Research on Synergistic Enhancement of UHPC Cold Region Repair Performance by Steel Fibers and Early-Strength Agent
This study looked at the performance requirements of repair materials for concrete structures in cold regions, systematically analyzing the effects of steel fiber dosage (0.7–2.1%), early-strength agent PRIORITY dosage (6–10%), and their coupling effects on the workability, interfacial bond strength...
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| Language: | English |
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MDPI AG
2025-07-01
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| Series: | Buildings |
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| Online Access: | https://www.mdpi.com/2075-5309/15/15/2630 |
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| author | Ming Xie Zhangdong Wang Li’e Yin Hao Li |
| author_facet | Ming Xie Zhangdong Wang Li’e Yin Hao Li |
| author_sort | Ming Xie |
| collection | DOAJ |
| description | This study looked at the performance requirements of repair materials for concrete structures in cold regions, systematically analyzing the effects of steel fiber dosage (0.7–2.1%), early-strength agent PRIORITY dosage (6–10%), and their coupling effects on the workability, interfacial bond strength, and freeze–thaw resistance of rapid-hardening ultra-high-performance concrete (UHPC). Through fluidity testing, bond interface failure analysis, freeze–thaw cycle testing, and pore analysis, the mechanism of steel fibers and early-strength agent on the multi-dimensional performance of fast-hardening UHPC was revealed. The results showed that when the steel fiber dosage exceeded 1.4%, the flowability was significantly reduced, while a PRIORITY dosage of 8% improved the flowability by 20.5% by enhancing the paste lubricity. Single addition of steel fibers decreased the interfacial bond strength, but compound addition of 8% PRIORITY offset the negative impact by optimizing the filling effect of hydration products. Under freeze–thaw cycles, excessive steel fibers (2.1%) exacerbated the mass loss (1.67%), whereas a PRIORITY dosage of 8% increased the retention rate of relative dynamic elastic modulus by 10–15%. Pore analysis shows that the synergistic effect of 1.4% steel fiber and 8% PRIORITY can reduce the number of pores, optimize the pore distribution, and make the structure denser. The study determined that the optimal compound mixing ratio was 1.4% steel fibers and 8% PRIORITY. This combination ensures construction fluidity while significantly improving the interfacial bond durability and freeze–thaw resistance, providing a theoretical basis for the design of concrete repair materials in cold regions. |
| format | Article |
| id | doaj-art-d4ba9d0d33b6481cb6a3ad6c9399a034 |
| institution | Kabale University |
| issn | 2075-5309 |
| language | English |
| publishDate | 2025-07-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Buildings |
| spelling | doaj-art-d4ba9d0d33b6481cb6a3ad6c9399a0342025-08-20T03:36:39ZengMDPI AGBuildings2075-53092025-07-011515263010.3390/buildings15152630Research on Synergistic Enhancement of UHPC Cold Region Repair Performance by Steel Fibers and Early-Strength AgentMing Xie0Zhangdong Wang1Li’e Yin2Hao Li3Shaanxi Key Laboratory of Safety and Durability of Concrete Structures, Xijing University, Xi’an 710123, ChinaShaanxi Key Laboratory of Safety and Durability of Concrete Structures, Xijing University, Xi’an 710123, ChinaShaanxi Key Laboratory of Safety and Durability of Concrete Structures, Xijing University, Xi’an 710123, ChinaShaanxi Key Laboratory of Safety and Durability of Concrete Structures, Xijing University, Xi’an 710123, ChinaThis study looked at the performance requirements of repair materials for concrete structures in cold regions, systematically analyzing the effects of steel fiber dosage (0.7–2.1%), early-strength agent PRIORITY dosage (6–10%), and their coupling effects on the workability, interfacial bond strength, and freeze–thaw resistance of rapid-hardening ultra-high-performance concrete (UHPC). Through fluidity testing, bond interface failure analysis, freeze–thaw cycle testing, and pore analysis, the mechanism of steel fibers and early-strength agent on the multi-dimensional performance of fast-hardening UHPC was revealed. The results showed that when the steel fiber dosage exceeded 1.4%, the flowability was significantly reduced, while a PRIORITY dosage of 8% improved the flowability by 20.5% by enhancing the paste lubricity. Single addition of steel fibers decreased the interfacial bond strength, but compound addition of 8% PRIORITY offset the negative impact by optimizing the filling effect of hydration products. Under freeze–thaw cycles, excessive steel fibers (2.1%) exacerbated the mass loss (1.67%), whereas a PRIORITY dosage of 8% increased the retention rate of relative dynamic elastic modulus by 10–15%. Pore analysis shows that the synergistic effect of 1.4% steel fiber and 8% PRIORITY can reduce the number of pores, optimize the pore distribution, and make the structure denser. The study determined that the optimal compound mixing ratio was 1.4% steel fibers and 8% PRIORITY. This combination ensures construction fluidity while significantly improving the interfacial bond durability and freeze–thaw resistance, providing a theoretical basis for the design of concrete repair materials in cold regions.https://www.mdpi.com/2075-5309/15/15/2630UHPCinterfacial bond strengthfrost resistanceconcrete repair materialssteel fibers |
| spellingShingle | Ming Xie Zhangdong Wang Li’e Yin Hao Li Research on Synergistic Enhancement of UHPC Cold Region Repair Performance by Steel Fibers and Early-Strength Agent Buildings UHPC interfacial bond strength frost resistance concrete repair materials steel fibers |
| title | Research on Synergistic Enhancement of UHPC Cold Region Repair Performance by Steel Fibers and Early-Strength Agent |
| title_full | Research on Synergistic Enhancement of UHPC Cold Region Repair Performance by Steel Fibers and Early-Strength Agent |
| title_fullStr | Research on Synergistic Enhancement of UHPC Cold Region Repair Performance by Steel Fibers and Early-Strength Agent |
| title_full_unstemmed | Research on Synergistic Enhancement of UHPC Cold Region Repair Performance by Steel Fibers and Early-Strength Agent |
| title_short | Research on Synergistic Enhancement of UHPC Cold Region Repair Performance by Steel Fibers and Early-Strength Agent |
| title_sort | research on synergistic enhancement of uhpc cold region repair performance by steel fibers and early strength agent |
| topic | UHPC interfacial bond strength frost resistance concrete repair materials steel fibers |
| url | https://www.mdpi.com/2075-5309/15/15/2630 |
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