Experimental investigation of concrete columns strengthened with perforated internal carbon fiber reinforced polymer tubes

IF 7.1 2区材料科学 Q1 MATERIALS SCIENCE, COMPOSITES

Composite Structures Pub Date : 2026-05-01 Epub Date: 2026-01-28 DOI:10.1016/j.compstruct.2026.120114

Krzysztof Adam Ostrowski , Marcin Piechaczek , Oliwia Sikora

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引用次数: 0

Abstract

Fiber-reinforced polymer (FRP) composites have attracted significant attention in the strengthening of concrete structures because of their high mechanical efficiency and long-term durability relative to conventional materials. This study investigates a novel hybrid method of reinforcing self-compacting concrete (SCC) columns using internally placed perforated CFRP tubes and external CFRP confinement, also serves as lost formwork.

Axial compression tests were conducted to evaluate mechanical behavior, focusing on compressive strength, deformability, and stiffness. Four configurations were tested: unconfined specimens, internal-only reinforcement (I-series), external-only confinement (O-series), and combined internal-external reinforcement (hybrid O-1/I-1 and O-3/I-1). Holes (2.8 % surface area) were made in the CFRP tubes to improve the bond between core concrete and the external jacket.

The hybrid system (O-3/I-1) achieved the highest performance, increasing compressive strength by 104 % and deformability by 50 % compared to unconfined specimens. External confinement alone resulted in an 82 % strength increase and improved stiffness, while internal strengthening contributed to a 12–15 % increase in strength and provided sustained load-bearing capacity even after outer concrete cover had failed.

Analytical comparisons confirmed compatibility of test results with theoretical models. The findings highlight effectiveness of this composite technique for structural applications such as bridge piers and high-rise columns. Further research is recommended on factors like perforation geometry and column slenderness.

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内孔碳纤维增强聚合物管加固混凝土柱的试验研究

与传统材料相比，纤维增强聚合物（FRP）复合材料具有较高的力学效率和长期耐久性，在混凝土结构加固方面受到广泛关注。本研究探讨了一种新的混合方法，加强自密实混凝土（SCC）柱使用内部放置穿孔CFRP管和外部CFRP约束，也可作为丢失的模板。轴向压缩试验是为了评估力学行为，重点是抗压强度、变形能力和刚度。测试了四种配置：无约束试样、内部单独加固（i系列）、外部单独约束（o系列）和内外复合加固（O-1/I-1和O-3/I-1混合）。孔（2.8%的表面积）在CFRP管，以改善核心混凝土和外部护套之间的结合。混合系统（O-3/I-1）取得了最高的性能，与无侧限试样相比，抗压强度提高了104%，变形能力提高了50%。仅外部约束就能提高82%的强度和刚度，而内部加强则能提高12 - 15%的强度，即使在外部混凝土覆盖层失效后，也能提供持续的承载能力。分析比较证实了试验结果与理论模型的一致性。研究结果强调了这种复合技术在桥梁桥墩和高层柱等结构应用中的有效性。建议对射孔几何形状和柱长细等因素进行进一步研究。

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

Composite Structures 工程技术-材料科学：复合

CiteScore

12.00

自引率

12.70%

发文量

1246

审稿时长

78 days

期刊介绍： The past few decades have seen outstanding advances in the use of composite materials in structural applications. There can be little doubt that, within engineering circles, composites have revolutionised traditional design concepts and made possible an unparalleled range of new and exciting possibilities as viable materials for construction. Composite Structures, an International Journal, disseminates knowledge between users, manufacturers, designers and researchers involved in structures or structural components manufactured using composite materials. The journal publishes papers which contribute to knowledge in the use of composite materials in engineering structures. Papers deal with design, research and development studies, experimental investigations, theoretical analysis and fabrication techniques relevant to the application of composites in load-bearing components for assemblies, ranging from individual components such as plates and shells to complete composite structures.