电场作用下水泥基材料的MgSO_4侵蚀  

MgSO_4 Attack of Cement Based Materials under Electrical Field

作　　者：罗遥凌[1] 殷吉强 王冲[1] 方正[1] 

机构地区：[1]重庆大学材料科学与工程学院,重庆400045 [2]重庆市武隆区建设工程质量监督站,重庆408500

出　　处：《湖南大学学报（自然科学版）》2017年第6期69-74,共6页Journal of Hunan University:Natural Sciences

基　　金：国家自然科学基金资助项目(51572038)~~

摘　　要：已有研究表明电场能够加速水泥基材料硫酸盐侵蚀并可用于快速评价水泥基材料的抗硫酸盐侵蚀性能,但以上研究均是针对电场作用下Na_2SO_4溶液的侵蚀,鲜有研究电场作用下MgSO_4溶液侵蚀行为.本文利用抗蚀系数反映电场对水泥基材料MgSO_4侵蚀程度影响,利用XRD和SEM/EDS分析电场作用下水泥基材料的MgSO_4侵蚀机理.研究表明:电场加速了水泥基材料MgSO_4侵蚀破坏;在电场作用下SO_4^(2-)离子从阴极进入试件内部,首先与Ca(OH)_2反应生成石膏,生成的石膏继续与C_3A的水化产物反应生成钙矾石,当C_3A的水化产物反应完毕,从外界进入的SO_4^(2-)离子继续与Ca(OH)_2反应生成石膏,其侵蚀产物以石膏为主,其次是钙矾石.Existing studies have shown that electrical field accelerates the sulfate attack, and thus it can be used to rapidly evaluate the sulfate resistance of cement based materials. However, Na2SO4 was mainly used as the corrosion medium in these studies and there were fewer researches on MgSO4 as attack solution under electrical field. Therefore, in this paper, the mechanism of magnesium sulfate attack under electric field was analyzed by means of corrosion resistance coefficient, X-ray diffraction （XRD） and Scanning E- lectron Microscope （SEM） equipped with Energy Dispersive Spectrometer （EDS）. The results showed that sulfate ions migrated into the specimens under the action of electrical field and reacted with portlandite to produce gypsum, which reacted further with the hydration products of Ca A to form ettringite. After the hydration products of C3A were consumed, the penetrated sulfate ions continued to react with portlandite. As a result, the main attack product was gypsum, followed by ettringite.

关 键 词：电场影响 水泥基材料 加速 MgSO4侵蚀 

分 类 号：TU528[建筑科学—建筑技术科学]