羟乙基甲基纤维素对水泥水化的影响

Effect of Hydroxyethyl Methyl Cellulose on Cement Paste Hydration

摘要:

利用等温量热法、核磁共振谱(NMR)分析、X射线衍射相分析以及热重差示扫描量热(TGDSC)分析等方法，研究了羟乙基甲基纤维素及其掺量对水泥浆体水化放热、水化产物以及水化进程的影响.研究表明，羟乙基甲基纤维素能够延缓水泥早期水化，降低早期水化放热速率和水化放热量，但其对水泥中后期水化则没有明显的延缓作用；羟乙基甲基纤维素与水泥水化产物之间发生了相互作用，使得水泥浆体水化产物CSH凝胶中的硅氧四面体由一聚合态向一聚合态和二聚合态共存转变.

Abstract:

The hydration degree and the phase compositions of cement pastes were studied by using isothermal calorimetry,Nuclear magnetic resonance (NMR) spectroscopy, thermogravimetrydifferential scanning calorimetry (TGDSC) and Xray diffraction (XRD).Results show that hydroxyethyl methyl cellulose(HEMC) retards the earlyage hydration of cement paste, decreases the earlyage hydration rate and hydration heat of cement paste, but hardly retards the hydration of cement paste after the deceleratory period. Interactions between HEMC and cement hydration products take place. ［SiO4］4-tetrahedron monomers and dimers of calcium silicate hydrate (CSH) coexist in cement paste modified with HEMC, while only ［SiO4］4-tetrahedron monomers exist in the unmodified cement paste.