He Jingjing, Wang Xuezhi, Han Leiying, Wang Siyue, Xin Ming
Power China Northwest Engineering Corporation Limited, Xi'an 710065, China.
School of Civil and Architectural Engineering, Liaoning University of Technology, Jinzhou 121000, China.
Materials (Basel). 2024 Aug 7;17(16):3928. doi: 10.3390/ma17163928.
The application of carbon fiber in cement matrix has some disadvantages, such as poor dispersion and poor interfacial adhesion. In order to improve the interaction between carbon fiber and cement matrix and improve the properties of cement-based composites, carbon fiber was modified by electrophoretic deposition of nano-graphene oxide (GO). In this paper, the effects of doping CF into the cement matrix before and after GO modification are studied comparatively in terms of electrical conductivity, electrothermal warming effect, and pressure-sensitive properties of the cement matrix. It was found that the GO-modified CF reduces both the electrical resistivity of cementitious composites and the required level of fiber incorporation compared to CF. The percolation threshold is 0.7 wt% for CF and 0.5 wt% for GO-CF. The GO-modified CF is more effective than CF as a conductive filler to enhance the electrothermal warming performance of the cement matrix. When the GO-CF doping rate is 0.5%, the specimen temperature increases most rapidly, and the temperature rise value reaches a maximum of up to 30.45 °C, which is twice that of the CF group. When the fiber content is 0.7%, the pressure sensitivity of the sample was the best. When the fiber content is 0.5%, GO-CF can improve the pressure sensitivity of cement mortar specimens, and increase the resistance change rate of the cement mortar specimens by 5.7%.
碳纤维在水泥基体中的应用存在一些缺点，如分散性差和界面粘结性差。为了改善碳纤维与水泥基体之间的相互作用并提高水泥基复合材料的性能，采用纳米氧化石墨烯（GO）电泳沉积法对碳纤维进行了改性。本文从水泥基体的电导率、电热升温效应和压敏性能等方面，对GO改性前后碳纤维掺杂到水泥基体中的效果进行了比较研究。结果发现，与未改性的碳纤维相比，GO改性的碳纤维降低了水泥基复合材料的电阻率，同时也降低了所需的纤维掺入量。碳纤维的渗流阈值为0.7 wt%，GO改性碳纤维的渗流阈值为0.5 wt%。作为导电填料，GO改性碳纤维比碳纤维更有效地提高了水泥基体的电热升温性能。当GO改性碳纤维的掺杂率为0.5%时，试样温度上升最快，升温值最高可达30.45℃，是碳纤维组的两倍。当纤维含量为0.7%时，样品的压敏性最佳。当纤维含量为0.5%时，GO改性碳纤维可提高水泥砂浆试件的压敏性，使水泥砂浆试件的电阻变化率提高5.7%。
