- freely available
Materials 2019, 12(9), 1561; https://doi.org/10.3390/ma12091561
2. Materials and Methods
2.1. Preparation of β-C2S
2.2. Carbonation of β-C2S Pastes
2.3. Test Methods
3. Results and Discussion
3.1. The Carbonation Products of β-C2S Pastes
3.2. Microstructure and Distribution of the Carbonation Products
3.3. Quantitative Analysis of the Carbonation Products
3.4. The Carbonation Hardening Mechanism of β-C2S Pastes
- After the carbonation curing of β-C2S for 24 h, a dense hardened paste was obtained. The hardened pastes are composed of pores, silica gel, calcium carbonate, and unreacted dicalcium silicate, with relative volume fractions of 1.3%, 42.1%, 44.9%, and 11.7%, respectively.
- The unreacted β-C2S center is coated with a layer of SiO2 gel, and the pores between the original β-C2S particles are filled with CaCO3.
- Rapid generation of a sufficient number of SiO2 gels and CaCO3 crystals, and the formation of network structures of these carbonation products are responsible for the carbonation hardening of the β-C2S mineral.
- These results obtained may provide a profound understanding of the carbonation reaction process and hardening mechanism of low-calcium silicate-based cementitious materials.
Conflicts of Interest
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