Early hydration of C 3 A–gypsum pastes with Ca- and Na-lignosulfonate
| Autor: | Harald Justnes, Mette Rica Geiker, Tobias Danner, Rolf Andreas Lauten |
|---|---|
| Rok vydání: | 2016 |
| Předmět: |
Thermogravimetric analysis
Ettringite Gypsum Scanning electron microscope 0211 other engineering and technologies 02 engineering and technology Building and Construction engineering.material 021001 nanoscience & nanotechnology law.invention Thermogravimetry chemistry.chemical_compound Portland cement Crystallography chemistry law 021105 building & construction engineering General Materials Science Tricalcium aluminate 0210 nano-technology Dissolution Nuclear chemistry |
| Zdroj: | Cement and Concrete Research. 79:333-343 |
| ISSN: | 0008-8846 |
| DOI: | 10.1016/j.cemconres.2015.10.008 |
| Popis: | The early age phase development during the hydration of C 3 A–gypsum pastes with 1 and 4% Ca- or Na-lignosulfonate (CLS and NLS) was investigated using isothermal calorimetry, in-situ XRD, thermogravimetry, mass spectroscopy, and SEM analysis. With 1% CLS or NLS neither retardation of C 3 A dissolution nor retardation of ettringite formation was observed. When LS was added in a concentration of 4%, C 3 A and gypsum dissolution were slightly retarded. Gypsum depletion was delayed in all pastes containing CLS or NLS. 1% CLS or NLS increased the amount of AFm-phases formed within 24 h, while the amount of AFm was reduced with 4% CLS or NLS. The initial heat flow increased and the heat flow in the gypsum depletion peak was reduced with 1 and 4% CLS. With 4% NLS no initial heat flow was measured and the heat developed slowly within the first 15 min of hydration in the C 3 A–gypsum paste. |
| Databáze: | OpenAIRE |
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