Fractal dimension analysis of the fine aggregate gradation of interlocking skeleton asphalt mixture

Abstract

By analyzing the fine aggregate gradation scales from standards, fine aggregate in the asphalt mixture is regarded as a whole research object and fractal dimensions X of the samples were obtained by linear regression and (AC-13) is 2.43–2.56, Sup-13 is 2.28–2.54, SMA-13 is 2.66–2.88 and SAC-13 is 2.54–2.73. In the dense gradation mixture, there are little different between fractal dimensions of coarse and fine aggregates but it makes sense for skeleton asphalt mixture. For a given coarse aggregate gradation and the same percentage of coarse aggregates, the compressive strengths and splitting strengths of the asphalt mixture are studied when the fractal dimensions are selected as 2.60, 2.65 and 2.70, respectively. When asphalt-stone ratio is less than optimal asphalt-stone ratio, the higher compressive strength is, the bigger X can be gotten. When asphalt-stone ratio is larger than optimal asphalt-stone ratio, little difference of compressive strength can be observed under these three conditions. The largest splitting strength can be got when X is 2.65, and larger splitting strength can be observed with the ascending of the asphalt-stone ratio.