Deciphering the Sulfate Attack of Cementitious Materials by High-Resolution Micro-X-ray Diffraction

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• 作者：Moritz C. Schlegel ; Urs Mueller ; Ulrich Panne ; Franziska Emmerling
• 刊名：Analytical Chemistry
• 出版年：2011
• 出版时间：May 15, 2011
• 年：2011
• 卷：83
• 期：10
• 页码：3744-3749
• 全文大小：902K
• 年卷期：v.83,no.10(May 15, 2011)
• ISSN：1520-6882

文摘

The durability of cementitious materials depends, among others, on their resistance against chemical attack during the service life of a building. Here, we present an approach to analyze changes in the phase composition due to chemical attack in the form of sulfate ingress within the microstructure. Micro-X-ray (渭X-ray) diffraction using synchrotron radiation in Debye鈥揝cherrer (transmission) geometry allowed a spatial resolution of 10 渭m. Phase transformations in the wake of damaging processes were observed in a detailed high-resolution imaging study. In comparison, samples containing supplementary cementitious materials were investigated and used to reconstruct the influence of different degeneration processes in detail. Additionally, reaction fronts within the bulk were localized by micro-X-ray fluorescence analysis. The experimental setup provided the possibility for analyzing the phase assemblage of a given sample without destroying the microstructure. The specimens for phase analysis are thick sections of the primary material and can be used for further microscopic analysis of the microstructure and microchemistry, e.g., scanning electron microscopy鈥揺nergy-dispersive X-ray spectroscopy (SEM鈥揈DX) or Raman spectroscopy.