研究了硅灰替代量(质量分数)为0％ 、5％ 、10％ 的复合硅酸盐胶凝体系浸泡在弱碱环境下,10％(质量分数)Na2 SO4溶液中侵蚀210 d时的侵蚀产物和含量.利用XRD、SEM、EDS对侵蚀产物进行了表征,通过K值法定量计算了硅灰复合硅酸盐胶凝体系中石膏的含量,通过分光光度法对硅灰复合硅酸盐胶凝体系中自由硫酸根离子以及总硫酸根离子含量进行了测定.结果表明,在弱碱环境下,10％Na2 SO4溶液中硅灰复合硅酸盐胶凝体系的主要侵蚀产物是石膏和钙矾石,侵蚀产物的形成引起膨胀开裂,且随硅灰掺量的增加,硅灰复合硅酸盐胶凝体系中的自由硫酸根离子及总硫酸根离子含量和侵蚀产物明显减少,膨胀率也随硅灰掺量的增加而减小,硅灰对复合硅酸盐胶凝体系的膨胀有一定的改善作用.%The composite silicate cementing systems with 0％ ,5％ and 10％ (mass fraction) cement replacement ratio by silica fume were immersed in 10％ (mass fraction) sodium sulfate and weak alkaline solution for 210 d ,the attack products and contents were studied .The attack products were characterized by XRD ,SEM and EDS .The contents of gypsum in composite silicate cementing system with silica fume were calculated by using K value ,the contents of free and total sulfate ion in composite silicate cementing system with silica fume were determined by spectrophotometry . The results show that the main attack products of composite silicate cementing system with silica fume are gypsum and ettringite in 10％ sodium sulfate and weak alkaline solution ,and the formation of attack products causes the specimen to expand and crack .The contents of free and total sulfate ion and the attack product in composite silicate cementing system with silica fume obviously decrease ,and the expansion rates decrease with the increase of silica fume .Silica fume has a certain improvement effect on the expansion of composite silicate cementing system with silica fume .
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