Cracking behavior of hollow ultra-high-performance concrete beams reinforced with CFRP bars

IF 3.9 2区工程技术 Q1 ENGINEERING, CIVIL

Structures Pub Date : 2025-04-15 DOI:10.1016/j.istruc.2025.108928

Zongze Li , Haitang Zhu , Lin Yang , Dongdong Ji

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引用次数: 0

Abstract

This study focuses on developing cost-effective ultra-high-performance concrete (UHPC) and optimizing beam cross-sectional geometries to enhance the economic viability of UHPC applications. Six hollow UHPC beams reinforced with CFRP bars (CFRP-UHPC beams) were fabricated and subjected to cyclic loading via four-point bending tests. The research investigates the effects of varying CFRP reinforcement ratios, hollow shapes (double circular and rectangular), and hollow ratios on the flexural performance of these beams. A comprehensive analysis was conducted, evaluating failure modes, crack propagation, characteristic load, deformation, and crack width. The results indicate that the newly developed UHPC containing coarse aggregates reduced costs by 43.34 % compared to conventional types and achieved scalability beyond 400 mm. A consistent failure mode was observed across all hollow beams, characterized by concrete crushing at the beam's top, initiating from the weakest point in the compression zone and progressing towards the mid-span or loading point. Reducing the cross-sectional hollow ratio significantly enhanced the flexural performance of the beams, improving cracking load, control load, ultimate load, deformation capacity, and effectively suppressing crack generation and propagation. Conversely, increasing the CFRP reinforcement ratio had the opposite effect. The influence of the hollow ratio on crack resistance was more pronounced in beams with higher hollow ratios. Rectangular hollow beams exhibited superior deformation and crack resistance compared to circular hollow beams at the same hollow ratio. A calculation model for the maximum crack width of hollow beams was developed based on composite material mechanics theory, with predicted results showing good agreement with experimental data.

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CFRP筋加固超高性能空心混凝土梁的开裂性能

本研究的重点是开发具有成本效益的超高性能混凝土（UHPC）和优化梁的截面几何形状，以提高UHPC应用的经济可行性。制作了6根CFRP筋加固的UHPC空心梁（CFRP-UHPC梁），并进行了四点弯曲循环加载试验。该研究调查了不同碳纤维布配筋率、空心形状（双圆形和矩形）和空心比例对这些梁的抗弯性能的影响。进行了综合分析，评估了破坏模式、裂纹扩展、特征载荷、变形和裂纹宽度。结果表明，新研制的含粗骨料的超高性能混凝土与常规类型相比，成本降低43.34 %，可扩展性超过400 mm。在所有空心梁上观察到一致的破坏模式，其特征是混凝土在梁的顶部破碎，从压缩区的最薄弱点开始，向跨中或加载点发展。降低截面空心比可显著提高梁的抗弯性能，提高开裂荷载、控制荷载、极限荷载、变形能力，有效抑制裂缝的产生和扩展。相反，增加CFRP配筋率则有相反的效果。空心比对梁抗裂性能的影响在空心比较高的梁中更为明显。在相同的空心比下，矩形空心梁的抗变形和抗裂性能优于圆形空心梁。基于复合材料力学理论，建立了空心梁最大裂缝宽度的计算模型，预测结果与实验数据吻合较好。

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

Structures Engineering-Architecture

CiteScore

5.70

自引率

17.10%

发文量

1187

期刊介绍： Structures aims to publish internationally-leading research across the full breadth of structural engineering. Papers for Structures are particularly welcome in which high-quality research will benefit from wide readership of academics and practitioners such that not only high citation rates but also tangible industrial-related pathways to impact are achieved.