Influence of Nano-SiO₂ and Nano-TiO₂ on Early Hydration of Calcium Sulfoaluminate Cement

Abstract:

Calcium sulfoaluminate (CSA) cements were currently receiving a lot of attention because their manufacture produced less CO₂ than ordinary Portland cement (OPC). However, it was essential to understand all parameters which might affect the hydration process. This work dealt with the effect of two nanostructured materials, such as nanoSiO₂ (NS) and nanoTiO₂ (NT), on the properties of CSA pastes during early hydration. Isothermal calorimetry, X-ray diffraction (XRD) and Scanning electron microscopy (SEM) were used to analyze the pastes. Results indicated that the influence of NS and NT on the early hydration of CSA showed different: when NS and NT were added by 5% (mass fraction), the early hydration of CSA cement can be significantly promoted by NS, and slightly accelerated by NT. X-ray diffraction and SEM analysis results showed that both of NS and NT can improve the microstructure of the cement pastes, which made the cement stone more uniform and dense. For the difference, during cement hydration, except for nucleation function, NS had a high pozzolanic activity. Whereas,the effect of NT on microstructure of hardened CSA-cement was mainly due to its seeding effect.

• Periodical: Key Engineering Materials (Volume 599)
• Pages: 39-45
• DOI: https://doi.org/10.4028/www.scientific.net/KEM.599.39
• Online since: February 2014
• Authors: Bao Guo Ma, Hai Nan Li*, Yan Chao Zhu, Lei Han, Xiang Guo Li
• Keywords: Calcium Sulfoaluminate Cement, Hydration Heat, Nano-SiO₂, Nano-TiO₂

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