Yakovlev Grigory, Vít Černý, Polyanskikh Irina, Gordina Anastasiya, Pudov Igor, Gumenyuk Alexander, Smirnova Olga
Department of Geotechnical Engineering and Building Materials, Kalashnikov Izhevsk State Technical University, Studencheskaya Str. 7, 426009 Izhevsk, Russia.
Faculty of Civil Engineering, Brno University of Technology, Vevěrí 95, CZ-6S1200 Brno, Czech Republic.
Materials (Basel). 2021 Jan 24;14(3):557. doi: 10.3390/ma14030557.
The research results presented in this article were obtained by joint scientific research on creatingcement materials with reduced impedance. It is known that functional additives added to impart electrically conductive properties have a negative impact on physical and mechanical characteristics of the material. This study suggests using the multiwall carbon nanotubes in the amount of 7% from binder mass as a functional additive. The results obtained prove that the addition of this amount of the modifier does not lead to a significant decrease of strength characteristics. Calcium nitrate in the amount of 1-7% was added in order to level the strength loss and to ensure the effective stable electrical conductivity. The multifunctionality of using this salt has been proven, which is manifested in the anti-frost and anticorrosive effects as well in enhancement of electrical conductivity. The optimal composition of the additive with 7% of carbon nanotubes and 3% of calcium nitrate ensures a reduced electrical impedance of cement matrix. The electrical conductivity was 2440 Ohm, while the decrease of strength properties was within 10% in comparison tothe control sample. The nature of changes in the microstructure were studied to determine the influence of complex modifications that showed significant changes in the morphology of the hydration products. The optimum electrical characteristics of cementitious materials are provided due to the uniform distribution of carbon nanotubes and the formation of a network of interconnected micropores filled with the solution of calcium nitrate that provides additional and stable electrical conductivity over time.
本文所展示的研究成果是通过关于制备低阻抗水泥材料的联合科研获得的。众所周知，为赋予导电性能而添加的功能添加剂会对材料的物理和力学特性产生负面影响。本研究建议使用占粘结剂质量7%的多壁碳纳米管作为功能添加剂。所获得的结果证明，添加该剂量的改性剂不会导致强度特性显著降低。添加1 - 7%的硝酸钙以平衡强度损失并确保有效的稳定导电性。已证明使用这种盐具有多功能性，体现在抗冻和防腐效果以及导电性增强方面。含有7%碳纳米管和3%硝酸钙的添加剂的最佳组成可确保水泥基体的电阻抗降低。电导率为2440欧姆，与对照样品相比，强度性能的降低在10%以内。研究了微观结构变化的性质，以确定复合改性的影响，复合改性显示出水化产物形态的显著变化。由于碳纳米管的均匀分布以及形成充满硝酸钙溶液的相互连接的微孔网络，随着时间的推移提供了额外且稳定的导电性，从而实现了水泥材料的最佳电学特性。
