Flexure tests on narrow concrete beams strengthened with CFRP sheets end-locked by winding around twin-rods
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摘要: 为了抵抗粘贴碳纤维增强聚合物基复合材料(CFRP)加固钢筋混凝土结构中常见的剥离破坏,发明了将CFRP布端部以特定方式绕平行双杆实现自锁的方法。鉴于窄梁截面宽度有限,提出将CFRP布贴梁受拉底面布置后,用安装在梁侧面的双L形端锚装置固定双杆,形成侧锚底贴加固方案。完成了5根混凝土强度较低的矩形截面梁四点弯曲试验,其中4根采用上述锚固方式抗弯加固,检验了锚固效果,考察了CFRP布宽度及其沿全长与梁底面是否粘结对加固效果的影响。试验结果表明,采用本文方法进行加固后,端部剥离得以避免,中部剥离即使发生,或在无粘结加固梁受力后期,CFRP布仍能承担较大拉力,因此,极限荷载较对比梁有明显提高。比较而言,CFRP布与梁底有粘结时加固效果更好,CFRP布宽度加大也对提高承载力有益。Abstract: In order to prevent the debonding failure occurring in reinforced concrete beams strengthened with carbon fiber reinforced polymer (CFRP) sheets, a technique of self-locking anchorage which anchors the ends of CFRP strips by winding around twin rods in parallel in a particular way was invented. In view of the limited width of a narrow beam, a scheme with side anchorage and bottom bonding was proposed, i.e., placing the CFRP to the beam bottom and using bolts to fix the double L-shaped end device with twin rods to the beam side. Five rectangular beams with lower concrete strength were tested in four-point bending, including four beams strengthened in flexure by using above self-locking anchorage method. The feasibility of the new scheme was validated and the influence of the strip width and whether it is bonded with the bottom of beam were studied. The test results show that the strengthening method in this paper can avoid the end-debonding, and the strip can still carry large tension even when the intermediate debonding happens, or in the late loading stage of unbonded strengthened beams. Therefore, the ultimate load is obviously promoted as compared with the control beam. Comparatively, the specimens with bonded strips perform better than that with unbonded, and increasing the strip width is beneficial to enhancing the load bearing capacity of beams.
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Keywords:
- carbon fiber reinforced polymer(CFRP) /
- self-locking /
- anchorage /
- strengthening /
- concrete beam /
- flexure
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期刊类型引用(7)
1. 周朝阳,邓楷,林国制,汪毅. 纤维网格端锚自锁增强机制. 复合材料学报. 2024(07): 3668-3676 . 本站查看 2. 董坤,刘路,杨松,荆范华,郝爱江. 温度-荷载耦合作用下端锚CFRP加固RC梁受弯性能研究. 建筑结构学报. 2023(03): 213-222 . 百度学术 3. 周朝阳,于亚男,郭宇轩,汪毅. 钢筋混凝土窄梁侧挂混锚碳纤维布加固受弯性能试验研究. 建筑结构学报. 2023(05): 232-239 . 百度学术 4. 刘志山. 碳纤维布材在住宅结构加固中的应用和发展. 居舍. 2023(05): 39-41 . 百度学术 5. 杨凯,张雅丽,吴文杰. 桥梁裂缝修复用纤维增强塑料材料耐久性研究进展. 塑料助剂. 2023(01): 61-64 . 百度学术 6. 张鹏,赵晓冬,邓宇. 碳纤维布加固H型钢部分外包混凝土柱偏压延性系数影响因素分析. 混凝土. 2021(08): 42-46 . 百度学术 7. 叶华文,唐诗晴,段智超,杨哲,冉川. 纤维增强复合材料桥梁结构2019年度研究进展. 土木与环境工程学报(中英文). 2020(05): 192-200 . 百度学术 其他类型引用(5)
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