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This paper investigates the effects of air void topology on hydraulic conductivity in asphalt mixtures with porosity in the range 14%-31%. Virtual asphalt pore networks were generated using the Intersected Stacked Air voids (ISA) method, with its parameters being automatically adjusted by the means of a differential evolution optimisation algorithm, and then 3D printed using transparent resin. Permeability tests were conducted on the resin samples to understand the effects of pore topology on hydraulic conductivity. Moreover, the pore networks generated virtually were compared to real asphalt pore networks captured via X-ray Computed Tomography (CT) scans. The optimised ISA method was able to generate realistic 3D pore networks corresponding to those seen in asphalt mixtures in term of visual, topological, statistical and air void shape properties. It was found that, in the range of porous asphalt materials investigated in this research, the high dispersion in hydraulic conductivity at constant air void content is a function of the average air void diameter. Finally, the relationship between average void diameter and the maximum aggregate size and gradation in porous asphalt materials was investigated.
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... This moisture damage is also linked with undue high temperature cracking and deflection. The initial phase of detecting the problems affected by the existence of moisture within pavement is estimating the permeability of hot mix asphalt (HMA) (Abou-foul & Chiarelli, 2018). ...
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This paper explains the effect of air void topology on the hydraulic conductivity and clogging properties of pervious asphalt. Cylinders of asphalt mixtures with a single type of aggregates and five gradations have been manufactured, Computed Tomography (CT) scanned and, transparent resin blocks with equivalent pore structure have been 3D printed to allow the visual inspection and quantification of the clogs. Geometrical properties, such as the macroporosity, air void diameter, Euler number and tortuosity, have been recorded from the CT scans. Furthermore, the hydraulic conductivity and clogging susceptibility of the asphalt cylinders and 3D-printed resin blocks have been measured.
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Influence of air voids characteristics on the hydraulic conductivity of asphalt mixture
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