Abstract: The influence of water content variation on the resistance and piezoresistivity of multi-wall carbon nanotube reinforced mortar was investigated by means of four times drying and three times wetting experiments. The results were compared with the cement mortar. It showed small impact on resistance and piezoresistivity of specimen with more water content. With decreasing water content, the change of resistance became significant, especially for the cement mortar. The magnitude of the piezoresistivity of composites became large. The piezoresistivity of CM was more sensitive to the change of water than MWCNTs/CM in this case. Moreover, the magnitude of piezoresistivity near the percolation during the wetting process was higher than the drying process. Finally, the mechanisms of piezoresistivity change of MWCNTs/CM were analyzed during the process. The equivalent circuits were obtained to explain the change of conductive network.
1 Wen S H, Chung D D L. Damage monitoring of cement paste by electrical resistance measurement[J]. Cem Concr Res, 2000,30:1979. 2 Wen S H, Chung D D L. Partial replacement of carbon fiber by carbon black inmultifunctional cement-matrix composites[J]. Carbon,2007,45(3):505. 3 Xiao H G, Li H, Ou J P. Modeling of piezoresistivity of carbon black filledcement-based composites under multi-axial strain[J].Sens Actuat A: Phys,2010,160:87. 4 Xiao H G, Li H, Ou J P. Strain sensing properties of cement-based sensors embedded at various stresszones in a bending concrete beam[J]. Sens Actuat A: Phys,2011,167:581. 5 Geng S N, Wang P, Ding T H. Properties of multi-walled carbon nanotube/silicone rubber composite pressure-sensitive elements[J]. J Tsinghua University,2012(8):1081(in Chinese). 耿胜男,王鹏,丁天怀. 多壁碳纳米管／硅橡胶复合材料压敏元件特性[J]. 清华大学学报,2012(8):1081. 6 Liu J H,Wu S Q, He C X,et al. Structure property and application of carbon nanotubes and carbon microtubes[J]. J Shenzhen University Science and Engineering,2013,30(1):1(in Chinese). 刘剑洪,吴双泉,何传新,等. 碳纳米管和碳微米管的结构、性质及其应用[J]. 深圳大学学报理工版,2013,30(1):1. 7 Yao W, Zuo J Q, Wu K R. Microstructure and thermoelectric properties of carbon nanotube-carbon fiber/cement composites[J]. J Funct Mater, 2013,44(13):1924(in Chinese). 姚武,左俊卿,吴科如. 碳纳米管-碳纤维／水泥基材料微观结构和热电性能[J].功能材料,2013,44(13):1924. 8 Liu Q L, Sun W, Ma Z X, et al. Effect of carbon nanotube on mechanical and 2D-3D microstructure properties of cement mortars with silica fume[J]. J Chin Ceram Soc, 2014,42(10):1266(in Chinese). 刘巧玲,孙伟,马正先,等.碳纳米管对硅灰/水泥砂浆力学和2D-3D微结构性能的影响[J].硅酸盐学报,2014,42(10):1266. 9 Li G Y, Wang P M, Zhao X H. Pressure-sensitive properties and microstructure of carbon nanotube reinforced cement composites[J]. Cem Concr Compos,2007,29:377. 10Han B, Yu X, Kwon E. A self-sensing carbon nanotube/cement composites for traffic monitoring[J]. Nanotechnology,2009,18:445. 11Han B, Yu X, Ou J P. Effect of water content on the piezoresistivity of MWNT/cement composites[J].J Mater Sci,2010,45:3714. 12Konsta-Gdoutos M S, Aza C A. Self sensing carbon nanotube (CNT) and nanofiber (CNF) cementitious composites for real time damage assessment in smart structures[J]. Cem Concr Compos,2014,53:162. 13Zhao X H, Li G B, Wang Y L, et al. Piezoresistivity of carbon fiber reinforced cement-matrix composites[J]. Acta Mater Compos Sin,2011,28(5):214(in Chinese). 赵晓华,李国宝,王玉林,等. 碳纤维增强水泥基复合材料的压阻效应[J].复合材料学报,2011,28(5):214. 14Li Gengying. Mechanical properties and smart properties of carbon nanotube cement based materials[D].Shanghai: Tongji University, 2007(in Chinese). 李庚英.碳纳米管水泥基材料的力学性能及机敏性能[D].上海:同济大学,2007. 15Xu S L, Liu J T, Li Q H. Mechanical properties and microstructure of multi-walled carbon nanotube-reinforced cement paste[J]. Constr Building Mater, 2015,76:16. 16Rajabipour F, Weiss J. Electrical conductivity of drying cement paste[J].Mater Struct, 2007,40:1143. 17 Philippi P C, Souza H A. Modeling moisture distribution and isothermal transfer in a heterogeneous porous material[J].Int J Flow, 1995,21(4):667.
渝公网安备50019002502923号 版权所有：《材料导报》编辑部
2017, Vol. 31 
