This study simulated interfacial transition zone (ITZ) by controlling aggregate in type, size, shape, amount and placement to experimentally investigate diffusion coefficients in ITZ in comparison of mortar using an accelerated chloride diffusion test and a newly developed oxygen diffusion test. The water-to- cement ratios (w/c) of 0.55, 0.50, 0.45, 0.40 and 0.35 were used to evaluate w/c effect on diffusion. The results indicated that the simulated ITZ was successfully used to investigate the effect of w/c on chloride and oxygen diffusion properties in ITZ. The diffusion coefficient in ITZ was much larger than that in mortar. An inflexion of diffusion coefficient in ITZ was found with w/c reducing. A critical index M (ratio of D_ITZ and D_mor) was used to determine whether the porosity or the ratio of ITZ porosity and mortar porosity dominated diffusion coefficient in ITZ. The relationship between effective diffusion coefficient (overall diffusion coefficient) and M was proposed. Additionally, oxygen diffusion coefficient was much higher than chloride diffusion coefficient.

这项研究通过控制聚集体的类型，大小，形状，数量和位置来模拟界面过渡带（ITZ），以实验方式研究砂浆中ITZ的扩散系数，并使用加速氯化物扩散测试和最新开发的氧气扩散测试进行了比较。水灰比为0.55、0.50、0.45、0.40和0.35的w / c用于评估w / c对扩散的影响。结果表明，模拟的ITZ已成功用于研究w / c对ITZ中氯和氧扩散特性的影响。ITZ中的扩散系数远大于砂浆中的扩散系数。发现w / c减小，ITZ中扩散系数增加。临界指数M（D _ITZ和D _mor的比率）是用来确定孔隙度或ITZ孔隙度与砂浆孔隙度之比是否决定了ITZ中的扩散系数。提出了有效扩散系数（总扩散系数）与M的关系。此外，氧的扩散系数远高于氯的扩散系数。