The first 20 hours of geopolymerization: An in situ WAXS study of flyash-based geopolymers
This study followed the first 20 h of flyash geopolymerization at 70 °C using time resolved Wide Angle X-ray Scattering (WAXS). The extent of dissolution of the amorphous phase of the flyash was determined to range from 29% to 54% for the different formulations trialed. The dissolution rate of the f...
| Main Authors: | , |
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| Format: | Journal Article |
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mdpi
2016
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| Online Access: | http://hdl.handle.net/20.500.11937/50979 |
| _version_ | 1848758583350525952 |
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| author | Williams, Ross Van Riessen, Arie |
| author_facet | Williams, Ross Van Riessen, Arie |
| author_sort | Williams, Ross |
| building | Curtin Institutional Repository |
| collection | Online Access |
| description | This study followed the first 20 h of flyash geopolymerization at 70 °C using time resolved Wide Angle X-ray Scattering (WAXS). The extent of dissolution of the amorphous phase of the flyash was determined to range from 29% to 54% for the different formulations trialed. The dissolution rate of the flyash significantly reduced after the first 5 h for all samples. During the formation stage of the geopolymer there were significant temporal variations in the chemistry of the dissolved solution due to the rate of flyash dissolution, with a relative standard deviation of 20%, 57% and 24% for the Si/Al, Na/Al and H/Si ratios, respectively. Utilizing the Power Law, scattering in the low angle region of the WAXS pattern combined with the geopolymer peak area yielded a measure which correlated with the compressive strength-providing a new method to measure the flyash dissolution and geopolymer formation processes independently. The evolution of several zeolite-like phases was followed, noting there are different formation mechanisms involved even within the same sample. Four samples were examined with compressive strengths ranging from 14(2)-50(9) MPa, each was synthesized with flyash from Collie Power Station (Western Australia) activated with sodium silicate solution of varying concentrations. |
| first_indexed | 2025-11-14T09:46:18Z |
| format | Journal Article |
| id | curtin-20.500.11937-50979 |
| institution | Curtin University Malaysia |
| institution_category | Local University |
| last_indexed | 2025-11-14T09:46:18Z |
| publishDate | 2016 |
| publisher | mdpi |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | curtin-20.500.11937-509792017-09-13T15:35:34Z The first 20 hours of geopolymerization: An in situ WAXS study of flyash-based geopolymers Williams, Ross Van Riessen, Arie This study followed the first 20 h of flyash geopolymerization at 70 °C using time resolved Wide Angle X-ray Scattering (WAXS). The extent of dissolution of the amorphous phase of the flyash was determined to range from 29% to 54% for the different formulations trialed. The dissolution rate of the flyash significantly reduced after the first 5 h for all samples. During the formation stage of the geopolymer there were significant temporal variations in the chemistry of the dissolved solution due to the rate of flyash dissolution, with a relative standard deviation of 20%, 57% and 24% for the Si/Al, Na/Al and H/Si ratios, respectively. Utilizing the Power Law, scattering in the low angle region of the WAXS pattern combined with the geopolymer peak area yielded a measure which correlated with the compressive strength-providing a new method to measure the flyash dissolution and geopolymer formation processes independently. The evolution of several zeolite-like phases was followed, noting there are different formation mechanisms involved even within the same sample. Four samples were examined with compressive strengths ranging from 14(2)-50(9) MPa, each was synthesized with flyash from Collie Power Station (Western Australia) activated with sodium silicate solution of varying concentrations. 2016 Journal Article http://hdl.handle.net/20.500.11937/50979 10.3390/MA9070552 mdpi fulltext |
| spellingShingle | Williams, Ross Van Riessen, Arie The first 20 hours of geopolymerization: An in situ WAXS study of flyash-based geopolymers |
| title | The first 20 hours of geopolymerization: An in situ WAXS study of flyash-based geopolymers |
| title_full | The first 20 hours of geopolymerization: An in situ WAXS study of flyash-based geopolymers |
| title_fullStr | The first 20 hours of geopolymerization: An in situ WAXS study of flyash-based geopolymers |
| title_full_unstemmed | The first 20 hours of geopolymerization: An in situ WAXS study of flyash-based geopolymers |
| title_short | The first 20 hours of geopolymerization: An in situ WAXS study of flyash-based geopolymers |
| title_sort | first 20 hours of geopolymerization: an in situ waxs study of flyash-based geopolymers |
| url | http://hdl.handle.net/20.500.11937/50979 |