内掺氯离子与硫酸根离子在水泥净浆中的交互作用

The Interaction Between Chloride Ion and Sulfate Ion Doped in Cement Paste

模拟南海海水中阴离子浓度,采用氯离子、氯离子与硫酸根离子复合盐溶液分别作为拌合水制备水泥净浆,通过XRD定量分析、SEM及离子滴定等测试方法对不同标养龄期的水泥净浆进行微观分析,研究内掺氯离子和硫酸根离子在水泥净浆中的交互作用。结果表明,在内掺氯离子条件下,含氯离子的盐溶液作为拌合水拌合水泥净浆迅速生成Friedel盐(FS);氯离子的存在有抑制钙矾石(Ettringite,AFt)生成的作用;当氯离子浓度为3. 5%(质量分数)、硫酸根离子浓度为0. 5%(质量分数)时,硫酸根离子的引入促进了AFt向FS转化,提高化学结合氯离子的量;水化早期化学结合即氯离子参与反应形成FS占主导,硫酸根离子起到辅助作用;水化后期物理吸附即C-S-H凝胶对离子的吸附作用增强,对化学结合氯离子有一定的抑制作用。

In order to investigate the interaction of chloride ion and sulfate ion in the cement paste at different curing time,cement paste using the salt solution mixed with chloride ion and sulfate ion,simulating the concentration of anions in the sea water in the South China Sea,as mixing water was micro-analyzed by the test methods such as XRD quantitative analysis,SEM and ion titration test methods.Under the condition of chloride ion doped,the results show that:the cement paste mixed with the salt solution of chloride ion as mixing water produced FS immediately.The existence of chloride ions can take the effect of restraining the generation of ettringite.In the condition of the experiment concentration,lea-ding the sulfate ion promoted the conversion from AFt to FS and increased the amount of chemically bound chloride ion.Chemical bonding that the participation of chloride ions formed by reaction of FS dominates an important role and sulfate ions played a supporting role at the early hydration.At the later stage of hydration,the adsorption of C-S-H gel to ions which was called physical adsorption,having inhibitory effects on the chemical binding of chloride ion.