| 摘要: |
| 为研究聚乙烯醇（PVA）纤维和碳纳米管（CNTs）对混凝土力学性能的影响，制备了不同PVA纤维和CNTs掺量的混凝土试件来进行抗压、劈裂抗拉以及抗折试验，并通过数字图像相关（DIC）技术对试件在抗折试验下的裂缝扩展进行了全过程监测.结果表明：当PVA纤维体积分数和CNTs质量分数均为0.15%时，混凝土试件的力学性能最优；DIC应变云图直观展示了混凝土试件在抗折试验过程中的裂缝扩展，可以对裂缝的位置以及发育方向进行准确地判别；PVA纤维和CNTs通过桥接作用延缓了水泥基体中微裂缝的发展，改善了混凝土的微观结构，表现出正混杂效应. |
| 关键词: 混凝土 聚乙烯醇纤维 碳纳米管 力学性能 数字图像相关技术 微观结构 |
| DOI：10.3969/j.issn.1007-9629.2023.07.014 |
| 分类号:TU528.01 |
| 基金项目:国家自然科学基金资助项目（52178106）；陕西省杰出青年基金资助项目（2021JC-26） |
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| Effect of PVA Fiber and Carbon Nanotubes Modification on Mechanical Properties of Concrete |
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XU Yangchen, XING Guohua, HUANG Jiao, WU Xinyu, LU Yongjian
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School of Civil Engineering， Chang’an University， Xi’an 710061， China
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| Abstract: |
| To study the effect of polyvinyl alcohol（PVA） fiber and carbon nanotubes（CNTs） on the mechanical properties of concrete， the concrete specimens reinforced with different content of PVA fiber and CNTs were prepared for compressive， splitting tensile and flexural tests， and the crack propagation of specimens under the flexural test was monitored by digital image correlation （DIC） technology. The results show that 0.15% PVA fiber and 0.15% CNTs can make concrete specimen obtain the best mechanical properties. DIC strain nephogram visually describes the crack propagation of specimen during the flexural test， which can be applied to judge accurately the crack location and development direction. PVA fibers and CNTs delay the propagation of microcracks and improve the microstructure of concrete by bridging microcracks in cement matrix， exhibiting a positive hybrid effect. |
| Key words: concrete polyvinyl alcohol fiber carbon nanotube mechanical property digital image correlation（DIC） microstructure |
