Influence of Fly Ash Denitrification on Properties of Hybrid Alkali-Activated Composites
This article deals with the possibility of partial replacement of blast furnace slag (GGBFS) with fly ash after denitrification (FAD) in alkali-activated materials. Physical-mechanical and durability properties were tested, hydration reaction was monitored, and infrared spectroscopy was performed. R...
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| Format: | Article |
| Language: | English |
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MDPI AG
2022-04-01
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| Series: | Crystals |
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| Online Access: | https://www.mdpi.com/2073-4352/12/5/633 |
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| author | Lukáš Procházka Jana Boháčová Barbara Vojvodíková |
| author_facet | Lukáš Procházka Jana Boháčová Barbara Vojvodíková |
| author_sort | Lukáš Procházka |
| collection | DOAJ |
| description | This article deals with the possibility of partial replacement of blast furnace slag (GGBFS) with fly ash after denitrification (FAD) in alkali-activated materials. Physical-mechanical and durability properties were tested, hydration reaction was monitored, and infrared spectroscopy was performed. Results were compared between mixtures prepared with fly ash without denitrification (FA), and also with a mixture based only on GGBFS. The basic result is that hybrid alkali-systems with FAD show similar trends to FA. The significant effect of fly ash is manifested in terms of its resistance to freeze-thaw processes. Reactions in a calorimeter show a slower development of reactions with increasing replacement of GGBFS due to the lower reactivity of the fly ash. Through testing the leaching resistance, a decrease in flexural strength was found. This may be due to the descaling of the main hydration product, C–(A)–S–H gel. After 28 days of maturation, compressive strengths of all monitored mixtures ranged from 96 to 102 MPa. The flexural strengths ranged from 6.8 to 8.0 MPa. After 28 days of maturation, the higher strengths reached mixtures without replacing GGBFS. In terms of resistance to freeze-thaw processes, the largest decrease (almost 20%) of flexural strength was achieved by a mixture with 30% of GGBFS replacement by FA. No fundamental differences were found for the mixtures in the FTIR analysis. |
| first_indexed | 2024-03-10T03:05:10Z |
| format | Article |
| id | doaj.art-cab486d887a24e7cb5232c4dd4d863e9 |
| institution | Directory Open Access Journal |
| issn | 2073-4352 |
| language | English |
| last_indexed | 2024-03-10T03:05:10Z |
| publishDate | 2022-04-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Crystals |
| spelling | doaj.art-cab486d887a24e7cb5232c4dd4d863e92023-11-23T10:34:43ZengMDPI AGCrystals2073-43522022-04-0112563310.3390/cryst12050633Influence of Fly Ash Denitrification on Properties of Hybrid Alkali-Activated CompositesLukáš Procházka0Jana Boháčová1Barbara Vojvodíková2Faculty of Civil Engineering, VSB-Technical University of Ostrava, L. Podeste 1875, 70800 Ostrava, Czech RepublicFaculty of Civil Engineering, VSB-Technical University of Ostrava, L. Podeste 1875, 70800 Ostrava, Czech RepublicFaculty of Civil Engineering, VSB-Technical University of Ostrava, L. Podeste 1875, 70800 Ostrava, Czech RepublicThis article deals with the possibility of partial replacement of blast furnace slag (GGBFS) with fly ash after denitrification (FAD) in alkali-activated materials. Physical-mechanical and durability properties were tested, hydration reaction was monitored, and infrared spectroscopy was performed. Results were compared between mixtures prepared with fly ash without denitrification (FA), and also with a mixture based only on GGBFS. The basic result is that hybrid alkali-systems with FAD show similar trends to FA. The significant effect of fly ash is manifested in terms of its resistance to freeze-thaw processes. Reactions in a calorimeter show a slower development of reactions with increasing replacement of GGBFS due to the lower reactivity of the fly ash. Through testing the leaching resistance, a decrease in flexural strength was found. This may be due to the descaling of the main hydration product, C–(A)–S–H gel. After 28 days of maturation, compressive strengths of all monitored mixtures ranged from 96 to 102 MPa. The flexural strengths ranged from 6.8 to 8.0 MPa. After 28 days of maturation, the higher strengths reached mixtures without replacing GGBFS. In terms of resistance to freeze-thaw processes, the largest decrease (almost 20%) of flexural strength was achieved by a mixture with 30% of GGBFS replacement by FA. No fundamental differences were found for the mixtures in the FTIR analysis.https://www.mdpi.com/2073-4352/12/5/633blast furnace granulated slagsilica fly ashalkali-activated materialsdenitrificationmaterial engineering |
| spellingShingle | Lukáš Procházka Jana Boháčová Barbara Vojvodíková Influence of Fly Ash Denitrification on Properties of Hybrid Alkali-Activated Composites Crystals blast furnace granulated slag silica fly ash alkali-activated materials denitrification material engineering |
| title | Influence of Fly Ash Denitrification on Properties of Hybrid Alkali-Activated Composites |
| title_full | Influence of Fly Ash Denitrification on Properties of Hybrid Alkali-Activated Composites |
| title_fullStr | Influence of Fly Ash Denitrification on Properties of Hybrid Alkali-Activated Composites |
| title_full_unstemmed | Influence of Fly Ash Denitrification on Properties of Hybrid Alkali-Activated Composites |
| title_short | Influence of Fly Ash Denitrification on Properties of Hybrid Alkali-Activated Composites |
| title_sort | influence of fly ash denitrification on properties of hybrid alkali activated composites |
| topic | blast furnace granulated slag silica fly ash alkali-activated materials denitrification material engineering |
| url | https://www.mdpi.com/2073-4352/12/5/633 |
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