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硅酸盐通报 ›› 2023, Vol. 42 ›› Issue (2): 454-462.

所属专题: 水泥混凝土

• 水泥混凝土 • 上一篇    下一篇

聚乙烯醇纤维混凝土动态断裂过程试验研究

杨国梁, 李峰, 张志飞, 毕京九, 董智文, 李影   

  1. 中国矿业大学(北京)力学与建筑工程学院,北京 100083
  • 收稿日期:2022-09-25 修订日期:2022-10-23 出版日期:2023-02-15 发布日期:2023-03-07
  • 通信作者: 李 峰,硕士研究生。E-mail:lifeng980627@163.com
  • 作者简介:杨国梁(1979—),男,博士,副教授。主要从事防护工程和岩石动力学研究。E-mail:yanggl531@163.com

Experimental Study on Dynamic Fracture Process of Polyvinyl Alcohol Fiber Concrete

YANG Guoliang, LI Feng, ZHANG Zhifei, BI Jingjiu, DONG Zhiwen, LI Ying   

  1. School of Mechanics and Architectural Engineering, China University of Mining and Technology-Beijing, Beijing 100083, China
  • Received:2022-09-25 Revised:2022-10-23 Online:2023-02-15 Published:2023-03-07

摘要: 为探究纤维体积掺量对聚乙烯醇纤维增强水泥基复合材料(PVA-ECC)断裂过程的影响,基于50 mm的分离式霍普金森压杆(SHPB)装置对不同纤维体积掺量(0%、0.75%、1.50%、2.25%、3.00%)的PVA-ECC中心切槽半圆盘弯曲(NSCB)试件进行冲击试验,同时结合超高速数字图像(DIC)相关试验系统对PVA-ECC材料的动态断裂过程进行试验研究,得到了预制裂纹尖端张开位移的变化规律以及各组试件的临界裂缝尖端张开位移(CTODC)。结果表明,当不添加PVA纤维或添加较少(小于1.50%)时,裂尖宏观裂纹基本出现在裂尖荷载的峰值时刻处,而随着PVA纤维掺量的增加,裂尖宏观裂纹的出现显著早于裂尖荷载的峰值时刻,并且纤维体积掺量越大,裂尖宏观裂纹出现得越早,裂纹扩展至完全断裂的时间也显著增加。添加聚乙烯醇纤维可以显著提高混凝土试件的CTODC值,提高试件的阻裂能力,相同冲击荷载下,体积掺量为2.25%的聚乙烯醇纤维试件具有较大的CTODC值。

关键词: PVA-ECC, 分离式霍普金森压杆, 中心切槽半圆盘弯曲试件, 动态断裂韧度, 数字图像相关, 裂缝尖端张开位移

Abstract: In order to explore the effect of fiber volume content on the fracture process of polyvinyl alcohol fiber reinforced engineering cementitious composites (PVA-ECC), the split Hopkinson pressure bar (SHPB) device based on 50 mm was used for different fiber volume content (0%, 0.75%, 1.50%, 2.25%, 3.00%) of PVA-ECC notched semi-circular bend (NSCB) specimens for impact test, and combined with ultra-high-speed digital image correlate (DIC) test system for PVA-ECC materials. The dynamic fracture process was experimentally studied, and the variation law of the prefabricated crack tip opening displacement and the critical crack tip opening displacement (CTODC) value of each group of specimens were obtained. The results show that when no PVA fiber is added or a small amount (less than 1.50%) is added, the macroscopic crack at the crack tip appears basically at the peak moment of the crack tip load, and with the increase of the PVA fiber content, the macroscopic crack at the crack tip appears. It appears significantly earlier than the peak time of the crack tip load, and the larger the fiber volume content is, the earlier the crack tip macro crack appears, and the time for the crack to expand to complete fracture also increases significantly. The addition of polyvinyl alcohol fibers significantly improves the performance of concrete specimens. The increase of CTODC value can improve the crack resistance of the specimen. Under the same impact load, the specimen added with 2.25% polyvinyl alcohol fiber has a larger CTODC value.

Key words: PVA-ECC, split Hopkinson press bar, notched semi-circular bend specimen, dynamic fracture toughness, digital image correlate, crack tip opening displacement

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