Piezoresistivity of cement based material with small amount of graphite
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摘要: 通过减水剂将少量石墨加入水泥基材料中制成石墨水泥基材料试样,采用交流分压电路测量其电阻率,研究其在一次性加载破坏试验中的压敏特性.试验结果表明,低掺量石墨粉作为导电组份加入水泥基材料后会导致其强度降低,但可以使水泥基材料具有一定程度的压敏特性.随着石墨掺量的增加,各组试样电阻率的离散性变小,材料的压敏特性提高,在加载过程电阻率的波动变小.在本试验的测量方法下得到的石墨水泥基材料的压敏特性曲线与混凝土材料的应力应变曲线有相关性,试样的电阻率随着应力的增大而产生变化的过程大体可分为3个阶段,即波动阶段、稳定下降阶段和急剧下降阶段,分别对应混凝土材料应力应变关系的弹性变化、非弹性变化和应变迅速增大阶段.Abstract: Graphite-cement specimens were made by adding water reducing agent in cement, and the specimens- piezoresistivity in a destructive overload experiment was mensurated by a series connected AC circuit. The results present that, if a small amount of graphite was mixed in, the cement material-s uniaxial compressive strength will decrease, at the same time the material-s piezoresistence coefficient will ascend. As the amount of graphite was increased within a small range, the deviation of specimens- relative resistivity decreases, and the piezoresistivity of the material increases. Furthermore, the resistivity of the specimens becomes stable while being loaded. By examining the piezoresistivity curves of the graphite-cement material, similar shape with the stress-strain curves can be got in these experiments. There are three stages while the material-s relative resistivity is changing along with the increase of stress imposed on it which are undulate stage, slowly descend stage and rapidly descend stage. These stages are accordant to the three stages of the failure of cement based material, which are elastic stage, elastic-plastic stage and failure stage.
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Key words:
- graphite /
- cement /
- relative resistivity /
- piezoresistivity
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[1] Chung D D L.Self-monitoring structural materials [J].Materials Science and Engineering,1998,22(2):57-78 [2] 毛起炤,陈品华,赵斌元,等.小应力下炭纤维增强水泥的压敏性和温敏性[J].材料研究学报,1997,22(3):322-324 Mao Qizhao,Chen Pinhua,Zhao Binyuan,et al.Compression-sensitivity and temperature-sensitivity of carbon fibre reinforced cement under low stresses [J].Chinese Journal of Materials Research,1997,22(3):322-324 (in Chinese) [3] 吴科如,陈兵,姚武.碳纤维机敏水泥基材料性能研究[J].同济大学学报,2002,30(4):456-463 Wu Keru,Chen Bing,Yao Wu.Smart propertyes of carbon fiber reinforced cement based composite [J].Journal of Tongji University,2002,30(4):456-463 (in Chinese) [4] 关新春,欧进萍,韩宝国,等.碳纤维机敏混凝土材料的研究与进展[J].哈尔滨建筑大学学报,2002,35(6):55-59 Guan Xinchun,Ou Jinping,Han Baoguo,et al.State of art of carbon fiber reinforced concrete [J].Journal of Harbin University of C.E.& Architecture,2002,35(6):55-59 (in Chinese) [5] 韩宝国,关新春,欧进萍.导电掺和料形态与水泥基材料压敏性的相关性[J].复合材料学报,2004,21(3):137-141 Han Baoguo,Guan Xinchun,Ou Jinping.Correlation between shape of electric admixtures and piezoresistive effect of cement based composite materials [J].Acta Materiae Compositae Sinica,2004,21(3):137-141(in Chinese) [6] 范晓明,董旭,孙明清,等.石墨水泥基复合材料的导电及压敏特性研究[J].武汉理工大学学报,2009,31(12):12-14 Fan Xiaoming,Dong Xu,Sun Mingqing,et al.Research on the electric characteristic and pressure sensitivity of graphite-cement based composites [J].Journal of Wuhan University of Technology,2009,31(12):12-14(in Chinese) [7] 韩宝国,关新春,欧进萍.碳纤维水泥石电阻测试方法研究[J].玻璃钢/复合材料,2003(6):6-8,51 Han Baoguo,Guan Xinchun,Ou JinPing.Study of test method for resistance of carbon fiber reinforced cement [J].Fiber Reinforced Plastics/Composites,2003(6):6-8,51 (in Chinese) [8] 毛起炤,孙明清,陈品华.CFRC试块体积电阻和表面电阻的研究[J].武汉工业大学学报,1997,19(2):65-67 Mao Qizhao,Sun Mingqing,Chen Pinhua.Study on volume resistance and surface resistance of CFRC [J].Journal of WuHan University of Technology.1997,19(2):65-67 (in Chinese) [9] Kumar M P,Monteiro Paulo J M.混凝土微观结构、性能和材料[M].3版.北京:中国电力出版社,2008:40-41 Kumar M P,Monteiro Paulo J M.Concrete:microstructure,properties,and materials [M].3rd ed.Beijing:China Electric Power Press,2008:40-41 (in Chinese) [10] 毛起炤,赵斌元,沈大荣,等.水泥基碳纤维复合材料压敏性的研究[J].复合材料学报,1996,13(4):8-11 Mao Qizhao,Zhao Binyuan,Shen Darong,et al.Study on the compression sensibility of cement matrix carbon fiber composite [J].Acta Materiae Compositea Sinica,1996,13(4):8-11 (in Chinese)
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