Abstract
This paper aims to investigate the effect of magnesium on the structure and chemical composition of calcium silicate hydrate at elevated temperature. Magnesium oxide, silica fume and calcium oxide were used in the preparation of MgO modified C–S–H gels with (Ca + Mg)/Si molar ratio of 0.8. The obtained solids were characterized with SEM, TEM-EDS, XRD, FT-IR, TG-DSC and 29Si NMR. The results show that the transformation from M–S–H to C–S–H occurs when Mg to Si molar ratio decreases to 0.4. A concentrated distribution of Mg, Si and Ca elements is observed with TEM-EDS, indicating that a new phase magnesium calcium silicate hydrate (M–C–S–H) is possibly formed.
| Original language | English |
|---|---|
| Article number | 117925 |
| Number of pages | 8 |
| Journal | Construction and Building Materials |
| Volume | 240 |
| DOIs | |
| Publication status | Published - 20 Apr 2020 |
| Externally published | Yes |
Bibliographical note
Publisher Copyright:© 2019 Elsevier Ltd
Funding
This research has been financially supported by the National Natural Science Foundation of China (project 51672199). The author thanks Dr. Xiaoyun Li from State Key Laboratory of Silicate Materials for Architectures for the assistance with the NMR tests.
Keywords
- Calcium silicate hydrate
- Elevated temperature
- Magnesium silicate hydrate
- Microstructure