Synergetic enhancement of shear strength and ductility in reinforced concrete beams using FRP-UHPC stay-in-place formwork

IF 6.4 1区工程技术 Q1 ENGINEERING, CIVIL

Engineering Structures Pub Date : 2025-09-29 DOI:10.1016/j.engstruct.2025.121453

Ke-Fan Weng , Ji-Xiang Zhu , Bo-Tao Huang , Jian-Guo Dai , Jian-Fei Chen

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引用次数: 0

Abstract

This study investigates the shear performance of reinforced concrete (RC) beams enhanced by Fiber-Reinforced Polymer (FRP)-Ultra-High-Performance Concrete (UHPC) stay-in-place permanent formwork. Twelve composite beams were fabricated and experimentally evaluated to understand the effects of various factors, including the shear span-to-depth ratio (1.57 vs. 2.52), fiber types in UHPC (steel vs. polyethylene fibers), and reinforcement using CFRP bars. The failure mechanisms and crack evolution were closely monitored using digital image correlation (DIC). Results revealed exceptional bonding performance between the FRP-UHPC formwork and cast-in-place concrete. Compared to control beams, the use of FRP-UHPC formwork significantly enhanced shear capacity by 40–65 %, accompanied by notable improvements in initial stiffness and post-crack stiffness. The integration of CFRP bars into the UHPC formwork effectively suppressed shear crack propagation, resulting in increased shear strength and controlled crack widths. Remarkably, a ductile shear failure mode was observed for the first time in composite beams (RU25-ST and RU25-ST-F), contrasting with conventional brittle shear failures. A theoretical analysis approach was proposed and validated, offering accurate predictions for the shear capacity of FRP-UHPC formwork-enhanced RC beams.

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使用FRP-UHPC原地模板协同增强钢筋混凝土梁的抗剪强度和延性

本文研究了纤维增强聚合物(FRP)-超高性能混凝土（UHPC）固定模板增强的钢筋混凝土（RC）梁的抗剪性能。研究人员制作了12根组合梁，并对其进行了实验评估，以了解各种因素的影响，包括剪切跨深比（1.57 vs. 2.52）、UHPC中的纤维类型（钢纤维vs.聚乙烯纤维）以及使用CFRP筋进行加固。利用数字图像相关技术（DIC）密切监测其破坏机制和裂纹演化。结果显示FRP-UHPC模板与现浇混凝土之间具有优异的粘结性能。与对照梁相比，FRP-UHPC模板的使用显著提高了40 - 65% %的抗剪能力，并显著改善了初始刚度和开裂后刚度。碳纤维布与UHPC模板的结合有效地抑制了剪切裂缝的扩展，提高了抗剪强度，控制了裂缝宽度。值得注意的是，在组合梁（RU25-ST和RU25-ST- f）中首次观察到韧性剪切破坏模式，而不是传统的脆性剪切破坏。提出并验证了一种理论分析方法，为FRP-UHPC模板增强RC梁的抗剪承载力提供了准确的预测。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Engineering Structures 工程技术-工程：土木

CiteScore

10.20

自引率

14.50%

发文量

1385

审稿时长

67 days

期刊介绍： Engineering Structures provides a forum for a broad blend of scientific and technical papers to reflect the evolving needs of the structural engineering and structural mechanics communities. Particularly welcome are contributions dealing with applications of structural engineering and mechanics principles in all areas of technology. The journal aspires to a broad and integrated coverage of the effects of dynamic loadings and of the modelling techniques whereby the structural response to these loadings may be computed. The scope of Engineering Structures encompasses, but is not restricted to, the following areas: infrastructure engineering; earthquake engineering; structure-fluid-soil interaction; wind engineering; fire engineering; blast engineering; structural reliability/stability; life assessment/integrity; structural health monitoring; multi-hazard engineering; structural dynamics; optimization; expert systems; experimental modelling; performance-based design; multiscale analysis; value engineering. Topics of interest include: tall buildings; innovative structures; environmentally responsive structures; bridges; stadiums; commercial and public buildings; transmission towers; television and telecommunication masts; foldable structures; cooling towers; plates and shells; suspension structures; protective structures; smart structures; nuclear reactors; dams; pressure vessels; pipelines; tunnels. Engineering Structures also publishes review articles, short communications and discussions, book reviews, and a diary on international events related to any aspect of structural engineering.