Influence of Activation Parameters on the Mechanical and Microstructure Properties of an Alkali-Activated BOF Steel Slag
Steel slag (SS) is a secondary material from steelmaking production with little commercial value. Its volumetric expansion and low reactivity limit the use of SS in Portland cement (PC)-based materials. This study investigated the potential use of basic oxygen furnace (BOF) slag as a single precurso...
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MDPI AG
2022-12-01
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| Series: | Applied Sciences |
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| Online Access: | https://www.mdpi.com/2076-3417/12/23/12437 |
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| author | Vitor A. Nunes Prannoy Suraneni Augusto C. S. Bezerra Carlos Thomas Paulo H. R. Borges |
| author_facet | Vitor A. Nunes Prannoy Suraneni Augusto C. S. Bezerra Carlos Thomas Paulo H. R. Borges |
| author_sort | Vitor A. Nunes |
| collection | DOAJ |
| description | Steel slag (SS) is a secondary material from steelmaking production with little commercial value. Its volumetric expansion and low reactivity limit the use of SS in Portland cement (PC)-based materials. This study investigated the potential use of basic oxygen furnace (BOF) slag as a single precursor in alkali-activated matrices (AAMs). Six AAM pastes were assessed by changing the silica modulus (0.75, 1.50 and 2.22) and the sodium concentration (4% or 6% Na<sub>2</sub>O—wt. SS). The early hydration was assessed using isothermal calorimetry (IC), followed by the assessment of the mechanical performance (compressive strength), apparent porosity, and structure and microstructure characterization (X-ray diffraction, thermogravimetric analysis and scanning electron microscopy). The results indicated that although the BOF slag may be considered a low-reactivity material, the alkaline environment effectively dissolved important crystalline phases to produce hydrates (reaction products). An optimized combination of activator sources was achieved with 4% Na<sub>2</sub>O and a silica modulus of 1.50–2.22, with a compressive strength up to 20 MPa, a significant amount of reaction products (C-S-H/C-A-S-H gels), and low initial and cumulative heat release. Those properties will help to promote SS recycling use in future engineering projects that do not require high-strength materials. |
| first_indexed | 2024-03-09T17:51:59Z |
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| id | doaj.art-17cee3022a9f490489257d87b974a8f6 |
| institution | Directory Open Access Journal |
| issn | 2076-3417 |
| language | English |
| last_indexed | 2024-03-09T17:51:59Z |
| publishDate | 2022-12-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Applied Sciences |
| spelling | doaj.art-17cee3022a9f490489257d87b974a8f62023-11-24T10:36:32ZengMDPI AGApplied Sciences2076-34172022-12-0112231243710.3390/app122312437Influence of Activation Parameters on the Mechanical and Microstructure Properties of an Alkali-Activated BOF Steel SlagVitor A. Nunes0Prannoy Suraneni1Augusto C. S. Bezerra2Carlos Thomas3Paulo H. R. Borges4Department of Civil Engineering, Nova Gameleira Campus II, Federal Centre for Technological Education of Minas Gerais (CEFET-MG), Av. Amazonas 7675, Belo Horizonte 30510-000, BrazilDepartment of Civil and Architectural Engineering, University of Miami, Coral Gables, FL 33146, USADepartment of Civil Engineering, Nova Gameleira Campus II, Federal Centre for Technological Education of Minas Gerais (CEFET-MG), Av. Amazonas 7675, Belo Horizonte 30510-000, BrazilLADICIM—Laboratory of Materials Science and Engineering, Escuela Técnica Superior de Ingenieros de Caminos, Canales y Puertos, University of Cantabria, 39005 Santander, SpainDepartment of Civil Engineering, Nova Gameleira Campus II, Federal Centre for Technological Education of Minas Gerais (CEFET-MG), Av. Amazonas 7675, Belo Horizonte 30510-000, BrazilSteel slag (SS) is a secondary material from steelmaking production with little commercial value. Its volumetric expansion and low reactivity limit the use of SS in Portland cement (PC)-based materials. This study investigated the potential use of basic oxygen furnace (BOF) slag as a single precursor in alkali-activated matrices (AAMs). Six AAM pastes were assessed by changing the silica modulus (0.75, 1.50 and 2.22) and the sodium concentration (4% or 6% Na<sub>2</sub>O—wt. SS). The early hydration was assessed using isothermal calorimetry (IC), followed by the assessment of the mechanical performance (compressive strength), apparent porosity, and structure and microstructure characterization (X-ray diffraction, thermogravimetric analysis and scanning electron microscopy). The results indicated that although the BOF slag may be considered a low-reactivity material, the alkaline environment effectively dissolved important crystalline phases to produce hydrates (reaction products). An optimized combination of activator sources was achieved with 4% Na<sub>2</sub>O and a silica modulus of 1.50–2.22, with a compressive strength up to 20 MPa, a significant amount of reaction products (C-S-H/C-A-S-H gels), and low initial and cumulative heat release. Those properties will help to promote SS recycling use in future engineering projects that do not require high-strength materials.https://www.mdpi.com/2076-3417/12/23/12437basic oxygen furnace slagalkali-activated materialswaste recyclingactivation parametersmicrostructure properties |
| spellingShingle | Vitor A. Nunes Prannoy Suraneni Augusto C. S. Bezerra Carlos Thomas Paulo H. R. Borges Influence of Activation Parameters on the Mechanical and Microstructure Properties of an Alkali-Activated BOF Steel Slag Applied Sciences basic oxygen furnace slag alkali-activated materials waste recycling activation parameters microstructure properties |
| title | Influence of Activation Parameters on the Mechanical and Microstructure Properties of an Alkali-Activated BOF Steel Slag |
| title_full | Influence of Activation Parameters on the Mechanical and Microstructure Properties of an Alkali-Activated BOF Steel Slag |
| title_fullStr | Influence of Activation Parameters on the Mechanical and Microstructure Properties of an Alkali-Activated BOF Steel Slag |
| title_full_unstemmed | Influence of Activation Parameters on the Mechanical and Microstructure Properties of an Alkali-Activated BOF Steel Slag |
| title_short | Influence of Activation Parameters on the Mechanical and Microstructure Properties of an Alkali-Activated BOF Steel Slag |
| title_sort | influence of activation parameters on the mechanical and microstructure properties of an alkali activated bof steel slag |
| topic | basic oxygen furnace slag alkali-activated materials waste recycling activation parameters microstructure properties |
| url | https://www.mdpi.com/2076-3417/12/23/12437 |
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