混凝土的水渗透性与其微观结构的关系研究

Research on the relationship between water permeability and microstructure of concrete

设计了水胶比不同的5种混凝土配合比,利用稳定渗流法测定了试验混凝土的水渗透系数,用MIP法测试了试验混凝土的总孔隙率、孔径分布等微观结构参数。结果表明:混凝土水渗透性与水胶比的关系在大水胶比时增加快;混凝土水渗透性与总孔隙率相关性较高,但掩盖了孔径分布对渗透性的影响;混凝土的水渗透性与100~1 000 nm的孔径贡献率的相关度很高,相关系数大于0.95,该孔径区间的孔径贡献率可用作评价混凝土渗透性的指标。

Five mixture proportions of concrete with different water-binder ratios have been designed in this paper.The water permeability coefficient of the test concrete was measured with the steady-state flow method and the total porosity and pore size distribution of the test concrete were measured by MIP.The results indicate that the relation between water permeability and water-binder ratio of concrete increases rapidly when the ratio of water-binder is high.The correlation between water permeability and total porosity of concrete is high,but the influence of pore size distribution on permeability is concealed.The water permeability of concrete has a high degree of correlation with the pore contribution ratio of 100 nm to 1 000 nm,with a correlation coefficient greater than 0.95,which can be used as an index to evaluate the permeability of concrete.