Viability of Using High Amounts of Steel Slag Aggregates to Improve the Circularity and Performance of Asphalt Mixtures
Steel slag is a byproduct generated as waste during the steelmaking process and can be considered a cost-effective and environmentally acceptable alternative to replace natural aggregates. Using steel slag aggregates (SSA) to produce asphalt mixtures promotes sustainability and circular economy prin...
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| Format: | Article |
| Language: | English |
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MDPI AG
2022-01-01
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| Series: | Applied Sciences |
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| Online Access: | https://www.mdpi.com/2076-3417/12/1/490 |
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| author | Caroline Moura Lucas Nascimento Carlos Loureiro Mafalda Rodrigues Joel Oliveira Hugo Silva |
| author_facet | Caroline Moura Lucas Nascimento Carlos Loureiro Mafalda Rodrigues Joel Oliveira Hugo Silva |
| author_sort | Caroline Moura |
| collection | DOAJ |
| description | Steel slag is a byproduct generated as waste during the steelmaking process and can be considered a cost-effective and environmentally acceptable alternative to replace natural aggregates. Using steel slag aggregates (SSA) to produce asphalt mixtures promotes sustainability and circular economy principles by using an industrial byproduct as a raw material. Thus, this work mainly aims to design more sustainable asphalt mixtures with high amounts of SSA that fit the circular economy expectations. This work developed two asphalt mixtures with SSA for surface (AC 14 surf) and binder/base (AC 20 bin/base) courses. Initially, the excellent wearing and polishing resistance of SSA and their good affinity with bitumen demonstrated the potential of this byproduct to be used in asphalt mixtures. Then, when analyzing the influence of using two different SSA incorporation rates (50% and a percentage close to 100%) in both asphalt mixtures, it was concluded that the use of SSA should be limited to 75% to avoid excessive air void contents and durability problems. The importance of considering the different particle densities of SSA and natural aggregates was highlighted during the mix design by defining a relationship between an effective and equivalent binder content. Finally, the mechanical performance of AC 14 and AC 20 with 75% SSA incorporation was compared to identical conventional mixtures produced with natural granite aggregates. The results obtained showed that the asphalt mixtures with 75% SSA have some workability problems due to the rough and porous surface of SSA. However, they present an excellent water sensitivity and permanent deformation resistance, surpassing the performance of the conventional asphalt mixtures. |
| first_indexed | 2024-03-10T03:48:53Z |
| format | Article |
| id | doaj.art-feedbc28d70546878b1e3974f12c1590 |
| institution | Directory Open Access Journal |
| issn | 2076-3417 |
| language | English |
| last_indexed | 2024-03-10T03:48:53Z |
| publishDate | 2022-01-01 |
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| series | Applied Sciences |
| spelling | doaj.art-feedbc28d70546878b1e3974f12c15902023-11-23T11:13:51ZengMDPI AGApplied Sciences2076-34172022-01-0112149010.3390/app12010490Viability of Using High Amounts of Steel Slag Aggregates to Improve the Circularity and Performance of Asphalt MixturesCaroline Moura0Lucas Nascimento1Carlos Loureiro2Mafalda Rodrigues3Joel Oliveira4Hugo Silva5ISISE—Institute for Sustainability and Innovation in Structural Engineering, Department of Civil Engineering, University of Minho, 4800-058 Guimaraes, PortugalCVR—Centre for Waste Valorisation, 4800-042 Guimaraes, PortugalISISE—Institute for Sustainability and Innovation in Structural Engineering, Department of Civil Engineering, University of Minho, 4800-058 Guimaraes, PortugalDST—Domingos da Silva Teixeira, 4700-727 Braga, PortugalISISE—Institute for Sustainability and Innovation in Structural Engineering, Department of Civil Engineering, University of Minho, 4800-058 Guimaraes, PortugalISISE—Institute for Sustainability and Innovation in Structural Engineering, Department of Civil Engineering, University of Minho, 4800-058 Guimaraes, PortugalSteel slag is a byproduct generated as waste during the steelmaking process and can be considered a cost-effective and environmentally acceptable alternative to replace natural aggregates. Using steel slag aggregates (SSA) to produce asphalt mixtures promotes sustainability and circular economy principles by using an industrial byproduct as a raw material. Thus, this work mainly aims to design more sustainable asphalt mixtures with high amounts of SSA that fit the circular economy expectations. This work developed two asphalt mixtures with SSA for surface (AC 14 surf) and binder/base (AC 20 bin/base) courses. Initially, the excellent wearing and polishing resistance of SSA and their good affinity with bitumen demonstrated the potential of this byproduct to be used in asphalt mixtures. Then, when analyzing the influence of using two different SSA incorporation rates (50% and a percentage close to 100%) in both asphalt mixtures, it was concluded that the use of SSA should be limited to 75% to avoid excessive air void contents and durability problems. The importance of considering the different particle densities of SSA and natural aggregates was highlighted during the mix design by defining a relationship between an effective and equivalent binder content. Finally, the mechanical performance of AC 14 and AC 20 with 75% SSA incorporation was compared to identical conventional mixtures produced with natural granite aggregates. The results obtained showed that the asphalt mixtures with 75% SSA have some workability problems due to the rough and porous surface of SSA. However, they present an excellent water sensitivity and permanent deformation resistance, surpassing the performance of the conventional asphalt mixtures.https://www.mdpi.com/2076-3417/12/1/490steel slag aggregates (SSA)mix designasphalt pavementsmechanical performancecircular economy |
| spellingShingle | Caroline Moura Lucas Nascimento Carlos Loureiro Mafalda Rodrigues Joel Oliveira Hugo Silva Viability of Using High Amounts of Steel Slag Aggregates to Improve the Circularity and Performance of Asphalt Mixtures Applied Sciences steel slag aggregates (SSA) mix design asphalt pavements mechanical performance circular economy |
| title | Viability of Using High Amounts of Steel Slag Aggregates to Improve the Circularity and Performance of Asphalt Mixtures |
| title_full | Viability of Using High Amounts of Steel Slag Aggregates to Improve the Circularity and Performance of Asphalt Mixtures |
| title_fullStr | Viability of Using High Amounts of Steel Slag Aggregates to Improve the Circularity and Performance of Asphalt Mixtures |
| title_full_unstemmed | Viability of Using High Amounts of Steel Slag Aggregates to Improve the Circularity and Performance of Asphalt Mixtures |
| title_short | Viability of Using High Amounts of Steel Slag Aggregates to Improve the Circularity and Performance of Asphalt Mixtures |
| title_sort | viability of using high amounts of steel slag aggregates to improve the circularity and performance of asphalt mixtures |
| topic | steel slag aggregates (SSA) mix design asphalt pavements mechanical performance circular economy |
| url | https://www.mdpi.com/2076-3417/12/1/490 |
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