Analysis of drainage characteristics based on microstructure of porous asphalt mixture

作者:Xiao, Xin; Zhang, Xiao-Ning
来源:Journal of South China University of Technology(Natural Science Edition), 2016, 44(6): 113-120.
DOI:10.3969/j.issn.1000-565X.2016.06.018

摘要

In this paper, the influences of connecting air voids on the seepage characteristics of the porous asphalt mixture were investigated;the micro-distribution characteristics of the porous asphalt mixture is discussed based on industrial CT;a seepage-flow numerical model of the mixture is established;the internal flow characteristics of water within the porous asphalt mixture is analyzed by using the finite volume method;and the water flow characteristics affected by the diameter, the tortuosity and the minimum sectional size of the connecting air voids are discussed. The results indicate that (1) the air void diameter greatly influences the flow velocity and the velocity is approximately proportional to the square of the void diameter;(2) the larger the tortuosity is, the smaller the velocity and the flow are;(3) as the bending structure has little influence on the velocity and the flow, it can be neglected and the tortuosity is solely taken into consideration;(4) if the minimum sectional diameter of the connecting air voids is taken as the equivalent diameter of the whole water path for analyzing the seepage characteri-stics, the calculated permeability coefficient may be smaller than the actual value, so that a revision is necessary.

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