Microstructural and microanalytical studies of sulfate attack. V. Comparison of different slag blends
Microstructural and microanalytical studies of sulfate attack. V. Comparison of different slag blends
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DOI：
10.1016/0008-8846(96)00090-7
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发表时间：
1996-07
影响因子：
11.4
通讯作者：
R. Gollop;H. Taylor
中科院分区：
文献类型：
--
作者：
R. Gollop;H. Taylor
用扫描电子显微镜、背散射电子（BSE）成像和X射线微区分析研究了几种矿渣混合物在0.25 mol I− 1硫酸钠或硫酸镁溶液中储存的糊状物。一般来说，侵蚀导致C-S-H脱钙和钙矾石的形成。用Na 2SO 4，很少或没有石膏形成，但用MgSO 4，水镁石，结晶不良的蛇纹石（M3 S2 H2）和石膏也形成。目视检查和BSE图像表明，由Na 2SO 4的攻击的相对敏感性的共混物的增加与可用于形成钙矾石的Al 2 O3的含量，这包括存在于AFm相，但不存在于C-S-H或水滑石。的等级顺序的MgSO 4的攻击的敏感性大致相似，由Na 2 SO 4，但矿渣混合物表现更差，相对于普通波特兰水泥或抗硫酸盐波特兰水泥。通过使用高比例的矿渣、低Al 2 O3含量的矿渣或抗硫酸盐的波特兰水泥以及通过用额外的硫酸钙补充波特兰水泥组分中的石膏，有利于耐Na 2SO 4侵蚀。
Pastes of several slag blends that had been stored in 0.25 mol I−1solutions of sodium or magnesium sulfate were studied by scanning electron microscopy using backscattered electron (BSE) imaging and X-ray microanalysis of polished sections. In general, attack resulted in decalcification of C-S-H and the formation of ettringite. With Na2So4, little or no gypsum was formed, but with MgSO4, brucite, poorly crystalline serpentine (M3S2H2) and gypsum were also formed. Visual examinations and BSE images indicated that the relative susceptibility of the blends to attack by Na2SO4increases with the content of Al2O3available for the formation of ettringite; this includes that present in AFm phases but not that present in C-S-H or hydrotalcite. The rank order of susceptibility to attack by MgSO4was broadly similar to that by Na2SO4, but the slag blends performed more poorly relative to plain Portland cement or sulfate-resisting Portland cement. Resistance to attack by Na2SO4, is favoured by the use of high proportions of slag, slags low in Al2O3, or sulfate resisting Portland cements and by supplementing the gypsum in the Portland cement component by additional calcium sulfate.