Effect of Carbonation Treatment on the Properties of Steel Slag Aggregate
Steel slag is the waste slag generated after steel smelting, which has cementitious activity. However, untreated steel slag can damage the integrity of steel slag concrete due to its harmful expansion. This study prepared porous aggregates by mixing powdered steel slag, fly ash, and cement and carbo...
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MDPI AG
2023-08-01
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| Series: | Materials |
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| Online Access: | https://www.mdpi.com/1996-1944/16/17/5768 |
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| author | Jian Ma Guangjian Dai Feifei Jiang Ning Wang Yufeng Zhao Xiaodong Wang |
| author_facet | Jian Ma Guangjian Dai Feifei Jiang Ning Wang Yufeng Zhao Xiaodong Wang |
| author_sort | Jian Ma |
| collection | DOAJ |
| description | Steel slag is the waste slag generated after steel smelting, which has cementitious activity. However, untreated steel slag can damage the integrity of steel slag concrete due to its harmful expansion. This study prepared porous aggregates by mixing powdered steel slag, fly ash, and cement and carbonated them with CO<sub>2</sub> under high pressure conditions (0.2 MPa). The effect of carbonation on the performance of steel slag aggregate was studied using volume stability and crushing value. The effect of different carbonation conditions on the products was studied using X-ray diffraction (XRD) and thermogravimetric (TG) analyses, and the carbon sequestration efficiency of steel slag under different treatment methods was quantitatively evaluated. The research results indicate that untreated steel slag was almost completely destroyed and lost its strength after autoclave curing. With the increase in temperature and carbonation time, the performance of steel slag aggregate gradually improved and the pulverization rate, expansion rate, and crushing value gradually decreased. According to the experimental results of XRD and TG, it was found that the reaction between f-CaO (free CaO) and CO<sub>2</sub> in steel slag generated CaCO<sub>3</sub>, filling the pores inside the aggregate, which was the internal reason for the improvement of aggregate performance. After comparison, the best carbonation method was maintained at 55 °C for 72 h. After carbonation, the steel slag aggregate had a pulverization rate of 2.4%, an expansion rate of 0.23%, a crushing value of 23%, and a carbon sequestration efficiency of 11.27% per unit weight of aggregate. |
| first_indexed | 2024-03-10T23:19:46Z |
| format | Article |
| id | doaj.art-b67030ccb16347f6aa67cb011c7c142f |
| institution | Directory Open Access Journal |
| issn | 1996-1944 |
| language | English |
| last_indexed | 2024-03-10T23:19:46Z |
| publishDate | 2023-08-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Materials |
| spelling | doaj.art-b67030ccb16347f6aa67cb011c7c142f2023-11-19T08:25:37ZengMDPI AGMaterials1996-19442023-08-011617576810.3390/ma16175768Effect of Carbonation Treatment on the Properties of Steel Slag AggregateJian Ma0Guangjian Dai1Feifei Jiang2Ning Wang3Yufeng Zhao4Xiaodong Wang5College of Architecture and Civil Engineering, Jiangsu University of Science and Technology, Zhenjiang 212000, ChinaCollege of Architecture and Civil Engineering, Jiangsu University of Science and Technology, Zhenjiang 212000, ChinaSuzhou Institute of Technology, Jiangsu University of Science and Technology, Suzhou 215600, ChinaSuzhou Institute of Technology, Jiangsu University of Science and Technology, Suzhou 215600, ChinaSuzhou Institute of Technology, Jiangsu University of Science and Technology, Suzhou 215600, ChinaCollege of Architecture and Civil Engineering, Jiangsu University of Science and Technology, Zhenjiang 212000, ChinaSteel slag is the waste slag generated after steel smelting, which has cementitious activity. However, untreated steel slag can damage the integrity of steel slag concrete due to its harmful expansion. This study prepared porous aggregates by mixing powdered steel slag, fly ash, and cement and carbonated them with CO<sub>2</sub> under high pressure conditions (0.2 MPa). The effect of carbonation on the performance of steel slag aggregate was studied using volume stability and crushing value. The effect of different carbonation conditions on the products was studied using X-ray diffraction (XRD) and thermogravimetric (TG) analyses, and the carbon sequestration efficiency of steel slag under different treatment methods was quantitatively evaluated. The research results indicate that untreated steel slag was almost completely destroyed and lost its strength after autoclave curing. With the increase in temperature and carbonation time, the performance of steel slag aggregate gradually improved and the pulverization rate, expansion rate, and crushing value gradually decreased. According to the experimental results of XRD and TG, it was found that the reaction between f-CaO (free CaO) and CO<sub>2</sub> in steel slag generated CaCO<sub>3</sub>, filling the pores inside the aggregate, which was the internal reason for the improvement of aggregate performance. After comparison, the best carbonation method was maintained at 55 °C for 72 h. After carbonation, the steel slag aggregate had a pulverization rate of 2.4%, an expansion rate of 0.23%, a crushing value of 23%, and a carbon sequestration efficiency of 11.27% per unit weight of aggregate.https://www.mdpi.com/1996-1944/16/17/5768steel slagcarbonationexpansionvolume stabilitywaste managementsustainability |
| spellingShingle | Jian Ma Guangjian Dai Feifei Jiang Ning Wang Yufeng Zhao Xiaodong Wang Effect of Carbonation Treatment on the Properties of Steel Slag Aggregate Materials steel slag carbonation expansion volume stability waste management sustainability |
| title | Effect of Carbonation Treatment on the Properties of Steel Slag Aggregate |
| title_full | Effect of Carbonation Treatment on the Properties of Steel Slag Aggregate |
| title_fullStr | Effect of Carbonation Treatment on the Properties of Steel Slag Aggregate |
| title_full_unstemmed | Effect of Carbonation Treatment on the Properties of Steel Slag Aggregate |
| title_short | Effect of Carbonation Treatment on the Properties of Steel Slag Aggregate |
| title_sort | effect of carbonation treatment on the properties of steel slag aggregate |
| topic | steel slag carbonation expansion volume stability waste management sustainability |
| url | https://www.mdpi.com/1996-1944/16/17/5768 |
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