Relations between the structural characteristics and compressive strength in metakaolin based geopolymers with different molar Si/Al ratios
| Autor: | Sezen Soyer-Uzun, Isil Ozer |
|---|---|
| Rok vydání: | 2015 |
| Předmět: |
Materials science
Scanning electron microscope Process Chemistry and Technology Analytical chemistry Microstructure Surfaces Coatings and Films Electronic Optical and Magnetic Materials Amorphous solid Geopolymer chemistry.chemical_compound Compressive strength chemistry Materials Chemistry Ceramics and Composites Sodalite Fourier transform infrared spectroscopy Composite material Metakaolin |
| Zdroj: | Ceramics International. 41:10192-10198 |
| ISSN: | 0272-8842 |
| DOI: | 10.1016/j.ceramint.2015.04.125 |
| Popis: | X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM) and compressive strength measurements were performed to fully characterize metakaolin-based geopolymers with molar Si/Al ratios of 1.12, 1.77 and 2.20 in order to establish structure–performance relationships in this system. XRD results showed that the geopolymer samples with Si/Al ratio of 1.12 contained crystalline components, namely zeolite A and/or sodalite phases, whereas geopolymers with Si/Al ratio of 1.77 and 2.20 were ‘X-ray amorphous’ with minor amount of quartz content. The microstructure as revealed from SEM verified that geopolymer with Si/Al ratio of 1.12 consisted of crystalline components whereas samples with Si/Al ratio of 1.77 and 2.20 included amorphous microstructures. The position and width of the main band in FTIR spectra is found to systematically increase with increasing molar Si/Al ratio. The intensity of this band decreased with increasing Si content in the system indicating increased geopolymerization. This increase was related with formation of a three dimensional structure with stronger bonding environment with increasing SiO2 incorporation in geopolymer matrix. Compressive strength of these samples were also found to increase systematically with increasing molar Si/Al ratio. The evolution of the structural characteristics obtained from spectroscopy, diffraction and microscopy are shown to be directly correlated with the results of compressive strength measurements performed on these geopolymers. |
| Databáze: | OpenAIRE |
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