This study utilized a novel in situ fiber-optic Raman probe to continuously monitor the hydration progress of tricalcium silicate (C3S) and dicalcium silicate (C2S) without the need for sampling, from early hydration stage to later stages, and from fresh to hardened states of paste samples. By virtue of the remarkable ability of this technique in characterizing either dry or wet and crystalline or amorphous samples, the hydration processes of C3S and C2S pastes with different water-to-solid (w/s) ratios could be monitored from the start of the hydration reaction. The main hydration products, calcium silicate hydrate (C–S–H) and portlandite/calcium hydroxide (CH), have been successfully identified and continuously monitored for variations in their respective amounts in situ. The effect of w/s ratio on the hydration processes of C3S and C2S pastes was also considered. Meanwhile, the x-ray diffraction (XRD) and thermogravimetric analysis (TGA) results showed a great correlation with the in situ Raman test results about hydration products, which demonstrated the reliability of this technology. Moreover, the signal-to-noise ratio (SNR) of this Raman probe is significantly superior to existing technologies for in situ fiber-optic Raman spectroscopy. This remote fiber-optic Raman probe enables the use of Raman spectroscopy in future construction projects for on-site monitoring and evaluation of health conditions and performance of concrete structures.
B. Zhang et al., "In Situ Monitoring Of The Hydration Of Calcium Silicate Minerals In Cement With A Remote Fiber-optic Raman Probe," Cement and Concrete Composites, vol. 142, article no. 105214, Elsevier, Sep 2023.
The definitive version is available at https://doi.org/10.1016/j.cemconcomp.2023.105214
Civil, Architectural and Environmental Engineering
Electrical and Computer Engineering
Keywords and Phrases
Dicalcium silicate (C S) 2; Fiber-optic Raman probe; Hydration process; In situ Raman spectroscopy; Real-time continuous monitoring; Tricalcium silicate (C S) 3
International Standard Serial Number (ISSN)
Article - Journal
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01 Sep 2023