Reactivity of aqueous carbonated cement pastes: Effect of chemical composition and carbonation conditions
Aqueous carbonation of end-of-life concrete fines is a promising method to alleviate greenhouse gas emissions by CO2 sequestration from point-source emitters. This produces a valuable material that can be utilized in new cement formulations. This study investigates effects of the composition of ceme...
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| Language: | English |
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Elsevier
2024-11-01
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| Series: | Journal of CO2 Utilization |
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| Online Access: | http://www.sciencedirect.com/science/article/pii/S2212982024003056 |
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| author | Fábio Maia Neto Ruben Snellings Jørgen Skibsted |
| author_facet | Fábio Maia Neto Ruben Snellings Jørgen Skibsted |
| author_sort | Fábio Maia Neto |
| collection | DOAJ |
| description | Aqueous carbonation of end-of-life concrete fines is a promising method to alleviate greenhouse gas emissions by CO2 sequestration from point-source emitters. This produces a valuable material that can be utilized in new cement formulations. This study investigates effects of the composition of cement pastes and of the carbonation conditions on the reactivity and phase assemblage for aqueous carbonated Portland cement pastes incorporating silica fume, fly ash, and blast furnace slag. Results from 27Al and 29Si NMR show that hydration of the carbonated pastes under reactivity test conditions lead to phase assemblages dominated by a C-(A)-S-H phase, with reduced Al/Si ratio, as well as by ettringite and hemi/monocarbonate AFm phases. The results from the reactivity tests demonstrate that the carbonated blended cement pastes exhibit superior reactivity compared to carbonated neat Portland cement paste because of their increased fraction of reactive alumina and silica species. The variations in carbonation conditions (i.e., temperature, CO2 gas concentration, and solution composition) do not alter significantly the reactivity of the carbonated pastes. These findings demonstrate the robustness of aqueous carbonation of concrete fines and support its wider application as a mean to reduce CO2 emissions and enhance circularity of cement-based materials. |
| format | Article |
| id | doaj-art-7651616f4e8446daaeff15391a30c1a5 |
| institution | Kabale University |
| issn | 2212-9839 |
| language | English |
| publishDate | 2024-11-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Journal of CO2 Utilization |
| spelling | doaj-art-7651616f4e8446daaeff15391a30c1a52024-11-18T04:33:10ZengElsevierJournal of CO2 Utilization2212-98392024-11-0189102970Reactivity of aqueous carbonated cement pastes: Effect of chemical composition and carbonation conditionsFábio Maia Neto0Ruben Snellings1Jørgen Skibsted2Department of Chemistry and Interdisciplinary Nanoscience Center (iNANO), Aarhus University, Aarhus C DK-8000, DenmarkEarth and Environmental Sciences, Materials Engineering, KU Leuven, Celestijnenlaan 200E, Leuven 3001, BelgiumDepartment of Chemistry and Interdisciplinary Nanoscience Center (iNANO), Aarhus University, Aarhus C DK-8000, Denmark; Correspondence to: Aarhus University, Department of Chemistry and Interdisciplinary Nanoscience Center (iNANO), Langelandsgade 140, Aarhus C DK-8000, Denmark.Aqueous carbonation of end-of-life concrete fines is a promising method to alleviate greenhouse gas emissions by CO2 sequestration from point-source emitters. This produces a valuable material that can be utilized in new cement formulations. This study investigates effects of the composition of cement pastes and of the carbonation conditions on the reactivity and phase assemblage for aqueous carbonated Portland cement pastes incorporating silica fume, fly ash, and blast furnace slag. Results from 27Al and 29Si NMR show that hydration of the carbonated pastes under reactivity test conditions lead to phase assemblages dominated by a C-(A)-S-H phase, with reduced Al/Si ratio, as well as by ettringite and hemi/monocarbonate AFm phases. The results from the reactivity tests demonstrate that the carbonated blended cement pastes exhibit superior reactivity compared to carbonated neat Portland cement paste because of their increased fraction of reactive alumina and silica species. The variations in carbonation conditions (i.e., temperature, CO2 gas concentration, and solution composition) do not alter significantly the reactivity of the carbonated pastes. These findings demonstrate the robustness of aqueous carbonation of concrete fines and support its wider application as a mean to reduce CO2 emissions and enhance circularity of cement-based materials.http://www.sciencedirect.com/science/article/pii/S2212982024003056Alumina-silica gelCO2 sequestrationRecycled concreteR3 testSCM - supplementary cementitious materialsSolid-state NMR |
| spellingShingle | Fábio Maia Neto Ruben Snellings Jørgen Skibsted Reactivity of aqueous carbonated cement pastes: Effect of chemical composition and carbonation conditions Journal of CO2 Utilization Alumina-silica gel CO2 sequestration Recycled concrete R3 test SCM - supplementary cementitious materials Solid-state NMR |
| title | Reactivity of aqueous carbonated cement pastes: Effect of chemical composition and carbonation conditions |
| title_full | Reactivity of aqueous carbonated cement pastes: Effect of chemical composition and carbonation conditions |
| title_fullStr | Reactivity of aqueous carbonated cement pastes: Effect of chemical composition and carbonation conditions |
| title_full_unstemmed | Reactivity of aqueous carbonated cement pastes: Effect of chemical composition and carbonation conditions |
| title_short | Reactivity of aqueous carbonated cement pastes: Effect of chemical composition and carbonation conditions |
| title_sort | reactivity of aqueous carbonated cement pastes effect of chemical composition and carbonation conditions |
| topic | Alumina-silica gel CO2 sequestration Recycled concrete R3 test SCM - supplementary cementitious materials Solid-state NMR |
| url | http://www.sciencedirect.com/science/article/pii/S2212982024003056 |
| work_keys_str_mv | AT fabiomaianeto reactivityofaqueouscarbonatedcementpasteseffectofchemicalcompositionandcarbonationconditions AT rubensnellings reactivityofaqueouscarbonatedcementpasteseffectofchemicalcompositionandcarbonationconditions AT jørgenskibsted reactivityofaqueouscarbonatedcementpasteseffectofchemicalcompositionandcarbonationconditions |