontinuous gradation design. Second, the wet mixing test is developed to overcome aggregate segregation and inadequate lubrication inherent in the dry tamping method, offering a new detection approach that better reflects the actual skeleton structure in the mixture. The optimum parameters were determined as 2% asphalt content, layered loading, one-sided tamping and 75 blows. Using 11 gradations, the wet mixing tests show that Vag increases from 24.13% to 38.29% as λ increases from 0 to 1.0, with a strong linear correlation (R² = 0.996). CT scanning validation indicates that the wet method results are 83-86% of those from 3D reconstruction, yielding a recommended reduction coefficient of 0.84. These findings systematically refine the MaFF method into a complete skeleton design framework. For the specific material system investigated (diabase aggregate, ultra-high-viscosity asphalt, maximum nominal particle size of 13.2 mm), this study provides a preliminary technical reference for FMA mix design. However, broader validation across diverse materials and field conditions is required before generalization.