Analyzing the Effects of Calcium Nitrate over White Portland Cement: A Multi-Scale Approach
Calcium nitrate is considered a promising accelerator in cement-based composites, with high potential in 3D printing and cold cement concreting. The effect induced by the composition of calcium nitrate tetrahydrate (CN) accelerator into white Portland cement is evaluated here from three perspectives...
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MDPI AG
2022-12-01
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| Series: | Materials |
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| Online Access: | https://www.mdpi.com/1996-1944/16/1/371 |
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| author | Mihai Marius Rusu Adriana Vulpoi Cristian Vilau Cristian Mircea Dudescu Petru Păşcuţă Ioan Ardelean |
| author_facet | Mihai Marius Rusu Adriana Vulpoi Cristian Vilau Cristian Mircea Dudescu Petru Păşcuţă Ioan Ardelean |
| author_sort | Mihai Marius Rusu |
| collection | DOAJ |
| description | Calcium nitrate is considered a promising accelerator in cement-based composites, with high potential in 3D printing and cold cement concreting. The effect induced by the composition of calcium nitrate tetrahydrate (CN) accelerator into white Portland cement is evaluated here from three perspectives: (1) Fresh cement paste properties in terms of setting time and slump, (2) mechanical properties of hardened cement samples at 7 and 28 days and (3) material characteristics in terms of structure and porosity that further link the presence of the accelerator with the macroscopic performances. The compressive and flexural strength of the hardened samples, evaluated after 7 and 28 days of hydration, indicate a non-monotonous trend with CN concentration. Crystalline phase composition is investigated using X-ray diffraction (XRD). The morphology and texture are analyzed at the flexure interface by visual inspection and electron microscopy. Complementary, the porous features are investigated by NMR-relaxometry on dry and cyclohexane-filled samples. The studies confirm that CN promotes changes in the composition and morphology of hydrates, while a trend of increase in capillary porosity is outlined as well. This competition between multiscale effects may be quantified by NMR and complementary techniques to further clarify the mechanical behavior of such composites. |
| first_indexed | 2024-03-11T09:55:02Z |
| format | Article |
| id | doaj.art-6f80056f214940c4bc796816b9170ab8 |
| institution | Directory Open Access Journal |
| issn | 1996-1944 |
| language | English |
| last_indexed | 2024-03-11T09:55:02Z |
| publishDate | 2022-12-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Materials |
| spelling | doaj.art-6f80056f214940c4bc796816b9170ab82023-11-16T15:50:44ZengMDPI AGMaterials1996-19442022-12-0116137110.3390/ma16010371Analyzing the Effects of Calcium Nitrate over White Portland Cement: A Multi-Scale ApproachMihai Marius Rusu0Adriana Vulpoi1Cristian Vilau2Cristian Mircea Dudescu3Petru Păşcuţă4Ioan Ardelean5Department of Physics and Chemistry, Technical University of Cluj-Napoca, 400114 Cluj-Napoca, RomaniaNanostructured Materials and Bio-Nano-Interfaces Center, Institute of Interdisciplinary Research in Bio-Nano-Sciences, Babes-Bolyai University, T. Laurean 42, 400271 Cluj-Napoca, RomaniaDepartment of Mechanical Engineering, Technical University of Cluj-Napoca, 400114 Cluj-Napoca, RomaniaDepartment of Mechanical Engineering, Technical University of Cluj-Napoca, 400114 Cluj-Napoca, RomaniaDepartment of Physics and Chemistry, Technical University of Cluj-Napoca, 400114 Cluj-Napoca, RomaniaDepartment of Physics and Chemistry, Technical University of Cluj-Napoca, 400114 Cluj-Napoca, RomaniaCalcium nitrate is considered a promising accelerator in cement-based composites, with high potential in 3D printing and cold cement concreting. The effect induced by the composition of calcium nitrate tetrahydrate (CN) accelerator into white Portland cement is evaluated here from three perspectives: (1) Fresh cement paste properties in terms of setting time and slump, (2) mechanical properties of hardened cement samples at 7 and 28 days and (3) material characteristics in terms of structure and porosity that further link the presence of the accelerator with the macroscopic performances. The compressive and flexural strength of the hardened samples, evaluated after 7 and 28 days of hydration, indicate a non-monotonous trend with CN concentration. Crystalline phase composition is investigated using X-ray diffraction (XRD). The morphology and texture are analyzed at the flexure interface by visual inspection and electron microscopy. Complementary, the porous features are investigated by NMR-relaxometry on dry and cyclohexane-filled samples. The studies confirm that CN promotes changes in the composition and morphology of hydrates, while a trend of increase in capillary porosity is outlined as well. This competition between multiscale effects may be quantified by NMR and complementary techniques to further clarify the mechanical behavior of such composites.https://www.mdpi.com/1996-1944/16/1/371calcium nitrate tetrahydratewhite Portland cementcement paste hardeningmicrostructureelectron microscopyNMR relaxometry |
| spellingShingle | Mihai Marius Rusu Adriana Vulpoi Cristian Vilau Cristian Mircea Dudescu Petru Păşcuţă Ioan Ardelean Analyzing the Effects of Calcium Nitrate over White Portland Cement: A Multi-Scale Approach Materials calcium nitrate tetrahydrate white Portland cement cement paste hardening microstructure electron microscopy NMR relaxometry |
| title | Analyzing the Effects of Calcium Nitrate over White Portland Cement: A Multi-Scale Approach |
| title_full | Analyzing the Effects of Calcium Nitrate over White Portland Cement: A Multi-Scale Approach |
| title_fullStr | Analyzing the Effects of Calcium Nitrate over White Portland Cement: A Multi-Scale Approach |
| title_full_unstemmed | Analyzing the Effects of Calcium Nitrate over White Portland Cement: A Multi-Scale Approach |
| title_short | Analyzing the Effects of Calcium Nitrate over White Portland Cement: A Multi-Scale Approach |
| title_sort | analyzing the effects of calcium nitrate over white portland cement a multi scale approach |
| topic | calcium nitrate tetrahydrate white Portland cement cement paste hardening microstructure electron microscopy NMR relaxometry |
| url | https://www.mdpi.com/1996-1944/16/1/371 |
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