Experimental and Numerical Study on Reinforced Concrete Columns Strengthened with Lightweight Alkali-Activated Slag Concrete and X-Type Encased Steel
As a key load-bearing component in building structures, the effective strengthening of reinforced concrete (RC) columns is critical to enhancing their structural reliability and service life. To tackle the issue of excessive self-weight from the increasing section strengthening method and further op...
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MDPI AG
2025-05-01
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| Online Access: | https://www.mdpi.com/2075-5309/15/10/1692 |
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| author | Jing Zhu Zijie Wen Yuankai Li Xiaomeng Hou Yiqi Lu |
| author_facet | Jing Zhu Zijie Wen Yuankai Li Xiaomeng Hou Yiqi Lu |
| author_sort | Jing Zhu |
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| description | As a key load-bearing component in building structures, the effective strengthening of reinforced concrete (RC) columns is critical to enhancing their structural reliability and service life. To tackle the issue of excessive self-weight from the increasing section strengthening method and further optimize the seismic performance of encased steel strengthening, this paper presents a novel composite strengthening method for RC columns, which is characterized by using Lightweight Alkali-Activated Slag Concrete (LAASC) as the strengthening layer and an X-type encased steel structure. By conducting axial compression tests on six columns and utilizing in-depth research on small eccentric compression and hysteresis performance through numerical simulation, the specific effects of different strengthening materials and encased steel forms on the mechanical properties of the columns are systematically explored. Experimental results indicate that compared to ordinary concrete strengthening layers, LAASC can reduce the self-weight of the strengthening layer by 25%, boost the bearing capacity of the strengthened components by 37%, and enhance the vertical deformation capacity by 100%. Numerical simulation also confirms that X-type encased steel composite strengthening can effectively control bending deformation under small eccentric compression, reducing lateral deflection by 30–35% compared to un-strengthened columns. Under horizontal reciprocating loading, the cumulative energy dissipation of X-type encased steel composite-strengthened columns is 15–30% higher than that of traditional steel encased composite-strengthened columns, reflecting the diagonal bracing effect of the X-type batten plates. |
| format | Article |
| id | doaj-art-3739852cd5964ecab0acfb699401b5c7 |
| institution | Kabale University |
| issn | 2075-5309 |
| language | English |
| publishDate | 2025-05-01 |
| publisher | MDPI AG |
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| series | Buildings |
| spelling | doaj-art-3739852cd5964ecab0acfb699401b5c72025-08-20T03:47:48ZengMDPI AGBuildings2075-53092025-05-011510169210.3390/buildings15101692Experimental and Numerical Study on Reinforced Concrete Columns Strengthened with Lightweight Alkali-Activated Slag Concrete and X-Type Encased SteelJing Zhu0Zijie Wen1Yuankai Li2Xiaomeng Hou3Yiqi Lu4College of Civil Engineering and Architecture, Harbin University of Science and Technology, Harbin 150080, ChinaCollege of Civil Engineering and Architecture, Harbin University of Science and Technology, Harbin 150080, ChinaCollege of Civil Engineering and Architecture, Harbin University of Science and Technology, Harbin 150080, ChinaLab of the Smart Prevention and Mitigation of Civil Engineering Disasters of the Ministry of Industry and Information Technology, Harbin Institute of Technology, Harbin 150090, ChinaCollege of Civil Engineering and Architecture, Harbin University of Science and Technology, Harbin 150080, ChinaAs a key load-bearing component in building structures, the effective strengthening of reinforced concrete (RC) columns is critical to enhancing their structural reliability and service life. To tackle the issue of excessive self-weight from the increasing section strengthening method and further optimize the seismic performance of encased steel strengthening, this paper presents a novel composite strengthening method for RC columns, which is characterized by using Lightweight Alkali-Activated Slag Concrete (LAASC) as the strengthening layer and an X-type encased steel structure. By conducting axial compression tests on six columns and utilizing in-depth research on small eccentric compression and hysteresis performance through numerical simulation, the specific effects of different strengthening materials and encased steel forms on the mechanical properties of the columns are systematically explored. Experimental results indicate that compared to ordinary concrete strengthening layers, LAASC can reduce the self-weight of the strengthening layer by 25%, boost the bearing capacity of the strengthened components by 37%, and enhance the vertical deformation capacity by 100%. Numerical simulation also confirms that X-type encased steel composite strengthening can effectively control bending deformation under small eccentric compression, reducing lateral deflection by 30–35% compared to un-strengthened columns. Under horizontal reciprocating loading, the cumulative energy dissipation of X-type encased steel composite-strengthened columns is 15–30% higher than that of traditional steel encased composite-strengthened columns, reflecting the diagonal bracing effect of the X-type batten plates.https://www.mdpi.com/2075-5309/15/10/1692alkali-activated slag concretestrengthenaxial compression testhysteretic propertiesnumerical simulation |
| spellingShingle | Jing Zhu Zijie Wen Yuankai Li Xiaomeng Hou Yiqi Lu Experimental and Numerical Study on Reinforced Concrete Columns Strengthened with Lightweight Alkali-Activated Slag Concrete and X-Type Encased Steel Buildings alkali-activated slag concrete strengthen axial compression test hysteretic properties numerical simulation |
| title | Experimental and Numerical Study on Reinforced Concrete Columns Strengthened with Lightweight Alkali-Activated Slag Concrete and X-Type Encased Steel |
| title_full | Experimental and Numerical Study on Reinforced Concrete Columns Strengthened with Lightweight Alkali-Activated Slag Concrete and X-Type Encased Steel |
| title_fullStr | Experimental and Numerical Study on Reinforced Concrete Columns Strengthened with Lightweight Alkali-Activated Slag Concrete and X-Type Encased Steel |
| title_full_unstemmed | Experimental and Numerical Study on Reinforced Concrete Columns Strengthened with Lightweight Alkali-Activated Slag Concrete and X-Type Encased Steel |
| title_short | Experimental and Numerical Study on Reinforced Concrete Columns Strengthened with Lightweight Alkali-Activated Slag Concrete and X-Type Encased Steel |
| title_sort | experimental and numerical study on reinforced concrete columns strengthened with lightweight alkali activated slag concrete and x type encased steel |
| topic | alkali-activated slag concrete strengthen axial compression test hysteretic properties numerical simulation |
| url | https://www.mdpi.com/2075-5309/15/10/1692 |
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