Characterization of reactive MgO-modified calcium sulfoaluminate cements upon carbonation
This study characterizes reactive MgO-modified calcium sulfoaluminate (CSA) cement upon carbonation. Paste samples were fabricated by replacing CSA cement with reactive MgO at levels of 0, 5, 10, and 20 wt%. The samples were cured for 56 days and further cured at a CO{sub 2} concentration of 3% for 28 days. MgO incorporation into the CSA cement favored the formation of monosulfate over ettringite. Externally supplied MgO in the CSA cement reduced Al uptake in C-A-S-H and formed hydrotalcite as a secondary phase, which is associated with a reduction in the carbonation degree. In addition, the incorporated MgO inhibited the carbonation of ettringite and monosulfate, while more C-A-S-H and aluminum hydroxide were formed in neat CSA cement upon carbonation, showing the nearly full decomposition of ettringite and monosulfate. The tetrahedral Al network of the MgO-modified sample was not altered upon carbonation, indicating that MgO modified the route of carbonation.
- OSTI ID:
- 23206253
- Journal Information:
- Cement and Concrete Research, Journal Name: Cement and Concrete Research Vol. 146; ISSN 0008-8846; ISSN CCNRAI
- Country of Publication:
- United States
- Language:
- English
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