应用数字岩心对水工混凝土绝对渗透率的研究

Research on the Absolute Permeability of Hydraulic Concrete Using Digital Core

摘要: 渗透性是评价水工混凝土抗冻抗渗的重要指标，本文对水工混凝土进行快速冻融试验，采用工业CT扫描技术并结合Avizo软件建立三维模型，对渗透率的计算结果与流线结合进行可视化模拟，可清晰观察到流体流动流线及流体渗透压力分布，并得到绝对渗透率计算结果。以此对比分析两种水工混凝土在冻融作用下绝对渗透率的变化规律。结果表明：随着冻融次数的增加混凝土内部的裂隙逐渐变大，其连通性越好；相同配合比下的低热和中热水泥混凝土在冻融期间，其渗透率随冻融次数的增加而变大；低热水泥混凝土渗透率的变化率明显高于中热水泥混凝土。

Abstract: Permeability is an important indicator to evaluate the frost resistance and impermeability of hydraulic concrete. In this paper, the rapid freezing and thawing test of hydraulic concrete is carried out, and the industrial CT scanning technology and Avizo software are used to establish a three-dimensional model. The calculation results of permeability were visually simulated by combining streamline distribution with fluid flow, allowing for clear observation of fluid flow lines and fluid permeation pressure distribution. Absolute permeability calculation results were obtained. The variation patterns of absolute permeability of two types of hydraulic concrete under freeze- thaw conditions were compared and analyzed. The results indicated that with an increasing number of freeze-thaw cycles, the cracks within the concrete gradually expanded, which indicated better connectivity. For concrete with the same mix ratio, the permeability increased with the number of freeze-thaw cycles for low heat and medium heat cement concrete. The rate of permeability change for low heat cement concrete was significantly higher than that for medium heat cement concrete.