Phase transformations and properties evolution of Ca(OH)2 containing geopolymers as a function of temperature
| Autor: | B. P. Bezerra, H. R. M. Silva, M. R. Morelli, A. P. Luz |
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| Jazyk: | English<br />Portuguese |
| Rok vydání: | 2023 |
| Předmět: | |
| Zdroj: | Cerâmica, Vol 69, Iss 391, Pp 189-194 (2023) |
| Druh dokumentu: | article |
| ISSN: | 1678-4553 0366-6913 |
| DOI: | 10.1590/0366-69132023693913475 |
| Popis: | Abstract The composition-processing-structure-properties relationship of Na2O-Al2O3-SiO2-based geopolymers containing calcium sources is critical for the design of enhanced ceramic binders. This work evaluated the addition of 1-6 wt% of calcium hydroxide (CH) to a metakaolin-based geopolymer (prepared with NaOH 12 M and colloidal silica suspension) and how it affected the performance of the prepared samples after thermal treatments up to 1000 °C. The setting time, mechanical strength, porosity, density, permanent linear change, and phase and bond type evolution of the specimens with temperature were analyzed. The incorporation of 3 or 6 wt% of CH into the designed composition led to a fast hardening of the mixtures (1.7 h), resulting in geopolymers with high green mechanical strength (18.9 to 23.9 MPa). Nepheline and albite generation in the samples containing 6 wt% of CH resulted in a ceramic with improved cold crushing strength (45.2 MPa) and lower linear shrinkage (-10.5%) when compared to the calcium-free composition. |
| Databáze: | Directory of Open Access Journals |
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