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利用高分辨固体核磁共振仪结合去卷积技术,定量分析了粉煤灰水泥浆体中水泥和粉煤灰的水化程度以及C-S-H凝胶中硅氧-铝氧链平均长度,同时研究了粉煤灰火山灰反应对C-S-H结构的影响。结果表明:水化3 d时,系统中约47%的水泥和14%的粉煤灰参与了水化反应,C-S-H平均链长为3.2;水化120d时,水泥和粉煤灰的水化程度分别为89%和33%,C-S-H平均链长约为3.8,远大于纯水泥浆体中C-S-H的平均链长(为2.7)。水化3 d时粉煤灰玻璃相结构中的Si—O—Si,Si—O—和Al—Al共价键断裂,形成了单体硅酸根和单体铝酸根,这些单体结构桥连体系中的二聚体单元进而提高了C-S-H平均链长。粉煤灰掺入并不会因为C-S-H聚合度提高以及ACL增加就能促进粉煤灰水泥浆体强度。
Using high-resolution solid-state NMR spectroscopy combined with deconvolution techniques, the degree of hydration of cement and fly ash in fly ash cement pastes and the average length of silicon-oxygen-aluminum-oxygen chains in CSH gels were quantitatively analyzed. Powders were also studied. Influence of Pozzolanic Ash Reaction on CSH Structure in Coal Ash . The results show that about 37% of hydration, about 47% of cement and 14% of fly ash participate in the hydration reaction, the average chain length of CSH is 3.2, and the degree of hydration of cement and fly ash at 120d hydration The average chain length of CSH was about 3.8, which was 89% and 33%, respectively, much larger than the average chain length of CSH in the pure cement slurry (2.7). The covalent bonds of Si—O—Si, Si—O— and Al—Al in the glass structure of fly ash were broken during hydration for 3 days, and monomeric silicates and monomeric aluminates were formed. These monomer structures were bridged. The dimer units in the system then increase the average chain length of the CSH. The incorporation of fly ash will not promote the strength of fly ash cement slurry because of the increase of C-S-H polymerization degree and the increase of ACL.