多离子在混凝土中传输及其对SO4^2-迁移的影响研究

Study on the multi-species ionic transport in concrete and its influence on migration of SO4^2-

试验研究了混凝土试样在Na2SO4、MgSO4、MgSO4/NaCl 3种溶液体系中的腐蚀行为,测定了不同离子在混凝土内部的分布,并采用灰色关联法分析Mg^2+、Na^+、Cl^-与SO4^2-扩散系数之间的关联度,揭示了混凝土内部多离子传输过程中Mg^2+、Na^+和Cl^-对SO4^2-迁移的影响规律SO4^2-研究表明:(1)Mg^2+能够降低SO4^2-在混凝土中的表面离子浓度,但提高了SO4^2-在混凝土中的扩散系数;(2)在Mg^2+存在的条件下,同时含有的Cl^-能够提高Mg^2+的表面离子浓度和在混凝土中的含量,间接地降低了SO4^2-的表面离子浓度,提高了其在混凝土中的扩散系数。

The corrosion behaviors of concrete samples in three solution systems Na2SO4,MgSO4 and MgSO4/NaCl were studied.The distribution of ingressive ions in concrete was determined.The correlation between diffusion coefficients of magnesium,sodium,chloride,sulfate was explored by means of grey correlation analysis method.The influences of magnesium,sodium and chloride on the migration of sulfate during the ingression of multi-species ionic in concrete were revealed.The results showed that(1)magnesium can reduce the surface ionic concentration of sulfate,but it enhances the diffusion coefficient of sulfate in concrete.(2)In the presence of magnesium,the simultaneous existence of chloride can increase the surface ionic concentration and the content of magnesium in concrete,and indirectly reduce the surface ionic concentration of sulfate ions and increase its diffusion coefficient in concrete.