Thermally induced microstructural changes in fly ash geopolymers: Experimental results and proposed model
This study presents a proposed model for thermally induced microstructural changes in fly ash geopolymers. Two paste mixes with different as-cured microstructures are evaluated for thermal resistance. One mix was a highly reacted, high-strength geopolymer with a compact microstructure and the other...
| Main Authors: | , , |
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| Format: | Journal Article |
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Blackwell Publishing Inc.
2015
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| Online Access: | http://hdl.handle.net/20.500.11937/46756 |
| _version_ | 1848757649168924672 |
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| author | Rickard, William Kealley, Cat Van Riessen, Arie |
| author_facet | Rickard, William Kealley, Cat Van Riessen, Arie |
| author_sort | Rickard, William |
| building | Curtin Institutional Repository |
| collection | Online Access |
| description | This study presents a proposed model for thermally induced microstructural changes in fly ash geopolymers. Two paste mixes with different as-cured microstructures are evaluated for thermal resistance. One mix was a highly reacted, high-strength geopolymer with a compact microstructure and the other mix had higher degree of unreacted fly ash resulting in a low strength, low-density geopolymer. Changes in the microstructure and bulk properties for each formulation were assessed at 100C temperature intervals up to 1000C using SEM, Q-XRD and physical testing. It was observed that the higher density and apparent lower permeability of the high-strength geopolymer led to it being more vulnerable to dehydration damage. Dimensional and phase changes also caused further strength losses before sintering at higher temperatures promoted strength gains. The low-strength geopolymer was not damaged by dehydration and was better able to accommodate volumetric changes; hence it exhibited an increase in strength after thermal exposure due to the sintering. From these results and others in the literature, a model has been proposed for thermally induced changes in fly ash geopolymers. |
| first_indexed | 2025-11-14T09:31:27Z |
| format | Journal Article |
| id | curtin-20.500.11937-46756 |
| institution | Curtin University Malaysia |
| institution_category | Local University |
| last_indexed | 2025-11-14T09:31:27Z |
| publishDate | 2015 |
| publisher | Blackwell Publishing Inc. |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | curtin-20.500.11937-467562019-04-09T03:05:33Z Thermally induced microstructural changes in fly ash geopolymers: Experimental results and proposed model Rickard, William Kealley, Cat Van Riessen, Arie This study presents a proposed model for thermally induced microstructural changes in fly ash geopolymers. Two paste mixes with different as-cured microstructures are evaluated for thermal resistance. One mix was a highly reacted, high-strength geopolymer with a compact microstructure and the other mix had higher degree of unreacted fly ash resulting in a low strength, low-density geopolymer. Changes in the microstructure and bulk properties for each formulation were assessed at 100C temperature intervals up to 1000C using SEM, Q-XRD and physical testing. It was observed that the higher density and apparent lower permeability of the high-strength geopolymer led to it being more vulnerable to dehydration damage. Dimensional and phase changes also caused further strength losses before sintering at higher temperatures promoted strength gains. The low-strength geopolymer was not damaged by dehydration and was better able to accommodate volumetric changes; hence it exhibited an increase in strength after thermal exposure due to the sintering. From these results and others in the literature, a model has been proposed for thermally induced changes in fly ash geopolymers. 2015 Journal Article http://hdl.handle.net/20.500.11937/46756 10.1111/jace.13370 Blackwell Publishing Inc. restricted |
| spellingShingle | Rickard, William Kealley, Cat Van Riessen, Arie Thermally induced microstructural changes in fly ash geopolymers: Experimental results and proposed model |
| title | Thermally induced microstructural changes in fly ash geopolymers: Experimental results and proposed model |
| title_full | Thermally induced microstructural changes in fly ash geopolymers: Experimental results and proposed model |
| title_fullStr | Thermally induced microstructural changes in fly ash geopolymers: Experimental results and proposed model |
| title_full_unstemmed | Thermally induced microstructural changes in fly ash geopolymers: Experimental results and proposed model |
| title_short | Thermally induced microstructural changes in fly ash geopolymers: Experimental results and proposed model |
| title_sort | thermally induced microstructural changes in fly ash geopolymers: experimental results and proposed model |
| url | http://hdl.handle.net/20.500.11937/46756 |