A New Method for Designing Dense Skeleton Asphalt Mixture Based on Meso Parameter

Abstract EN

At present, research on the internal structures of asphalt mixtures has mostly focused on the statistical analysis of their mesostructural components such as aggregates, voids, and asphalt mortars, in addition to the verification of the mechanical behaviour of the mixture through simulations.

Furthermore, the capacity of the research has not risen to a level where a design method to guide the design and optimisation of the asphalt mixture gradation has been formulated.

After an in-depth analysis of the existing evaluation parameters and standards for the asphalt mixture skeleton, this study proposes a new method for precise designing a dense skeleton asphalt mixture (DSAM) based on meso parameter.

The results indicate that the application of digital image processing (DIP) techniques to adjust the gradation increases the average coordination number (n¯c) and reduces the ratio of the quantity of coarse aggregate without contact point to the total quantity of coarse aggregate (C value).

This can effectively improve the meso parameters of the mixture so that the quality of the main skeleton is significantly enhanced; the process also has higher precision and demands less test work.

VCAmix(IMAGE) ≤ VCADRC and n¯c>1.6 while C < 20% can be used as qualitative and quantitative evaluation criterion for forming better main skeleton structure of coarse aggregate.

The new method of designing a DSAM based on meso parameter is intuitive and convenient, which considerably reduces the blindness and tediousness in the design of the asphalt mixture gradation.

The engineering example also proves that the asphalt mixture has an excellent pavement performance and verifies the feasibility of the proposed design method.